Found in a Popular Electronics from the 90s, this circuit activates a recorder for automatic recording of telephone calls. The circuit was used with old cassette recorders of the time.
The transmitter we have described, operates at a frequency between 88 and 98 MHz, with a range of the...
This is the circuit equivalent to the small key chains that were common in the 90s that emitted a...
This sophisticated digital timer was found in a 2002 documentation. Since CMOS integrated circuits are...