This alarm siren circuit has a latch. We found it in an article in the January 1975 Radio Electronics magazine. Note the power given by Rx and the speaker. It can be increased by changing Q1.
The difference in this circuit, found in documentation from the 90s, is the use of a single...
This circuit generates pulses whose duration determines the position of a remote-control servo. The...
We find this circuit in 1975 documentation. The circuit can be used with other operational...