194 articles written by D Mohankumar

Author: D Mohankumar

About: I was a writter on but now I have my own site where I publish from time to time.


Electronic Components – An easy to use guide

D Mohankumar - 02/11/2013

Circuit designing and assembling is an interesting hobby. A large number of electronic components are now available in [...]
battery level monitor

Battery Level Monitor Circuit

D Mohankumar - 04/16/2011

This simple battery level monitor circuit can indicate the charging process in 12 Volt Lead Acid battery or [...]
transistor relay driver circuit schematic

Transistor Relay Driver Circuit

D Mohankumar - 01/31/2011

One of the serious problems in relay operated circuits is the relay clicking or chattering during the on/off [...]
door keys finder circuit

Keyhole or Door Keys Flashing Finder

D Mohankumar - 01/26/2011

This 3 volt Lithium cell operated LED flasher can be used as a keyhole finder in darkness or [...]
battery backup circuit schematic

Battery Backup Circuit

D Mohankumar -

This battery backup circuit can be added to surveillance systems like alarms and others to power the circuit [...]
220V led blinker circuit schematic

220V LED Blinker Circuit

D Mohankumar - 01/14/2011

Here is a simple LED blinker or flasher for decoration purpose. The 20 High bright LEDs flashes alternately [...]

Solar Panel Power System

D Mohankumar - 01/12/2011

The PhotoVoltaic (PV) power system uses solar panels to harvest energy from the sunlight. The PV panel is [...]
power resumption alarm circuit schematic

Power Resumption Alarm circuit

D Mohankumar - 12/26/2010

Here is a simple power resumption alarm circuit that can be fixed inside the switch box itself. It [...]
Christmas LED decoration circuit

Christmas LED Lights Circuit

D Mohankumar - 12/19/2010

Using this simple Christmas LED lights decoration circuit, you can make an 18 LED flasher to decorate the [...]
high temperature alarm schematic

High Temperature Alarm Circuit

D Mohankumar - 12/11/2010

The high temperature alarm will beep and LED blinks when the temperature of the device increases abnormally. This [...]