This circuit that emits siren sound can be used in a fire alarm. We found it in an old American documentation. The signal must be applied to a good audio amplifier.
This circuit controls a relay in a bistable way by touching the sensors type NF (CH3) and NO...
This circuit produces modulated tones in a loudspeaker. The effects can be adjusted by the...
This is a simulation of a Relaxation Oscillator using a programmable unijunction transistor (PUT). The...