This receiver uses old transistors that are equivalent to BC548 and BC558. The photo diode is of any type. The receiver can be used on a highly sensitive audio link.
This circuit can generate signals in the range from 1 to 20 kHz, depending on the crystal. The...
The basis of this circuit is an LM380 that drives a speaker that emits sound when moisture is...
Using the ICM7555, CMOS version of the 555, this circuit produces a 1 kHz signal. The circuit has...