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August 25 2021

USB wiring diagram- Micro USB pinout, 7+ Images

If you are searching for the USB wiring diagram, you are at the right place. The wiring diagram includes any combination of different types of USB connectors. The most common after USB-type A to USB- type C is “micro USB- type B” to standard “USB-type A” which is generally presents in mobile phone chargers.

micro usb charger wiring diagram internal

USB wiring diagram comes in handy when USB port or connector either of them malfunctions or completely out of order, also for engineers and hobbyist who wants to explore the electronics wiring practically.

These cables breakdown occurs due to excessive use of USB wire (here excessive use means repetitive use of wire or connecting port in a short duration of time). Improper use like rugged applications, inappropriate inserting into port, i.e without checking port orientation.

Another practice is bending the wire greater than 90 degrees, which causes the copper wires in the bundle to get damaged due to its slightly brittle property. Copper is having one of the best malleability and ductility properties. And therefore copper is widely used as a conductor in a wire even having this property, the copper wire undergoes degradation.

Before wiring USB you need to know the pin-out diagram of USB. Below is the figure showing the pin-out diagram of the USB micro-B and USB-A wiring diagram.

Type-A USB pinout diagram, micro USB pinout diagram along with USB wiring diagram:

This cable is most commonly used in mobile charger for charging mobile phones and as a USB data cable to connect mobile devices to tranfer files and images between personal computers and phones.

usb wiring diagram micro usb pinout charger cable

Click here for the USB C 3.0 wiring diagram and charger cable internal wiring.

micro usb b pin out wiring, male USB A pinout wiring diagram

Description: USB wiring is simple but not that simple this is because on changing the frame of reference the pinout looks changed. It can be noticed that pin-out the front side be different than that of back side and thus it requires to check the connectivity of both ends with a digital multi-meter (above micro USB pinout made it simple for you).

Table of male USB-A pinout & USB-B pinout:

Pin no.	Name	Wire code	Description
1	VCC	Red/ Orange	+5V (dc power)
2	D-	White/ Gold	Data- (data from device to host)
3	D+	Green	Data+ (data from host to device)
4	GND	Black/ Blue	0V (dc ground)

The table showing pin number and their nomenclature along with its function in short.

Pin no.1 showing the power supply (+VDD) through that pin the power is supplied to the device or any equipment which is also an indicator of handshake signal, means “the device is connected”.
According to the USB standard power supply is +5V.(but note that the capacity of the power supply is different for different USB versions)
Whereas, “pin no. 2” (-D) is used as a differential data pin, similarly “pin no. 3” (+D) is also used as a differential data pin.
The work of the differential data pin is to send and receive the data in a particular format called USB protocol.
Pin no. 4 is used as ground. The color code for the wire used in the USB cable red, white, green, grey, black for pin numbers 1, 2, 3, 4 and 5.
Please take note of type-A & type-B have the same pinout diagram after arranging on the basis of similarity of shape.

Also check, USB OTG wiring diagram & USB C pin diagram and wiring color code

USB pin-out and its connector:

There are the female connectors for each of the male connectors in practical having the same pin-out as that of the male connector. The most common types of connectors are displayed in this image.

Table of mini and micro USB pin-out type-b & type-a:

Pin no. (look pinout figure)	Name	Wire code	Description
1	VCC	Red	+5V (dc power bus)
2	D-	White	Data- (device to host)
3	D+	Green	Data+ (host to device)
4	ID	N/A (dark blue / black)*	OTG-ID (generally not connected, if so then grounded/ according to the device need)
5	GND	Black	0V (dc ground)

The pin-out diagram for the micro USB type-B very similar to USB type-A except for the last two pins 4 and 5. Also, it is the same for micro USB type-a and micro USB type-b. The pin no.1 is +5V acts as a source to the device or source from the device.

Pin no.2 and pin no.3 are data lines (also called differential data lines because its application varies with the requirements).

The pin no. 4 (ID) is used for device identification especially in modern devices for OTG connections. For example, in as a smartphone OTG connector detection to connect a USB drive directly to the mobile phone. And the last pin no. 5 is a connection for ground signal which is pin no. 4 type USB-A through a wire.

How to find the USB wiring diagram manually?

Step1: First of all find out the type of USB connector used in the cable.

Step2: After the identification of the type of USB connector used on both ends, note down the pinout diagram of that particular USB type.

Step3: Note down all the color of the cable and where it is connected to the actual USB connector on a page. (rough sketch diagram will work)

Step4: Now connect connector pin and wires from the clutter according to the color code and pinout of that particular USB connector on the page using a pen, and your USB wiring diagram is ready.

List of standard USB connectors available commercially in the market which you can buy:

1) USB A male to USB B male.
2) USB A male to USB B female.
3) USB A male to mini USB B male.
4) USB A male to micro USB B male.
5) USB A male to USB C male.
6) USB A female to USB C male. (USB C OTG) and many more.

Micro USB pinout insight and USB-C:

The micro USB connector is most commonly used for charging mobile phones and various other portable devices like Bluetooth headset, Bluetooth speaker, Mini drones, Power Banks.
Some of the device manufacturers use their own standard of not connecting the data pin, as the cable is only made to work for charging purposes where only power bus/ wire is required to reduce the manufacturing cost.

You must have had thought of the question, why most of the devices use micro USB?

Most of the devices use micro USB due to the fact that it is compact than all of its precedents in shape and size. And after that, no other type of USB is able to replace it except USB-C ©.

USB-C is more complex micro USB-a than micro USB-b. The micro USB-C is simply called as USB-C.

The image and pinout of micro USB C are as follows:

Pin	Name	Pin	Name	Description
A1	GND	B12	GND	DC ground (+0V)
A2	TX1+	B11	TX2+	Super speed data transmit+ (host to device)
A3	TX1-	B10	TX2-	Super speed data transmit- (device to host)
A4	VDD	B9	VDD	DC power (+5V)
A5	CC1	B8	CC2	Power delivery communication line
A6	D+	B7	D+	speed data transmit+ (host to device)
A7	D-	B6	D-	speed data transmit- (device to host)
A8	SBU1	B5	SBU2	secondary bus
A9	VDD	B4	VDD	DC power (+5V)
A10	RX2-	B3	RX1-	Super speed data receive- (device to host)
A11	RX2+	B2	RX1+	Super speed data receive+ (host to device)
A12	GND	B1	GND	DC ground (+0V)

You can see a noticeable difference between USB C and micro USB. As you can observe that USB C can be inserted from any of the orientation. On the contrary, micro USB is direction oriented and we have to give attention while inserting it into the device.
In case if USB C port the Pin no. A1 to A12 is a mirror image of Pin no. B1 to B12. Thus, any functional allocation of pins from A shall be substituted to pins from B.
USB C has the advantage of orientation, on the other hand, it has the disadvantage of ring complex on the design level for the programmer and engineers.
Apart from this, micro USB comes in three variants (they have principally same micro USB pinout) as shown in the figure.
Type-C USB is a new connector system replacing the earlier micro USB. A lot of the new budget smartphones that are released every few weeks have micro USB C ports, they are becoming more popular in the smartphone and gadget category.
These micro USB C cables are available in different assemblies in different USB versions for various purposes, from USB C charging/ data cable to USB C OTG cable. You can check USB C wiring diagrams and internal wirings of USB 3.0/ 3.1.

