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.


12 Volt Zener Regulated Charger

12V Voltage Regulated Charger

D Mohankumar - 12/09/2010

Most of the battery chargers do not have current and voltage regulation provisions. The step down voltage is [...]
12 volts symmetric power supply circuit schematic

12 Volt Symmetric Power Supply Circuit

D Mohankumar - 12/05/2010

Here is the standard symmetric power supply using the Positive and Negative Voltage regulator ICs. It can give [...]
infrared invisible alarm circuit

Invisible Infrared Alarm Circuit

D Mohankumar - 12/01/2010

This circuit uses invisible infrared light to detect the movement of people through the door. A short beep [...]

LM311 Datasheet

D Mohankumar - 11/28/2010

LM311 is an excellent Operational amplifier capable of driving DTL, RTL, TTL, or MOS logic. The output can [...]
touch controlled mute switch circuit

Touch Controlled Mute Switch with 555 IC

D Mohankumar -

Here is another simple circuit to mute the volume of Audio devices through simple touch. It exploits the [...]
flashing ornamental leds circuit

Ornamental Flashing LEDs

D Mohankumar -

This circuit can flash three sets of LEDs with different levels of Flashing. It can be used as [...]

LED Scanner Circuit

D Mohankumar - 11/20/2010

Here is a simple LED chaser simulating a scanner through the back and forth light effect. It used [...]
555 timer positive trigger circuit

Positive Trigger Timer Circuit

D Mohankumar - 11/19/2010

This 555 timer is designed unusually to give a positive output through a control over its reset pin. [...]
remote control light switch circuit

Remote Controlled Lighting Circuit

D Mohankumar - 11/06/2010

This remote controlled switch circuit can control AC loads such as lights, fans etc through the remote handset [...]

Telephone Tapping Indicator

D Mohankumar - 11/05/2010

This simple circuit can indicate a misuse or tapping of Telephone line through a loud alarm. The circuit [...]