This circuit is the power supply for the amplifier in the previous circuit. The transformer is 5 A with a voltage of 45 V, obtaining 70 V after rectification.
The automatic modulated siren circuit shown in the figure really produces an interesting sound...
This circuit was found in the August 1973 issue of Radio Electronics magazine. The Darlington...
This circuit has three settings, central sound frequency, modulation speed and modulation depth. The...