Soldering Iron Temperature Controller
When soldering, sometimes the need arises to control the temperature of the soldering iron. It is not possible to change the solder iron every...
Harvesting Radio Frequency Energy
Most people do not realise that there is an abundance of energy all around us, at all times. We are being bombarded with energy...
Noise Meter
Normally, sound intensity up to 30 dB is pleasant. Above 80 dB, it becomes annoying. And if it goes beyond 100 dB, it may...
Automatic Heat Detector
This automatic heat detector circuit uses a complementary pair comprising NPN metallic transistor T1 (BC109) and PNP germanium transistor T2 (AC188) to detect heat...
Musical Alarm Timer
A timer is a specialised type of clock for measuring time intervals. Here we present a simple musical alarm timer that can be used...
Low-Cost Hearing Aid
Commercially available hearing aids are quite costly. Here is a low-cost hearing aid circuit that uses just four transistors and a few passive components.
On...
Keychain Light
A keychain light with white LED comes in handy to help you at your front door or search your valuables in the dark. The...
PC Based Candle Igniter
Here’s a PC based candle igniter system that lets you light up a candle using matchsticks by just pressing the ‘Enter’ key on the...
Flashing Headlight for Motor bikes
The dipper for a vehicle’s headlight changes the light from high beam to low beam or vice versa given a particular set of road...
Car Fault Indicator Alarm
Here’s a car fault indicator alarm circuit that sounds an alarm if your turn indicator lamps doesn’t glow, helping you to safeguard against any accident...
