This old fashioned transistor amplifier was found in a publication of the year 1958. Transformer are the critical components in the circuit and power comes from 6 D cells.
This circuit produces a loud sound in the speaker when water level reaches the sensor. The power...
This circuit should be used with low frequency signals only. The circuit is from a documentation from the...
This Signetics circuit uses a double 555 (556) to generate tone bursts at frequencies determined by...