The image and pinout of USB b super speed are as follows:

Pin no.	Name	Wire code	Description
1	VDD	Red	+5V (dc power source)
2	D-	White	D- (differential data pin) data negative
3	D+	Green	D+ (differential data pin) data positive
4	ID	N/C (dark blue / black)	OTG identification pin (generally not connected/ grounded)
5	GND	Black	0V (signal ground)
6	SSTx-	Blue	Superspeed transmit-
7	SSTx+	Yellow	Superspeed transmit+
8	GND	N/C (custom color pattern/ dark blue/ black)	Grounding
9	SSRx-	Purple	Superspeed receive-
10	SSRx+	Orange	Superspeed receive+

The USB b Superspeed pinout is the combination of USB b and 5 auxiliary pins which are predominantly used in high-speed External Hard Drives. The description section of the table above is self-explanatory.

These variants along with USB wiring diagram are decided by the usb.org, which is a ‘USB standards organization’ that maintains USB standards and improvise the USB technology and its applications.

i) micro a( USB 1.1 to 2): Previously in mobiles, now discontinued.
ii) micro b( USB 1.1 to 2): All current mobiles/ laptops/ desktop PC.
iii) micro b( USB 3.0): External hard drive/latest smartphone/ laptops.

Important things to consider about USB wiring diagram of cables:

Check that if you are USB cord has more than 4 wires then 5th one must be a bare/ open conductor. This open wire is generally surrounded to the four main wire from around. This arrangement is called as shielding.
To prevent external noise shielding is necessary. The most common practice is to ground shielding with the host and external device.
Shielding is generally avoided in low quality cheaply made USB cables, which is not in the favor of good quality USB cords. It is very important for the protection of data. Also for avoiding loss of data and hardware faults.

USB color code:

Very few people know that the USB connector has a color code. This color code is given to the USB on the basis of its standards defined by its organization. The colors are white, black, blue, red/ yellow.

White: It was introduced in 1996 (now outdated). It has a very low speed. The version it came from is USB 1.XX.

Black: It was in the market since the year 2000. It’s under version USB 2.XX. Its speed is up to 480 Mbps.

Blue: It published under the version USB 3.XX in 2008. Its maximum speed is 5 Gbps.

Red/Yellow: It is very same as USB3.XX with an upgraded feature of “sleep and charge”. This means that your device with this feature will not stop power supply even if the host device is turned off. This is very helpful for charging the mobile phone according to our convenience.

July 5 2021

10k Resistor Color Code- All Resistor Guide

smt Component ID

Resistor values are indicated by color-coded bands on a cylindrical looking shape, which can sometimes be difficult to interpret for someone who are not familiar with the resistor color code methodology. In this article, we will discuss the 10k resistor ohm resistor color code by looking at each band and step by step how to calculate the resistor’s value. Understanding resistor color codes is a knowledgeable skill for anyone from the electronics/ electrical field, and hope that this article will serve as a useful guide for beginners.

Image showing 10k resistor color code :

The 10k resistor color code is as shown in the image, it is Brown – Black – Orange – Gold. Importantly note that the color code of resistors does not depend on the power rating of resistor, the power rating of the resistor depends on its physical size and comes under standard wattage rating of 1/4 W,1/2W,1W,10W, etc.

Representational image Of 10k Ohm Resistor Color Code:

[Brown- Black- Orange- Gold]

Band	Color	Value (see table)
1st brown		1
2nd black		10
3rd orange		1000
4th gold		±5%
	1×10×1000=	10k±5%Ω

Link to 4 Band Resistor Color Code Calculator Tool for All Resistor values. Scroll down below to learn about the color code of all resistors and code chart.

Link to Online 5 Band Resistor Color Code Calculator Tool

Real Image Of 10k ohm resistor color code:

Also check, 10k smd resistor code
1k ohm resistor color code

Real value Of 10k ohm Resistor Color Code (with tolerance):

The digital multi-meter reads slightly more or less the value of the actual 10k resistor color code. This is because the 10k resistor color code last band tolerance value reads as a gold band which is 5%.

If you want to determine the value of any resistor then below are the steps to do it the easy way (color code of resistors):

Resistors are made from a mixture of carbon black or powdered graphite clay and resin binder the mixture is molded into the rods by compression or heating and then wire leads are fixed at the ends. Such registers are called carbon composition resistors.

The other types of resistors are carbon film resistors, metal film resistors, and wire-wound resistors. The color code of the resistor indicates the value of resistance and its percentage reliability for tolerance.

Check here the Current Calculator Ohms Law

The resistor has four colored bands or rings printed on the outer casing as shown in the figure:

But nowadays resistor also has five color band on its outer casing. The reason for this is the value of the register for high-end usage in modern industries and manufacturing.

The colored bands are read from left to right from the lead that has band close to it. The 1st and 2nd band represent (and 3rd in case of 5 band resistor) significant digits respectively. The 3rd band in the case of 4 band resistor band represents the multiplier (and 4th band in case of 5 band resistor represents the multiplier).

If the 4th band is absent the tolerance will be 20% (in case of 5 band resistor take it as 5th band).

Tolerance can be +- 2 % : 5 % : 10 % : 20 %

The significance digit of the resistor color is as shown in the table:

Colour	Significant Digit	SignificantDigits	Multiplier	Tolerance
	1st band	2nd band	3rd Band	4th Band
Black	0	0	10^0= 1	-
Brown	1	I	10^1= 10	-
Red	2	2	10^2 =100	-
Orange	3	3	10^3	-
Yellow	4	4	10^4	-
Green	5	5	10^5	-
Blue	6	6	10^6	-
Violet	7	7	10^7	-
Gray	8	8	10^8	-
White	9	9	10^9	-
Gold	-	-		+/-5%
Silver	-	-		+/-10%
No colour	-	-		+/-20%

Examples for 4 band color code:

1) If the bands on the body of the resistor are red, red, orange and gold, then the resistor value is 22 *10^3 and its tolerance is 5% that is 22 kΩ +- 5%

2) If the band on the body of the resistor is brown, black, Brown and silver then the resistor value is 10*10^1 Ω and its tolerance is + – 10% that is 100Ω + – 10%. This shows the value of resistance lies between 90Ω and 110 Ω.

