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 circuit shown is from the GE semiconductor manual of 1977. In the table we have the values of the...
This 1967 Ferranti circuit uses company components. These transistors can be replaced by modern...
This 15 V regulator uses the integrated 100 mA L series. The circuit was suggested by Motorola's Linear...