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October 27, 2010
This circuit operates a LED in pulsing mode, i.e. the LED goes from off state, lights up gradually, then dims gradually, etc. [more]
October 27, 2010
A common problem with small torches is the short life-span both of the batteries and the bulb. The average incandescent torch, for instance, consumes around 2 Watts. The LED Torch in Fig. 1 consumes just... [more]
October 27, 2010
Repell those repugnent insects from your Garden this Summer with this insect repellant circuit. Designed by Graham Maynard the circuitry consists of a phase locked loop (CMOS 4047) wired as a 22KHz oscillator. [more]
October 27, 2010
This circuit uses an MC3392 low side protected switch and an MC1455 timing circuit to form an automotive instrumentation panel lamp dimmer control. The brightness of incandescent lamps can be varied by Pulse Width Modulating... [more]
October 25, 2010
This nifty little circuit lets you record your phone conversations automatically. The device connects to the phone line, your tape recorder's microphone input, and the recorder's remote control jack. It senses the voltage in the... [more]
October 25, 2010
This circuit adopt a rather old design technique as its purpose is to vary the speed of a fan related to temperature with a minimum parts counting and avoiding the use of special-purpose ICs, often... [more]
October 23, 2010
This basic oscillator will detect the Earth magnetic field. The ferrite rod and coil are taken from an old Medium Wave receiver and a small magnet is glued at one end. [more]
October 23, 2010
The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. [more]
October 23, 2010
This circuit, enclosed in a small box, is placed in the fridge near the lamp (if any) or the opening. [more]
October 23, 2010
This circuit is intended to control a heating system or central heating plan, keeping constant indoor temperature in spite of wide range changes in the outdoor one. [more]
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