3) The resistor of value 47*10^6 Ω+- 20% will have the color code yellow, violet, blue and 4th band will be absent.

Examples for 5 band color code:

1) If the bands on the body of the resistor are red, red, black, orange and gold then the resistor value is 220 *10^3 and its tolerance is 5% that is 220 kΩ+- 5%

2)The resistor of value 470*10^6 Ω+- 20% will have the color code yellow, violet, black, blue and 5th band will be absent.

Question for practice:

Q.The color band on the resistor is in the order grey, black, black then find its resistance and tolerance?
Ans. The answer is 81 + – 20%ohm.

March 10 2021

18650 Battery Specifications: Datasheet and Ratings

smt Blog

One of the most popular and commonly found cells in the battery pack or power supply are 18650 battery cells, here we have listed all the possible technical 18650 battery specifications that can be very useful in implementing any technical design of your product or gadgets.

What is an 18650 battery? and specifications.

The 18650 battery is a Li-ion battery named after its 18mm × 65mm cylindrical size (diameter × height). When compared to AA size, it’s height and diameter both are larger. They are not replacements for AA or AAA size cells.

The 18650 battery has a nominal voltage of 3.6v and has capacity between 1200mAh and 3600mAh (read as mili-Amp-hours).

The battery type 18650 are popular in rechargeable and high current draining devices considering its high-level capabilities like 250+ charge cycle and higher energy density. The 18650 Li-ion battery due to its adaptability all around can be found in various fields, say, electric cars/ scooters, power banks, utility gadgets such as emergency lamps, torchlight, etc.
Its safety property along with its high output current and energy capacity makes this battery popular among tech industries.

The 18650 battery specification includes its properties like the voltage, capacity, charge-discharge cycle, output current, output voltage and so on. This is a generalized specification of 18650 Li-ion battery, only properties marked with the remark of “Standard” are common to all 18650 batteries else not.

This is to note that other properties such as capacity charge discharge cycles and capacity (mAh) are subjected to independent technologies to increase capability values to the consumers by doing research and development. All the 18650 specs are listed in table with detail. You might like this article on simple 18650 battery charger circuit with auto cutoff.

Also check 21700 battery specs and properties.

18650 battery specification table:

Properties	Specifications	Remark
Component type	Battery/ Cell	Power supply
Battery type	Li-ion	Technology
Model No	18650	-
Size/ dimension	18 ✖ 65 mm	Standard (dd ✖ hh)
Voltage	3.7 volt	Nominal (std.)
Capacity	1200-3600mah	Per cell
Operating voltage	2.5-4.2 volt	Range (std)
Cutoff voltage	2 - 2.5 volts	Check respective datasheet
Weight	30gms to 55gms	Depends on capacity & technology
Charge density (Energy per cell)	1.5 - 11.5Wh	Energy
Charge discharge cycle	250 to 2000	In number ()
Optimum /Minimum charging time	2.5 hrs to 3.5 hrs	Per cell
Shelf life	36+ months	-
Charging method	CC and CV	-
Charging voltage	4.2v - 5v	5 volt max
Output current	-	Check C rating*
Charging current	-	Check C rating*
Internal resistance	-	High
Product variant	Regular and Flat top	-
Self discharge	6 - 10 %	Per month

Specs mention in above table is general, always check datasheet for accurate results.

Click for (Compressive comparison 18650 vs 21700 battery)

18650 battery size / dimension:

The Standard 18650 battery size is 18 ✖ 65mm.
The 18650 battery length is 65mm. The diameter of the 18650 battery is 18mm.

To be more precise, it has an approximate length of 65mm and an approximate diameter is 18mm but technically 18650 battery size is allowed with some tolerance in length and diameter. Thus you could find specification written as, (say) 18 ± 0.41mm ✖ 65 ± 0.25mm on datasheet and features of Li-ion cell.

Just remember 18 ✖ 65mm as a standard size, remaining things will be taken care of by designers and manufacturers of devices and batteries.

The size of the 18650 battery is allowed for the reason that, various gadgets or devices inhibit different locally developed technologies. That might not able to manufacture exact precise length & diameter of either batteries or battery holding space, to fit the device or 18650 Lithium battery respectively.

(check here how to charge 18650 battery with and without charger)

18650 battery data sheet:

The data sheet specification describes the technical parameters and standard tested output of each for the particular component or module.
Here we have discussed 18650 battery data sheet, on paper its a li-ion rechargeable cell supplied by various electronics manufacturing companies.

There are hundreds of 18650 battery data sheets available belonging to different model of 18650 batteries, there are lots of different models available varying in current rating and charge holding capacity. Also top manufacturing companies have their cell model with inbuilt overcharge protection and short circuit protection circuit to prevent damage to the cell as well as device in which it is used.

List of top 18650 battery manufacturing companies along with the data sheets of popular 18650 battery:

Samsung

Battery Model: Samsung 25R5 18650

Datasheet link: Samsung battery datasheet

Sony

Battery Model: Sony VTC6 18650 battery (US18650VTC6)

Datasheet link: Sony vtc6 datasheet

Battery Model: Sony VTC5 18650 Battery (US18650VTC5)

Datasheet link: Sony vtc5 datasheet

Battery Model : LG HG2 18650 Battery

Datasheet link: LG HG2 datasheet

Panasonic

Battery Model: Panasonic A 18650 Battery (NCR18650A)

Datasheet link: Panasonic A18650 datasheet

From their data sheet you can analyze and study what parameters are to be considered. All these parameter to be keep in mind before, while and after manufacturing, testing and launching the a final product in the market.

We have discussed these all 18650 circuits and how to use them here.

January 30 2021

How to Calculate Voltage Drop Across Resistor Step by Step

smt Basic Electronics

Understanding how to calculate voltage drop across a resistor is very fundamental for anyone who is into electronics or electrical engineering. In this step-by-step guide, we will break down the process, making it accessible and very simple even for beginners. By the end, you’ll have a solid grasp of this crucial concept, enabling you to analyze, solve and design circuits with confidence.

Before that let’s brush up the concept of Ohm’s law:

A common way to show the behavior of a circuit device is it’s characteristic.
This is a graph of the current “I” through the device as a function of applied voltage “V” across it. This device, the resistor, has the simple linear V– I characteristic shown in fig. above.
This linear relationship of the device is expressed by Ohm’s Law:
V = IR
Here, the constant of proportionality R, is known as the resistance of the device and is equal to the slope of the I–V characteristic. The unit of resistance is ohm, the symbol is Ω. Any device with a linear VI characteristic could be treat as resistive in nature.

What is the voltage drop across a resistor?

