Digital Soil Moisture Tester
Here is a simple and compact digital soil moisture tester to check whether the soil is dry or wet. It can also be used...
Versatile Probe
You can use this versatile probe for continuity testing and identification of transistor type and transformer windings. The N-side or P-side of a transistor...
Multitone Siren
This multitone siren is useful for burglar alarms, reverse horns, etc. It produces five different audio tones and is much more ear-catching than a...
Overheating Indicator for Water Pipe
This circuit monitors the temperature of the water pipe. If the temperature of the pipe goes above certain limit, it flashes an LED.
Sixth Order Butterworth Low Pass Filter
Low-pass filters are widely used in the audio domain. Their most important application is in communication receivers and communication audio circuitry. These filters, when...
Smart Laptop Docking Station
You can easily convert your ordinary docking station into a smart electronic laptop docking station with an anti-theft alarm. The circuit presented here can...
Multi-utility flashlight
This multi-utility flashlight consists of three sections: a flasher, a sound-to-light display and a white LED-based flashlight.
Multi-utility flashlight circuit
The flasher circuit is built around...
White LED Light Probe for Inspection
This white LED light probe circuit is useful for inspecting narrow spaces like the inside of the CPUs, monitors, PCB modules and other electronic...
Digital Night Vision Goggle
At night, on highways, the high-intensity light from the headlight of heavy vehicles blinds oncoming light vehicle drivers (bike riders and car drivers) for...
Wireless Extender For IR Remote Controls
Using this system, you can control your IR-remote-controlled home appliances like DVD player and air-conditioner from another room without the hassle of running extra cables between the two rooms.
