Found in an Electronic Design from the 80's, this circuit monitors a three-phase line, activating a relay when one of the phases is missing.
This RF preamplifier for the 450 MHz band was found in an amateur radio documentation from the...
With this circuit, found in a 1978 publication, we can measure capacitances from 5 pF to 1 uF. The...
This circuit triggers an LM380 oscillator, producing an audio tone with light falling on the LDR....