The voltage drop across a resistor is nothing but the voltage value across a resistor. Sometimes it is also called ‘voltage over the resistor’ or simply ‘Voltage drop’.
It is generally indicated as: ‘V(drop)‘ or ‘Vr’ or ‘Vd’
For multiple resistors, it is written as Vr1, Vr2, Vr3, and so on.

As we all know, a resistor is a device that offers resistance to the current flowing through it. Then, by applying Ohm’s law, the resistor will offer a voltage drop across a resistive device and it is given as:

V(drop) = I × R

where,

I = current through the resistor in (A) ampere
R = resistance in (Ω) ohms
V(drop) = voltage drop in (V) volts

How to calculate voltage drop over resistance step-wise :

Step1: Simplify the given circuit. If the circuit is full of resistors in series and parallel, then rearrange the resistors to make it appear simple connections. (check the practical example below)

Step2: Then, find the equivalent resistance.

For parallel use this formula: 1 / Req. = 1 / R1 + 1 / R2 …
And for series use this: Req. = R1 + R2 + . . .

Step3: Find the current through each resistor. (Current through the series resistor is same and current through the parallel resistors is different and depends on its value)

Step4: Apply the formula from Ohm’s law to calculate voltage drop, V=IR

One way is to check this link –> Voltage Drop Across Resistor Calculator online tool.

There is also another way to find the voltage drop, simply you can calculate it by using Voltage Divider Formula

The voltage across series circuit- Practical examples:

Case I:

If there is only one resistor in series with a battery or a power supply as shown in this circuit.

In this circuit, the voltage drop across the resistor is the same as that of power supply. This is because both the components have common potential points shared between them (point A & point B)

∴Vs = Vdrop = 5 volts (say)

Case II:

If there are two or more resistors in series with a battery as shown in this circuit.

In this circuit, we have to calculate the total current ‘I’ through the circuit.
I (total) = V(supply) / R(equivalent)

∴ I(total) = 5 / 30 =0.166 A

Then, the Voltage drop across R1 will be: Vr1 = I × R1
The voltage drop across R2 will be: Vr2 = I × R2
Also, voltage drop across Rn will be: Vrn = I × Rn

—> Vr1 =I × R1 = 0.166 × 10 =1.66 volts & Vr2 = I × R2 = 0.166 × 20 = 3.33 volts

The voltage across parallel resistors:

Case I:
There are two resistors in parallel with a battery or a power supply as shown in this circuit.

In this circuit, the voltage drop across these parallel resistors is the same as that of power supply.
This is because both the resistors have common potential points shared between them (point A & point B), so the voltage will be the same but the current will be different.

∴Vs = Vdrop = Vr1 = Vr2 = 5 volts (say)

Case II:
There is one resistor in series and two resistors with a power supply as shown in this circuit.

In this circuit, we need to calculate the current ‘I’ through each component.

i1 = I (total) = Is = V(supply) / R(equivalent)
Here, R(equivalent) = R1 + Rp,
Also, 1 / Rp = 1 / R2 + 1 / R3∴ Rp = 12Ω & R(equivalent) = 22Ω
i2 = i1 * (R3/(R2+R3))
i3 = i1 * (R2/(R2+R3))

The Voltage drop across R1 will be Vr1 = R1 * i1
A voltage drop across R2 will be Vr2 = R2 * i2
Voltage drop across R3 will be Vr3 = R2 * i3

Putting values we get,

Now, i1 = V(supply) / R(equivalent) = 5 /22 = 0.227 amps
∴ i1 = 0.227 A

Voltage drop across 10 ohm -> Vr1 = 10 * i1 = 10 × 0.227 volts
∴ Vr1 = 2.27 volts

Now, i2 = i1 * (R3/(R1+R2))
∴ i2 = 0.1362 A

Voltage drop across 20 ohm -> Vr2 = 20 * i2 = 20 × 0.1362 volts
∴ Vr2 = 2.724 volts

Now, i3 = i1 * (R2/(R1+R2))
∴ i3 =0.09 A

Voltage drop across 30 ohm -> Vr2 = 30 * i2 = 30 × 0.09 volts
∴ Vr3 = 2.7 volts

Method 2:

Find i1 = V(supply) / R(equivalent) = 0.227 A
Then,Voltage drop across R1 will be Vr1 = R1 * i1 = 10 × 0.227 = 2.27 volts
∴ Equivalent voltage at point ‘A’ will be equals to Veq = Va = Vs – Vr1
∴ Va = 5 – 2.27 = 2.73 volts
Therefore, we get equal potential value across R2 & R3.
Thus, Va = Vr2 = Vr3 = 2.73 volts

Method 3:

In this method, we use a digital multi-meter or you can say a voltmeter. All you need is to set the multi-meter to voltage mode.
Now using its 2 probes check the voltage across the required resistor by connecting probes across it. (in fig. voltmeter reading is for indications only)

Voila !! You got it.

This is the easiest way to find a voltage drop across resistor in any circuit.

December 19 2020

Where to buy electronic components online? Online Sources

smt Blog

Where to buy electronic components online?

Looking for a place to get your hands on electronic components? Well, the options are as diverse as the components themselves are. Whether you prefer wandering through a physical stops or navigating the digital online store, we’ve got you covered.

Finding a reliable electronic component store can be a bit of a quest these days. But, let’s not forget the convenience of online shopping. If you can’t locate a local store, or you’re just looking to save some time and don’t mind parting with a few extra pennies, there’s a whole world of electronic components waiting for you on the web. Where you might find some very cheap deals and low-cost options or some time be prepared to pay a little more because online prices tend to have a bit of a premium attached.

Lots of people searching now a day to buy electronic components store but very few are able to find a good one. This post will guide you through the electronic component stores near you as well as buying electronic components store online.

There are a lot of places to buy electronic components, but I myself prefer to buy components from the shop near me. Because I can get them without waiting much and even can test the working of expensive parts at the time of buying.

I only buy online components when a particular component is not available at the brick-and-mortar store. But as a matter of fact, only a few cities have these stores. So what to do? You can buy electronic components online through different websites in USA/ US and all over the world. If you are buying for the first time online then check out the following links and choose one to buy from.

Where to buy electronic components online in US?

