We found this circuit in a 1988 publication. A touch of the sensor causes the relay to trip and trigger a good-sounding intermittent siren. The circuit can be powered by batteries (6 V), but also by sources from 6 to 12 V if necessary. Q4 can be exchanged for a TIP32 heatsink for greater audio power. The relay must be according to the supply voltage.
| Clique na imagem para ampliar |
