Without regulation, this basic circuit has the output current, and voltage determined by the transformer. The input can be 110 V and 220 V if the transformer used is of the indicated type.
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...