Below are the online electronic components store to buy in United States/ US/ USA. Also check electronics component store near you:

1 Parts Express – www.parts-express.com/cat/electronic-parts/

2 DigiKey – www.digikey.com

3 Adafruit – www.adafruit.com

4 Amazon – www.amazon.com

5 Tayda Electronics – www.taydaelectronics.com

6 SparkFun – www.sparkfun.com

7 Allelectronics – www.allelectronics.com

Guide before buying electronics components online:

Buying electronics components online can be a convenient and cost-effective option, but it’s important to take certain precautions to ensure that you’re getting high-quality components that meet your needs. Here are some guidelines to follow before making a purchase:

Before buying from a new supplier, do your research to make sure that they are reputable in online market and have a good track record of providing high-quality components also good at customer service.
Make sure that the components you’re buying meet the specifications you need. Check the datasheet and other documentation to ensure that the components have the correct voltage rating, current rating, and power ratings, as well as any other relevant specifications.
Look around to compare prices from different suppliers. Keep in mind that the cheapest option may not always be the best, but it is always a good idea to compare prices to ensure that you’re getting a good deal.
Make sure to check the shipping and handling cost and time, and also the supplier’s policy on lost or damaged items, because sometimes, buying cheaper components online can cost you more than due to shipping costs.
Be aware of counterfeit components that are often sold online particularly Chinese, it’s important to buy from reputable online store and look for signs of authenticity such as serial numbers.
Read reviews online of that supplier to get an idea of their experience and the quality of the components.

Where to buy electronic components online in UK?

Below are the online electronic components store to buy in United Kingdom/ UK:

1 RS electronics: https://uk.rs-online.com

2 Kitronik – https://www.kitronik.co.uk

3 Hobbytronics – www.hobbytronics.co.uk

4 Quasar Electronics – www.quasarelectronics.co.uk

5 Rapid Electronics – www.rapidonline.com

6 Spiratronics – www.spiratronics.com

7 Bitsbox – www.bitsbox.co.uk

8 Mouser – https://www.mouser.co.uk

Where to buy electronic components internationally?

Below are the online electronic components store to buy internationally/ worldwide:

1 RS electronics – https://www.rs-online.com

2 eBay – www.ebay.com

3 Farnell – www.farnell.com

4 Arrow – www.arrow.com

5 Mouser – www.mouser.com

Above is the list of websites that you can check out to buy from, as of human psychology one tends to buy from the same store again and again and you might be one of them who love to buy from your favorite stores.

If some components are not available in that store you can buy from your second preferred online electronics component Store.

Tips before buying electronics components online:

Make the list of components to buy.
Also, write down the component and its value/ specification on paper before buying. For example,write down Resistor value and number of resistors of that value to buy, and same for capacitor and modules. Last but not the least do buy the components if you need in the very near future so that you need not to buy more frequently saving on time and money.
Delivery charges can be reduced or omitted if you buy electronic components having total cost more than the threshold cost mention on the e-commerce site. Almost all online stores have this policy.

October 2 2020

12v to 6v converter- Best 5 circuit collection

smt Circuits

Schematics of the simple 12V to 6V converter circuits are discussed below. These linear DC to DC converter circuits can be used to convert all types of 12V power supply to a 6V power supply.

Below 12v to 6v reducer can be useful in case you want to replace your 6v battery with a 12 volt battery or a 12 dc power supply adaptor.

How to reduce voltage from 12v to 6v?

Linear Regulator circuit using LM7806 and LM317 helps to step down or reduce 12v battery potential to 6v so as to use it with any IC’s that is needed to be powered with this much potential. It is recommended to use reliable linear regulator /power converters for efficient function and to avoid accidental circuit failure.

12v to 6v converter with LM7806:

LM7806 is a fixed voltage regulator IC that regulates the input voltage used in the electrical and electronic circuit.

A step down 12v to 6v with IC LM7806 is constructed as shown in the schematic below. It is generally used for mid current application from few miliapms and up to 2 Amps.

Tips:
It is recommended to connect the input capacitor ‘Cin’ and an output capacitor ‘Co’ to the IC 7806 according to the datasheet. The heat sink must be connected to this regulator IC so to prevent it from heat damaging.

There is a possibility of IC destruction if the heat-sink is not connected. The i/p to o/p voltage difference should be maintained at 2Volts. This is called “drop out voltage” in technical terms.

Components required:
A 12v power source, 10uF capacitor, 0.1uF capacitor, IC LM7806, a Heat-sink, wires or connectors.

Working:

The IC is designed so that it can be modified to work as short circuit protection for your critical circuits. It can also be used as a current regulator in the circuit.

LM7806 is an IC of LM78xx series all the ICs in this series are made for different fixed output voltages, but it can be modified to be operated as variable voltage regulator. These types of ICs are known as Linear regulator ICs. Even these ICs can be operated without any external components, that reduces the circuit cost.

LM7806 a linear transformer IC. The digits ‘xx‘ represents the value of the DC output volts, in this 7806 IC gives 6V DC as the digit ‘xx‘ in the last, reads as (06). The output accuracy ranges between 2% to 4%.

Pin number 1 is the input pin, Pin 2 is the ground pin, Pin 3 is the output pin when seen as printed area facing the person.

(values of capacitors can be different as per the area of application)

LM317 12v to 6v converter:

A 12v to 6v dc converter can be made with a popular IC LM317 voltage regulator as this IC gives adjustable output DC voltage with some changes in the external circuit. It is useful for medium to high current circuits (1 Ampere to 1.5 ampere+)

Generally, LM317 is found at variable power supply circuits that give regulated voltage (1.25V to 37V) on changing the voltage on pin no.1. Here, the voltage divider circuit is used with LM317 gives a fixed o/p of 9v.

Important:
It is suggested to add an input capacitor Cin and the o/p capacitor Co (without this capacitor it works but regulation could be affected). A heat-sink is required to cooling the IC from the heat generated also prevents it from damaging.

The dropout voltage of this IC is very low as compared to other ICs, and thus the i/p voltage must be at least 1.5V or larger than the required output voltage for this IC to be working.

Components required:
A 12v power supply, a 1.8k ohm resistor, 6.8 kilo-ohm resistor, 10uF capacitor, 1.0uF capacitor, IC LM317 attached with the heat sink.

Working:
The LM317 is an versatile IC, with the feature of adjustable voltage regulation & capable of supplying regulated voltage….

(for more detail on LM317 regulator and its working go to this link)

The formula for output voltage is given as:

This the formula for the output voltage of 12v to 6v reducer using LM317. It gives an approximately required output when R2 and R1 are chosen to equate the formula. Consider the value of resistors in kilo-ohms so as to reduce power consumption.

Also, check the 12v to 6v regulator using the transistor below, this circuit is almost obsolete as there is various single package IC available to buy and use. A very convenient and compact circuit can be implemented with modern solutions.

12v to 6v converter using resistors as a voltage divider:

The schematic below shown below is the 12v to 6v reducer for a small current drawing circuit, or to take reference voltage in comparator circuit or circuit for indicator LED.

You can drive few LEDs in series across the resistor R2 (1.2k) if you are using a 12volt battery in the input end. You can take the output from resistor R1.

This type of circuit is not that popular among the makers because of low current, thus not recommended for use in projects.

Components required:

One 12v battery/ power source, 1.2k-ohm resistor, some wires.

