Posts Tagged ‘touch alarm’



Simple Knock Alarm With Piezo Sensor

Tuesday, August 10th, 2010

This circuit uses a thin piezoelectric sensor to sense the vibrations generated by knocking on a surface; eg, a door or table. Basically, it amplifies and processes the signal from the sensor and sounds an alarm for a preset period. In operation, the piezoelectric sensor converts mechanical vibration into an electrical signal. This sensor can [...]

Create music with hand touch

Saturday, June 12th, 2010

Operation of the circuit. In the normal range will not work Piezo Tweeter speakers on tap, but not the point of A Q1 Q2 will flow and the work of the bias voltage fall across R2. And the current flowing into pin 2 of IC1 IC1 make music production work out of three legs with [...]

Protects steal touch model by IC741

Friday, October 17th, 2008

Contain divide this friends many you may face a problem economical. A steal the very. Today I then beg for to advise the circuit protects steal again model that interesting. It is model to touch , the system will work when , steal touch at the metal detects. When you see the circuit may like [...]