This circuit causes a buzzer to emit an intermittent tone when the temperature sensed by the diode, used as a sensor, exceeds a certain value set in P1. R2 and R3 determine the tone emitted and the transducer BZ is a common piezoelectric capsule. The circuit can be supplied with voltages from 3 to 15 V. The circuit is from the book Fun Projects for The Experimenter by Newton C. Braga, published in the United States.
| Clique na imagem para ampliar |