It is a simple voltage-divider circuit. You can get the required voltage with this formula:

Where ‘Vo’ is the DC output voltage. ‘Vin’ is the unregulated voltage. You need to pick a resistor value either R1 or R2 (also depends on load impedance) and solve for other. Then choose the standard value of the obtained resistor nearest to it.

12v to 6v converter using zener diode:

The circuit 12v to 6v reducer shown below is by using a zener voltage regulator, it can be used for (1-800mA) medium current drawing circuit eg. LED indicators, in over-voltage protection, in reference to voltage circuit.

You can use this DC to DC 12v to 6v converter circuit with any other circuit by taking voltage across the 6.2v zener diode. You will get ~6.2V at the output.
(Please note that it is approx 6 volts, not exact 6 volts, use above circuits for exact 6volts, most of the devices can handle the tolerance of 2-4{42041a7992ac3be9e9e29c856254fb498d8c7935d7cf8512da6802e8688e734a} thus this can also work)

Important:
The load must be connected to the output end of the regulator to prevent the zener from being burnt.
A series resistor Rs =10 ohm is a current limiting resistor and when high current is drawn it will go through it, thus a 3- watt resistor is necessary.

Components required:
12v source, 10-ohm resistor (watt rating is important when a circuit is drawing more current than few milliamps), 6.2V zener diode (1W/3W/ 5W) higher wattage is recommended, some wires or connectors.

Working:
This is the general schematics of the zener diode as a voltage regulator.

Design a 6.2 volt zener voltage regulator from a 12volt dc power supply. The maximum power rating …

For detail calculation and formulae search for 12v to 6v step down converter article from search box in the menu.

12v to 9v converter using transistor:

loading …..

September 29 2020

100k ohm resistor color code- 4 band

smt Component ID

100k ohm resistor color code with 5{42041a7992ac3be9e9e29c856254fb498d8c7935d7cf8512da6802e8688e734a} tolerance is as shown below:

You can calculate the resistance of any resistor using this online 4 Band Resistor Color Code Calculator Tool

100k ohm resistor color code:

Brown, Black, Yellow, Gold

Band	Color	Value
1st Brown		1 (1st digit)
2nd Black		0 (2nd digit)
3rd Yellow		10000 multiplier
4th Gold		5% tolerence
	practical value can be found using a multi-meter	100K±5% ohms is its theoretical value.

Actual value of 100k Ohm resistor is calculated as:

1st band= Brown= 1 (1st digit)

2nd band= Black= 0 (2nd digit)

3rd band= Yellow= 4(multiplier)= 10000

4th band= Gold= ±5{42041a7992ac3be9e9e29c856254fb498d8c7935d7cf8512da6802e8688e734a} (tolerance)

Therefore, 10×1000000±5{42041a7992ac3be9e9e29c856254fb498d8c7935d7cf8512da6802e8688e734a} ==> 1000000Ω ==> 100KΩ

And tolerance considered as ==> 5{42041a7992ac3be9e9e29c856254fb498d8c7935d7cf8512da6802e8688e734a} of 100K ==>5000Ω

Final assumed value of 100KΩ resistor is between 95 kΩ to 105 kΩ

Other methods:

First remove the resistor from PCB then test it with a digital multi-meter in resistance mode and note down its value. It needs to be separated from PCB so as to avoid the equivalent parallel resistance from around resistors in the circuit.
So, 100 Kilo-Ohm resistor color code is brown-black-yellow-gold

Also, check 1mega ohm/ 1M ohm resistor color code

September 17 2020

Red wire ceiling fan wiring- 7 diagrams for wiring a fan

smt Blog

Wiring a ceiling fan seems to be a demanding job but it’s not that hard as it looks. SoManyTech brings you the red wire ‘ceiling fan wiring’. And switching circuit along with color code of wire in different regional wire codes (country-specific).

Apart from this, different company’s ceiling fan has distinct color wires depending on what type of motor used in the fan some time that does not match with household wiring color.

Different types of fans available in the market come with different number of wires:

Simple fan with 2 wire
Fan with 3 wires (as seen from fan side with capacitor)
4 wire fan with inbuilt LED light

Considering all the above facts, we have created a ceiling fan wiring diagram guide for ease of installation process. Based on countries and their wiring code there are two major classifications.

Table of wiring code in different countries:

Wire	USA	UK, India, EU, Australia
Line 1 (Live wire)	White	Brown(new)/ Red (old)
Line 2 (Live wire)	Red	Black (new)/ Yellow (old)
Line 3 (Live wire)	Black	Grey(new)/ Blue(old)
Neutral	Blue	Blue(new)/ Black(old)
Ground	Green/ Yellow	Green (striped yellow-green)

Also check, wiring a 4 way switch full guide.

[A] Ceiling Fan wiring diagram for US/ Canada

While working with fan connections make sure you connect wire as shown or according to the diagram on the user-manual.

Important: You can interchange or replace the color of live wire if you have multiple devices connected though the same path or at the same place.

1) Red wire ceiling fan wiring diagram:

2) Black wire ceiling fan wiring with light:

3) Two wired Red wire ceiling fan wiring diagram:

4) Two wired Black wire ceiling fan wiring diagram:

[B] Fan wiring diagram for India/ UK/ Europe/ Australia

1) According to 0ld standard red wire in connection:

2) Ceiling fan wiring 4 wire connection (new standard):

3) Red wire ceiling fan wiring diagram 3-wire (old standard):

4) Two wired Black wire ceiling fan wiring diagram (new standard):

Ceiling Fan Capacitor Connection/ internal wiring of a fan:

Take a look at ceiling fan capacitor connection wiring, this color is not the same for all fan manufacturing company. Therefore, we have the method to determine it with a digital Multi-meter.

( look the capacitor connection, how the color of wire is used in fan’s output. Looking at them, we cannot guess the purpose of wire until and unless the circuit diagram is provided with the fan itself. The main reason behind the confusion for connections is this only.)

Where to connect the Live wire and Neutral in the 3 wire output system in Fan?

Just follow the below steps and get the wiring solution of a fan.

Step0: Turn off the power supply of that particular room in which you are working.

Step1: Set your digital multi-meter to resistance mode.

Step2: Now check the resistance between three wire taking two wires at once. (must remove capacitor connections and other connections to the fan)

Step3: Along with it, mark down the resistance between two wires with their respective colors.

Step4: You will get two values of resistance one is higher (running coil W1) another is lower (starter coil winding W2).
So you have to connect the live wire and neutral wire between two-wires having higher resistance (between points 1 & 3) of the output of the fan.

Step5: Connect the one wire of a capacitor to the neutral-wire (point 3) and another wire of capacitor is connected to the unconnected wire (point 2) of the fan’s output (in series with lower resistance coil/ starter coil)

Step6: Now insulate all the bare wire connection with the insulating tape. And turn on the fan.

