 Static Electricity - Negative Ion Detector
This device can detect negative ions in air. It has very few components: one FET, two resistors and battery. You also need multimeter to complete device. This device reacts, for example, on a TV radiation or air ionizer.
Coil Coupled Operation Metal Detector
One more kind of metal detectors.
Connection Tester
Simple connection tester built with famous 741 op-amp circuit. Very useful for every electronics workshop.
Sine Wave Generator
This oscillator produces sinusoidal wave. It's made around LF351 or TL071CN or TL081CN. A classic Wien Bridge oscillator
MILLIGAUSS METER
This device should measure electromagnetic energy, but only the one which human body absorbs.
Bench Amplifier
This circuit is basically an audio amplifier, but it is placed in this category because it may be used as signal tracer. It is built around simple National Semiconductor LM386 amplifier.
Signal Tracer and Injector
A simple test circuit to fault find audio and radio equipment. Can be used to inject a square wave signal, rich in harmonics, or used with headphones as an audio tracer
Beat Balance Metal Detector
A Beat Balance Metal Detector made from discrete components. Interesting design.
IR Remote Control Modulation Detector
A circuit to extract and measure the modulated carrier of an Infra Red remote control
Electromagnetic Field Detector
This circuit is sensitive to low frequency electromagnetic radiation and will detect for example hidden wiring or the field that encompasses a transformer.
Function Generator
Built around a single 8038 waveform generator IC, this circuit produces sine, square or triangle waves from 20Hz to 200kHz in four switched ranges.
Digital Radar Speedometer
It allows us to evaluate the speed of any object moving, especially cars and other vehicles
Metal Detector
A single chip metal detecor with a range of a few inches. This is useful for decting nails or screws in walls and floors, or for locating buried mains cable.
| 
