Thursday, April 5, 2018

Lithium Battery charger Using TP4056.

If you are looking to charge Single Cell lithium Ion/Poly and don't want to make complex circuit and fiddle with it you can simply use a Battery charging module that uses TP4056.

A few important characteristics:

1. TP4056 is a linear Lithium battery charger that can put out a maximum of 1A charge current.

2. It does have a soft start feature that reduces the inrush current.

3. Can be easily powered via USB.
4. Single Resistor to control the charge current. Programmable from 130mA to 1000mA.
5. Two status Indicator LED for easy situation understanding and troubleshooting.
6. Can be bought with Protection circuitry built in.

Let's take a look at the board:


Wiring up this board can't be any easier. Just connecting the B+ to positive terminal of the cell and B- to the negative terminal of the cell is all you need to do.

Selection of Charging Current:

It is a good rule of thumb to charge at 0.5C that means if you have 2000mAh rated cell, charge it at 1000mA rate. Although lithium cells can be safely charged to 1C if it is not too hot yet 0.5C should be a good balance between pushing the cell too much and time required to charge it.

Datasheet contains more valuable information like what is meant by the LED indicators and what should be the proper resistor for certain charge current.

That is pretty much it for the post, for datasheet and other resources visit the links below.

1. Datasheet Bank.
2. Visit My full Blog for more circuit diagrams and other interesting stuffs.

Tuesday, April 3, 2018

Why Bangladesh needs Nuclear Power Plant

  1. Bangladesh is running low in it’s Natural Gas reserve. Already good amount of Gas(LPG) has to be imported to meet the demand and with time it will only increase. The way households in Bangladesh use gas it is not going to last long. Moreover Gas Transmission Titas is corrupted to the bone, they sold huge amount of Gas to industries taking backdoor money from those industries so Bangladesh needs an alternative source of power. With Nuclear plant household can rely on Electricity to cook as excess electricity should theoretically make it cheaper. This will offload the pressure on Gas.
  2. Vehicles that run on Natural Gas can be replaced with electrical one as with cheaper and more available electricity those vehicles will be able to top themselves up without significant disturbance on the Line.
  3. Fertilizer factories will still require Natural Gas so offload the pressure on them is important. If Bangladesh runs out of Gas it will have to import those fertilizers as well.

Monday, April 2, 2018

Ceiling Fan Regulator or Incandescent Lamp Dimmer Circuit

Good Evening.
Let's look at a Ceiling Fan regulator or an Incandescent lamp dimmer circuit and see how we can make one by ourself.

Components Required:


1 500KΩ Variable
1 4.7KΩ


1 0.1µF 100V Ceramic.


1 DB3


1 MAC97A8


This circuit will be in series with the load that needs to be controlled.

Working Principle:

In terms of how this circuit works, it is pretty complex so I'm not gonna go into much details here but I will talk about those components and how they work in some other post. These components are a TRIAC and a DIAC. To explain the circuit simply what it does is change the normal sine wave that we get from main line in order to provide less power to the appliance thus dimming the lamp or slowing down the ceiling fan. However as it distorts the sine wave many appliance like LED lamps won't work with this type of Dimmer. 0.1µF capacitor is used for triggering which first charges via the Variable Resistor. Higher resistance means more time will be required to charge up the capacitor.


1. This circuit runs on 220V AC main line. To avoid electric shock do not touch any part of it during operation.
2. To modify any part of the circuit make sure to disconnect it completely from main line.


1. Datasheet bank.
2. Visit My Full Blog.

High Quality Headphone Amplifier with LM4880

Good afternoon.
Today we will be looking at a high quality headphone amplifier that can run on USB power and only has a few external component.

Components required:


1 0.1µF Ceramic.
3 1µF Ceramic.
1 10µF Electrolytic.

2 470µF Electrolytic.


5 20kΩ 

Integrated Circuit:

1 LM4880


For USB power.

For Audio Input and Output.


Output power:

85mW into 32Ω headphones.
200mW into 8Ω headphones.


1. Place the 0.1µF capacitor as close to the LM4880 possible.
2. Value of output capacitor has been calculated using 32Ω load, for 8Ω load use 1000µF.
3. Use a power source that is noise free and stable.
4. Good quality capacitors should be used.