Required tools:

Basic tools such as a ladder,
Voltage Tester, Screwdriver,
Insulating tape

Precautions:

Turn OFF the FAN (temporary cutoff of room power is recommended)
Do not connect wire merely on the basis of prediction.

June 9 2020

7 Simple Power Bank circuits using TP4056 & 18650 battery

smt Circuits

This article will take you through all the aspects of a power bank circuit at home, with an in-depth steps to building power bank along with different modules, circuit board, connection diagram, and external case to use with it.

Nowadays it has become very impossible not to have a portable charger, alternate power source to recharge your smart phone as becoming very hard to maintain a phone’s battery for a day without charging due to the heavy usage of smart phones in day-to-day life. The best way is to carry a mobile charging source i.e a power bank.

If your old power bank got damage or not working then this article could be helpful to you in repairing your old power bank at a very low cost even without the need to buy a new one. The best way is to simply DIY yourself a new one or repair the non-working power bank.
Also check Simplest 18650 Battery Charger circuit with auto cutoff DIY

Block diagram of a typical power bank circuit:

Block diagram of a power bank primarily consist of three main functions as shown in the above image: A charge controller, 5v boost converter, Li-ion battery.

a) Battery charge controller circuit:

The function of the battery charge controller circuit is to control the state of charge of any battery according to its capacity and rated voltage. Other than this, it also helps battery against overcharge.
Here, a lithium-ion charger module which is based on IC TP4056/ TP4054 is used and a micro USB port to charge the battery is present.

The battery charge controller module TP4056 in the image is designed keeping in mind the highly critical li-ion batteries and reduced manufacturing time and cost by using SMD components.

b) A 5-volt boost converter circuit:

The function of the 5-volt DC-DC boost converter circuit is to convert the lower voltage of a battery to 5v regulated DC. Here, it converts 3-3.7 v DC obtained from LI-ion batteries (std. 3.7 volt is rated) to steady 5volts so that our mobile charges at standard voltage normally.

A DC-DC boost converter comes with a female USB port to connect a USB cable from our mobile phone to it. The boost converter module works on the principle of (PFM) Pulse Frequency Modulation.

Check this interesting video below on working of power bank:

c) Rechargeable lithium-ion batteries:

Everybody knows the function of batteries, the only thing to consider is to use rechargeable batteries aiming at re-usability. The battery pack in power bank is a combination of 3.7 volt li cells connected in parallel.
The 18650 cells are the most commonly used Li-ion cells in the market these days. Some power bank brands use flat li-ion cells to make it thin and compact.

You can read the 18650 battery specification here.

d) Battery level display unit (optional):

The display unit may be or may not be present in a power bank as it adds the extra cost to the product company prefer to eliminate it in low-end products. The battery level display unit has two functions, first is to show the state of charge in percentage (%) and second is to indicate charging of both mobile phone and power bank.

Working: The power bank is a simple power backup device for your iPhone which is portable/ handy instantly to charge a phone when the battery is low.

The charge controller charges the battery to its appropriate level and protects it from damage caused due to overcharging. Our mobile phone’s battery needs 5volt dc at 1 A or 2 A but cells inside the p-bank have the maximum output voltage of 3.7 volts. Thus a boost converter boosts up the level to 5Volts which is required to charge a phone. The modules come with an input port (micro USB) for charger and output ports (USB female) for mobile charging.

Watch how power bank circuits and controllers work at the end of this post.

Power Bank circuit using module TP-4056 and a 5v boost converter:

In this circuit, a total of 3 lithium-ion cells are used. All batteries are connected in parallel with each other connection to increase backup of a power bank.

As we know that in parallel connection of batteries voltage remains the same but current capacity is increased. So for increasing the current all batteries must be connected in a parallel configuration.

Connection:
Assemble all li-ion cells 18560 in a parallel configuration and put it into a casing or just tape it. Means solder positive terminal of one cell to the positive terminal of other cell and negative terminal to the negative terminal. Now we have two wires one is red positive and black negative wire. Connect the black wire to negative of 5v boost converter module and to controller module TP4056. Similarly, connect positive terminal from battery to positive terminal of both the modules.

Keep in mind, the marking on the module + and – accordingly connect wires. You can put all these components in an assembly case. Its done DIY power bank is ready to use, make sure you charge it completely before using it for 1st time.

18650 battery charger circuit (how to charge 18650 battery)

Power Bank circuit using dual USB output port module:

In this circuit we will use all in one module, it comes with dual USB 5volt 1A/ 2A rating. Various modules for this function from the different manufacturers are available with slight change in specification.

Connection:
Assemble all 18560 rechargeable cells in a parallel configuration as mentioned above. Means solder +ve terminal of one cell to +ive terminal of other cell and a negative terminal of one cell to negative terminal of other. Connect the black wire from battery to negative terminal of this dual USB out power bank module. Similarly, connect +ive terminal from battery to +ive terminal these modules.

There are markings on the module as + and – symbols make sure you follow the circuit diagram

Power Bank circuit using a single USB output port compact module:

In this circuit we will use a compact module, it comes with a USB 5volt 1A rating. It is used where only one USB output is sufficient for use, also saves space as it is very compact. The major advantage for this module is that it restricts simultaneous charging and discharging of power bank that prevents its board from damage.

Connection:
Assemble all li-ion cells 18560 in a parallel mode, just solder positive terminal all cell to red wire and negative terminal of all cells to the black wire. These two wires, one is red positive and black negative wire are connected to the positive and negative of the charger controller module respectively. The marking on the module may be B+ and B- note that while connecting.

Using this circuit you can repair your power bank, just remove the batteries from an old p-bank and use it with third-party module. (depends on what part of old p-bank is faulty)

Solar power Bank circuit using TP 4056 and a 5v boost converter module:

What if you don’t have to recharge your power bank more frequently? Here is a twist, make is solar powered power bank. An extra component is needed i.e a solar panel module of 5volt 500mA/ 1000mA. Buy it and follow the connection diagram below, go through the power bank internal circuit.

Connection:
As we know that all li-ion cells 18560 must in parallel connection to use it with the modules to utilize battery capacity. Take any two-color wire to join positive terminal with one wire and -I’ve with others wore and mark it down for further wiring.

On controller module TP4056 circuit board locates +N and -N terminal. On that terminal connect positive terminal from battery to +N terminal of a module and -ve terminal from battery to -N terminal on the circuit board. Make sure the symbol on the module + and – , never interconnect wires because it will burn the circuit board. Remaining wiring is easy as shown in the image. Assemble it smartly to look good and voila! it’s done. Now use your power-bank whenever required and feed it sunlight to recharge it.

May 3 2020

Voltage Divider Rule- Formula detail Explanation

smt Basic Electronics

Voltage divider rule is one of the most common concept in electronic circuit design. So today we will be discussing in detail the voltage divider formula from where it comes from where the formula is derived along with some practical example. Also mentioned how to design voltage divider circuit for the required output.

