Archive for April, 2008
Presence detector, proximity sensor circuit
This circuit react in presence of any conductor object including humans. This circuit does not detect object movement but can act as an proximity sensor!
Sensitivity is adjustable with P1 which will be located at a great distance from the rest of the presence detector circuit.
The presence detector is built with an Clapp oscillator at 1MHz.
Do [...]
CB - FM receiver, simple 27MHz fm receiver
This is a simple FM-CB receiver built with TCA440 for listening CB ( citizen’s band ) transmissions with FM ( frequency modulation ).
CB-FM receiver circuit schematic design:
1Hz generator and 2Hertz oscillator
This 1 Hz and 2Hz generator or oscillator is built with 4060 as an oscillator and a 14 bits counter. To obtain a 1Hz signal after 4060 we use 1/2 4013. This circuit provides a rectangular voltage with a amplitude between 0V and the power supply voltage.
To adjust this 1Hz generator connect to pin 9 [...]
