Category Archives: Power Electronics


This is variable DC power supply circuit, or we can call it adjustable DC power supply which give us a 1.2V-25V output voltage. The power supply schematic above is taken from the datasheet of regulator LM338K manufactured National Semiconductor. The circuit uses IC LM338K as the voltage regulator, so we Read more…


Solidstate Automatic Power-Off on Mains Failing

The following schematic diagram is the circuit of solidstate automatic power-off on mains failing. A really good number of circuits which shut down the power to the load on mains failure have definitely currently shown up in EFY. This circuit is different compared to other similar circuits since it consumes Read more…


Desktop Power Supply Circuit Electronic

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 Read more…


Cell Phone Shield with Charger

This is the cell phone shield circuit which can be used as mobile charger. Give protection to your cell phone from unexpected use or theft working with this easy circuit. It is able to produce a loud chirping sound when someone tries to take away the mobile handset. The added Read more…


Simple Mobile Phone Battery charger circuit diagram

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 Read more…


Simple Battery Level Indicator

Here the circuit diagram of simple and easy made battery level indicator. In general, in mobile phones, the battery levels is displayed in dot or bar style. This helps you to effortlessly acknowledge the battery level. On this page we provide a circuit that helps you to recognize the battery Read more…


Power Supply Failure Alarm Circuit Electronic

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 Read more…


Recommend

Recent Circuits