Automatic simple 12V 100mA NiCd Battery Charger circuit

Today we are going to learn how to make a very cheap NiCd battery charger with overvoltage protection or control circuit. This circuit is very much simple and specifically designed for 12V NiCd battery. The charger have current and voltage control at the same time.

Its charging current is around 100mA but we can change it using the formula : (Vd1 - 0.7) / R2 ; where Vd1 is voltage of zener diode D1.

Its Cutoff voltage is limited to Vd2 - 0.7 ; where Vd2 is voltage of zener diode D2

Part List:-

R1 - 2.7 kilo ohms 1/4watt

R2 - 56 ohms 1Watt

D1 - 1N4735A or any 6.2V zener diode

D2 - 1N5244B or any 6.2V zener diode

D3 - 1N4001 or similar diode

Q1 - 9013, 2N2222 or similar NPN transistor

Q2 - 2N3440 or similar NPN transistor

Simply solder the above circuit and enjoy simple 12v 100 mA or change it.

For any further querry please ask them in comment section. I wil be happy to help.

Simplest 5V Transformerless Power Supply Circuit

How to make Simplest Transformerless power supply for low current and low voltage application(5volt 150mAmp) using a IC-LR645

By:Alok kumar

Some of the followers of this blog have requested to post a simple low current and low voltage i.e 5volt & 100mAmp. So today i am going to post an transformerless power supply which is not only easy to construct but also very cheap and small or compact electronic circuit. This electronic circuit can be used to for various purpose like charging small li-ion batteries e.t.c. In this circuit we are going to use IC-LR645 which can control any voltage between 24 and 270 V AC and produces DC voltages below 15 volts at the output, which becomes ideally suitable for operating condition.

The great thing about this circuit is that it does not include or incorporate any bulky transformer but it also dont uses high voltage polar capacitors here. So no worries about surge current and we don't need crowbar protection circuit here.