Using a standard multimeter, this circuit from a 73 magazine for radio amateurs provides an output proportional to the inductance under test. The circuit is TTL and must be powered with 5 V.
If we modulate a beam of light from an LED, for example, we can receive this beam of light at a...
This circuit is from a publication of the 70s, but it can be easily assembled with the BC548. The...
In the circuit in the figure, when a pulse of light falls on the LDR, the circuit arms with the...