Low-cost Intercom Circuit Using Transistors
This is a circuit for a low cost intercom that is made by using transistors.
Sound Operated Lamp Switch
This inexpensive, fully transistorised sound operated lamp switch is very sensitive to sound signals and turns on a lamp when you clap within 1.5...
Infrared Toggle Switch
This infrared toggle switch can be controlled by any TV/VCR remote operating at 38kHz frequency. The circuit uses readily available, low-cost components and can be assembled on a small veroboard.
Smart Vibration Sensor
Machines nowadays require optimum parametes to operate at their best. Some operating conditions concerns include themperature extremes, magnetic intereference, vibration & electromagnetic intereference among...
Christmas Lights Using LEDs
This is a circuit that can be used as for festive decorations. It contains eighteen LEDs that can be assembled as one's wish.
Ultrasonic Burglar Alarm
This unique ultrasonic burglar alarm makes use of the invisible, inaudible ultrasonic sound beam to detect movements. Ultrasonic transducers operate at maximum efficiency when...
Touch Based Doorbell
This touch plate doorbell makes use of enhancement-mode MOSFETs forming part of CMOS quad NAND gate CD4007B in conjunction with a detector and Darlington driver stage.
Bicycle Indicator
The electronic bicycle turn indicator unit described here uses low-cost components and is a good substitute to many commercially available versions. It works in...
Locker Guard
Protect your valuables from burglary using this simple locker guard circuit. It generates warning beeps when someone attempts to open the locked safe. The...
Bell-Cum Light Controller
This is a circuit for a bell and light controller that consists of a doorbell with porch light. When someone presses one switch, the bell rings and the light turns on for 3 minutes. Another switch turns on only the bulb for 3 minutes.
PC Table Lamp
This useful circuit is built around well-known timer IC TLC555. It activates an electric bulb when your PC is switched ‘on’. When you shut down the PC, the lamp also automatically turns ‘off.’
Seismic Sensor
This circuit detects the movements of humans or animals. Whenever it detects any movement, a buzzer starts beeping and a red LED starts to blink.
Water Tank Overflow Indicator
Simple Overflow Stopper For Water Tanks
Stop Tank Overflow With Wireless Water Level Indicator and Controller
Water Level Indicator Circuit (LED...
Mains Supply Failure Backup Light
In the event of a sudden blackout at night, this mains supply failure backup light switches on automatically to provide sufficient light for around...
Portable Lamp Flasher
Here is a high power incandescent electric portable lamp flasher. It is basically a dual flasher (alternating blinker) that can handle two separate 230V...
Overspeed Indicator
This speed indicator circuit is designed for indicating over-speed and direction of rotation of the motor used in mini hand tools, water pump motors,...
220V Live Wire Scanner
Presented here is a 220V live wire scanner. The clock input of the IC is connected to a wire, which acts as the sensor....
Telephone Conversation Recorder
This is a circuit for a telephone conversation recorder that can record conversations over the telephone in a tape recorder...