Category Archives: Power Electronics



1 – 9V Variable Desktop Power Supply

Here the variable desktop power supply which will convert a high input voltage (12V) from the SMPS / PSU of a desktop computer into small output voltage (1.25 to 9 volts). This converter will be very beneficial for electronics hobbyists. An adjustable three-pin voltage regulator chip LM317T (IC1) is applied right here to deliver the… Read More »

Simple Mobile Phone Battery Charger

The following diagram is a simple mobile phone battery charger circuit. The design is simple, easy to build and inexpensive. It use LM78xx regulator to make regulated and stable output voltage. Mobile phone chargers offered in the marketplace are quite expensive. The circuit shown right here shows up as a low-cost option to charge cell… Read More »

Power Supply Failure Alarm

This is the ‘special’ circuit design of power supply failure alarm. The vast majority of the power supply failure alarm / indicator circuits require a independent power supply for themselves. However the alarm circuit introduced right here requires no extra supply power source. It utilizes an electrolytic capacitor to hold sufficient charge, to supply power… Read More »

4-Output Stage (5V/6V/9V/12V) Stabilized DC Power Supply

This is definitely an effective 4-output stage stabilized DC power supply unit for testing electronic circuits. It delivers very well regulated and stabilised output, that is important for most electronic circuits to provide good results. The circuit gives you an audio-visual indication if there is a short circuit in the PCB under test, so the… Read More »

Automatic Switching-on Emergency Light

Automatic Switching-on Emergency Light The schematic diagram shown right here is the automatic switching-on emergency light circuit which is controlled using IC. The most important capabilities of this circuit are: automatic switching-on of the light on main power failure and battery charger with overcharge protection. When mains electrical power is absent, relay RL2 is in… Read More »

Report: DC/AC Pure Sine Wave Inverter

Here the project report of DC/AC pure sine wave inverter. This report focuses on DC to AC electrical power inverters, which aim to efficiently transform a DC power source to a high voltage AC supply, just like electrical power that would be presented at an electrical wall outlet. Inverters are utilised for a lot of… Read More »



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