Sensor and control circuit diagrams
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.
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A simple device to indicate various levels of hot water in a tank.
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Beeper or flashing LED alert 1.5V battery powered portable unit
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Simple photo-sensitive circuit. 3V battery supply
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Beeps if you leave open the door over 20 seconds
3V battery operation, simple circuitry
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This circuit uses a single op-amp and the output is triggered by two different voltage levels.
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This is a simple Laser communication system. It can transmit and receive signal from any audio device.
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Controlled by indoor and outdoor temperature
Simple, high reliability design
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The counter is advanced by one touching a wire of the LED, Suitable for many applications
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This is a single channel (on / off) universal switch that may be used with any Infra Red remote control using 36-38kHz. (This is a very common remote handset frequency). In place of IR1 a TSOP1738 receiver may be used.
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