Found in a 1970 EEE, this circuit can be applied to TTL ports. The supply is 5 V and the frequency, which depends on the crystal, can be between 1 and 3 MHz.
A version of a monostable that uses the 4528, but is triggered by negative transitions of the...
We find this filter with three operational of the time in an American documentation of the 80s....
This sensitive AM radio doesn’t need external antenna, picking easily local stations. The output...