Infrared Remote Control Timer
Presented here is a infrared remote controlled timer circuit. The circuit comprises two sections, namely, the transmitter section and the receiver section. Fig. 1...
Simple Video Amplifier
There are times when you want to view the video clips taken by your camera on your TV. You can do so by interfacing...
Electric Shock Gun
This is a fantastic circuit for self-protection. In case a burglar intrudes your house, you can use this electric shock gun as a weapon...
Sound Scanner
This novel sound scanner sweeps all sound vibrations in its vicinity and converts them into audible beeps. It can sense sound vibrations up to...
Simple Smoke Detector
This simple smoke detector is highly sensitive but inexpensive. It uses a Darlington-pair amplifier employing two npn transistors and an infrared photo-interrupter module as...
Economical Pump Controller
This automatic pump controller eliminates the need for any manual switching of pumps installed for the purpose of pumping water from a reservoir to...
0-100°C Temperature Detector
Here’s a temperature detector system capable of remote temperature reading without transmission losses in the conditioning circuit. The IC AD590 (IC4) is used as...
Intruder Detector Using Laser Torch
Here is a simple, low-cost intruder detector using laser torch to detect the intruder. The laser beam is produced using a 3V DC or...
Low-Cost Hearing Aid Using IC 741
This low cost hearing aid circuit offers the advantages of high sensitivity, low current consumption and light weight.
Audio signals are sensed by the condenser...
Digital Thermometer
This digital thermometer can measure temperatures up to 150C with an accuracy of +_1C. The temperature is read on a 1V full scale-deflection (FSD)...
Solidstate Signal Lamp
This solidstate signal lamp is a good alternative to revolving mechanical signaling lamps used in ambulances. It uses ultra-bright blue LEDs for signaling. However,...
Parallel Telephone with Secrecy and Call Prevention
This parallel telephone circuit provides secrecy when two or more telephones are connected in parallel to a telephone line. The circuit also prevents incoming...
IR Remote Switch
Imagine the convenience of selecting TV channels using your remote and then pointing the same remote to your switchboard to switch on/off the fan...
PWM Based Speed Control for DC Motors
There are several methods for controlling the speed of DC motors. One simple method is to add series resistance using a rheostat. As considerable...
Number Guessing Game
This number guessing game is quite simple. In this game the player thinks of any number between 1 and 99. Then he scans the...
8 Digit Code Lock for Appliance Switching
This 8 digit code lock is useful for appliances requiring exclusive or authorised use by those who know the preset code. If desired, the...
Cellphone Controlled Audio/Video Mute Switch
The circuit automatically disconnects power supply to the audio/video system whenever the mobile handset is lifted off the holder for making or receiving a call.
Dome Lamp Dimmer
A reading light inside the car greatly assists passengers during night, but often the interior dome lamp is too bright and distracting to the...