Sensor and control circuit diagrams
Connecting it to the door handle, it constitutes an effective as economic alert for your room, office, lab, or even drawer.
Read more...
The circuit uses a solar cell as the input transducer, blocks the DC produced by the cell, but amplifies the light received by the cell. Sunlight, moonlight, torchlight all produce sound which is amplified by this circuit.
Read more...
This circuit is intended for audio surveillance of an unattended area, examples being a back garden or open space. It can be used to listen for wildlife or just as an extra pair of ears.
Read more...
One LED monitors three levels: 50, 70 & 85 dB
Useful to detect too noisy environments
Read more...
Compact, transformerless circuitry. No relays employed
Read more...
LED or bulb switch off with a puff. Funny gadget - 3V Battery supply.
Read more...
This is a battery powered IR Link which may be used in more than one room. The standby current is extremely low - giving a good battery life; and by shutting down in the presence of extraneous IR radiation it copes with the problem of excessive output current.
Read more...