Random circuits

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Cmos 4017 Sequential Timer

This timer will provide a sequence of up to ten separate events. The length of each event is set independently. And the sequence will run a fixed number of times - or repeat continuosly. The individual events within the sequence - can be made to repeat and/or overlap. The accompanying Support Material includes a detailed description of how the Cmos 4017 works.... [read more]

On Off Touch Switch Circuit

The modern mechanic switches are improved concerning of old technology. We need however many times to replacement some old switch or to check currents bigger than the durability of certain switches or simple we need something with modern appearance. For he and different reasons is essential the up circuit. It is simple in the manufacture and the materials that use they exist everywhere.... [read more]

An Expandable Multi-Zone Modular Burglar Alarm

This circuit features automatic Exit and Entry delays and a timed Bell Cut-off. It has provision for both normally-closed and normally-open contacts, and a 24-hour Personal Attack/Tamper zone. By using the Expansion Modules, you can add as many zones as you require; some or all of which may be the inertia (shock) sensor type.... [read more]

FET Audio Mixer

This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power.... [read more]

Adjustable Strobe Light

This one uses a much more powerful "horse shoe" Xenon tube which produces more light. You can also control the flash rate up to about 20Hz. Do not look directly at the flash tube when this thing is on!... [read more]

Intercommunication (Intercom)

This is a great intercom circuit that can be used in many ways. It uses 22V to operate and maybe it will work at a lower voltage (you can try it). For input/output it uses a loundspeaker (20-45 Ohm) on each side.... [read more]