This is the power supply circuit for the amplifier in the previous circuit. The source is adjustable and uses power transistors of the time. The AC transistor must be mounted on a heat sink.
This circuit is from an old documentation. However, it can be mounted with modern equivalent...
Using the 723 integrated circuit, this circuit was found in an article on power supplies in the...
A low voltage heating element (up to 30 V) with a current of up to 3 A can be precisely controlled with...