While going though electronics basics we face a lots of difficulties learning the formulas, the rules and steps to implement them. But, below topics covered the easy method to learn formulae along with the tricks to remember it.

What is voltage divider rule?

Voltage divider rule is also called as potential divider rule or potential division rule or voltage division rule.
In short, it is assigned as VDR.

Voltage divider rules give the insight of the schematic circuit diagram and applicable formula and its derivation to help with different voltage requirement in the circuit designing.

Voltage divider definition :

> It is defined as the circuit which is used to reduce the large value of the voltage to the smaller value.
> Voltage divider circuit gives the required output voltage as a fraction of input voltage which can be manipulated using formula.
> A voltage divider circuit is a circuit that divides the single voltage value to the multiple output values.

The Voltage Divider is Passive in nature (as it has no active elements) and behavior is Linear (as output is linearly proportional to input)

Voltage divider schematics circuit:

Fig(a), Fig(b) & Fig(c) are voltage divider circuit diagrams.

The image showing three circuits below, they might appear different but fundamentally the same. They are only one circuit with different arrangements and source symbol. Simplifying them you will end up concluding that they are same in electrical rules.

Analysis and Voltage Divider Rule formula:

Figure showing a Basic diagram of voltage divider circuit which has two resistors. This is the basic circuit diagram that shows the VDR and its formula. This is very basic circuit and the formula is used for the calculating the output voltage allover while analyzing the circuits.

There voltage divider rule fits in the same concept as Voltage Drop Across Resistor check here!

Voltage divider rule proof and derivation:

Here, voltage supply is V is connected in series with resistor r1 and r2.

And current ‘i’ is flowing though them causing a voltage drop of v1 across r1 and voltage drop of v2 across r2.
As this is a closed-loop, the current flowing though it will be the same.

For deriving output voltage formulae we need to apply Ohms law across each resistor and the putting the values in equation obtained by KCL (Kirchhoff’s Current Law) as shown below step by step:

According to Ohm’s law we get,
v1 = i☓r1 ———-(I)
v2 = i☓r2 ———–(II)

Applying KVL in the above circuit
V – v1 – v2 =0
ie, V = v1 + v2

By putting the value of v1 & v2 in above equation,
we get,
V = i☓r1 + i☓r2
∴ V= i☓( r1 + r2)

Hence,
i =V / (r1+ r2)

Substituting the value of “i” in (I) and (II)
we get,
v1 = r1☓(V / (r1+ r2))
v2 = r2☓(V / (r1+ r2))

(by adjusting the variables)
Also,
v1 = V☓(r1 / (r1+ r2))
v2 = V☓(r2 / (r1+ r2)) →(note: v2 = Vout) →(III)

(by adjusting the variables for the conditions where we need to find the values of resistors)
Again,
r1 = (v1☓(r1+ r2)) / V
r2 = (v2☓(r1+ r2)) / V

[note: the above formula is very important and has its applications in designing voltage divider circuit]

To be Concluded :

From equation →(III) we can say that the output voltage is equal to a voltage drop across output resistor (the resistor across which we are taking output)
(check the circuit with 3 resistor in series you will get the point)
The values of the resistor at denominator is nothing but the equivalent resistor of r1 and r2, it can be r1+r2+r3+…+rn, where n number of resistors.

Figure showing voltage divider with 3 resister and its equivalents:

In this circuit (as per the above conclusion from derivations):

→As in Fig. 1 Vout1 is the voltage across resistor R2 and R3

∴equivalent series resistanceR2 and R3 are taken.

→In the Fig. 1, Vout2 is the voltage across resistor R3 only.
Therefore, the equivalent series resistance R3 is taken.

For Fig. 1(a)

For Fig. 1(b)

The practical example of voltage divider circuit (VDR):

Q. Design a voltage divider to give the output voltage of 1.5 volts for designing an amplifier biasing. The given source voltage is 5V.

Ans.
Given→Vo= 1.5V & Vin= 5V
from eq→(III) or simplified formula(look for 1st image of the post)

we have, Vo= Vin.(R2/(R1+R2))

Assuming, R1= 1KΩ
and putting all the values in the formula,
1.5= 5.(R2/(1K+R2))
We get, R2= 0.428KΩ

Q. Design a voltage divider to give the different output voltage of 3 volt and 6 volts for the comparator, given that the input voltage source is having a potential difference of 9 volts.

Ans.
As equal resistor in series offers Equal voltage drop across each resistor.
∴ according to the question,

Vin= 9 Volts, Vout1= 6Volts and Vout2= 3Volts

From this, we can conclude that the smallest output is 3volts and another required output voltage is 6 volts.
Then, we can use three resistor of same values.(say 1kΩ)
∴ R1= R2= R3 = 1kΩ design is completed.

Q. Design a voltage divider to give the output voltage equal to half of the input. The given source voltage is 12V.

Ans.
Given→Vo= 1/2Vin & Vin= 12V

using the simplified formula:
we have, Vo= Vin.(R2/(R1+R2))

Assuming, R1= 10KΩ
put all the values in the formula ∴ 6= 12.(R2/(10K+R2))
We get, R2= 10KΩ

Now design the circuit with these components!!

Q. Can we apply voltage divider rule in parallel circuits?

Ans.
No you cannot apply voltage divider rule in a parallel circuit as it is only applicable to resistors in series. Only the reason that VDR is the modification of Ohm’s law.

Q. Do voltage divider rule only applicable to resistors?

Ans.
No, It can be applied to any passive element like capacitor and inductor. The only thing you have to assume is their impedance (Z).
Instead of the resistor in voltage divider rule, you need to use impedance along with the modified formula of impedance equations.
Zr for a resistor, Zc for a capacitor, Zl for an inductor.

Application of voltage divider rule and circuit :

1) It is used as a biasing circuit in the BJT amplifier.

2) Feedback Circuit in operational amplifier uses the voltage divider rule for driving the input and control the voltage gain.

3) It is the important circuit in comparator that is used for comparing different voltages whether the particular voltage is greater or smaller than the reference voltage.

4) The Logic Level Shifting use the voltage divider formula.

Something important to note:

When the resistor R1 and R2 are the same, means, it is of the same value then the output voltage is exactly the half (50%) of the original input.
Also, this circuit implies that it is useful where we don’t have a lower voltage source.
It can be used as a substitute for the transformer ( only and only if the load is having large resistive impedance, we must use high wattage resistors say 3W/5W, it is very less practically used as it possesses the risk of electric shock)
You noticed electrical line tester (live wire tester), it is nothing but voltage divider with resistor R1 and resistor R2 which is replaced with a high impedance low current consuming indicator light.

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