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High Quality Intercom
High Quality Intercom
December 25, 2010

A very high quality intercom, which may also be used for room monitoring. [more]

Electronic Siren
Electronic Siren
December 19, 2010

An electronic siren made from discrete components. [more]

FM Transmitter Bug
FM Transmitter Bug
December 19, 2010

This small transmitter uses a hartley type oscillator. [more]

Automatic Headlight Brightness Switch
Automatic Headlight Brightness Switch
December 13, 2010

Driving the highway with your high-beam headlights can really increase your visibility, but can he a blinding hazard for other drivers. This simple circuit can be wired into your headlight switch to provide automatic switching... [more]

Bass-treble tone control circuit
Bass-treble tone control circuit
December 13, 2010

The LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. An additional control input allows loudness compensation to be simply effected. Four control... [more]

Emergency Light & Alarm
Emergency Light & Alarm
December 13, 2010

This circuit is permanently plugged into a mains socket and NI-CD batteries are trickle-charged. When a power outage occurs, the lamp automatically illuminates. Instead of illuminating a lamp, an alarm sounder can be chosen. [more]

Low impedance microphone amplifier
Low impedance microphone amplifier
December 13, 2010

The circuit is a microphone amplifier for use with low impedance (~200 ohm) microphones. It will work with stabilized voltages between 6-30VDC. If you don't build the impedance adapter part with T1, you get a... [more]

Motorola Hi-Fi power amplifier
Motorola Hi-Fi power amplifier
December 13, 2010

This is a very simple, low cost, Hi-Fi quality power amplifier. You can build it 5 ways, like it’s shown in the table (from 20 W to 80 W RMS). [more]

Bedside Lamp Timer
Bedside Lamp Timer
December 12, 2010

he purpose of this circuit is that of power a lamp or other apparatus for a given time (30 minutes in this case), and then to turn it off. [more]

Pulse Charger for reviving tired Lead Acid batteries
Pulse Charger for reviving tired Lead Acid batteries
December 12, 2010

If you own a motorcycle, a motor home, a caravan, a lawn mover, a day cruiser or maybe a vintage car you must at some point had to write off a lead acid battery. When... [more]



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