Hobby diy
Digital bike tachometer
This digital tachometer for bikes uses two reed switches to get the speed information of the bicycle. The reed switches are installed near the rim of the wheel where permanent magnets pass by. The permanent magnets are attached to the wheelspokes and activate the reed switches everytime they pass by it. The speed is digitally [...]
Autodisconnection for audio equipment
This simple circuit disconnects equipment rack of your audio in case has not delivered a sound a specified period. Circuit is operated by pressing his S1, which produces loading of C1. Further, switch IC1b AO exit in the state “up” and the audio equipment is powered from the network through semiconductor relay [...]
Mobile phone sniffer - gsm telephone detector
With this mobile phone sniffer will track down mobile phones. Use this handy directional finder in situations and locations where the use of a mobile phone is forbidden. This neat unit will not only detect the presence of mobile phone activity (voice or text), it can home in on the culprit!
Apart from mobile phones this [...]
