This simple low power triplicator was found in 90’s American documentation. The diodes can be general purpose types and the frequency is determined by the RC network of the 555.
This circuit produces a loud sound in the speaker when water level reaches the sensor. The power...
May 2016 - It can be obtained from Mouser Electronics new display 1092 from VDC. The new LED...
This Motorola circuit is from 1965. Collector currents must be 7 and 12 A for transistors....