This simple 12 V power supply with current up to 2 A was found in a Popular Electronics from the 90s. The zener diode is 14 V and transistor Q2 can be a TIP42.
We found this circuit in a 1987 documentation, but it can still be easily assembled. Its output must...
This circuit that emits siren sound can be used in a fire alarm. We found it in an old American...
Found elsewhere in this section, this circuit is from the April 1971 Radio Electronics magazine. Note...