This is the power supply for the amplifier in the previous circuit. The voltage regulators must be equipped with a heat sink and the transformer is high current.
Analog Devives EVAL AD5941 Electrochemical Evaluation Board This board provided by Mouser...
Found in a Popular Electronics from the 90s, this Wien bridge oscillator uses a single-source...
Found in documentation from the 1980s, this circuit uses an operational amplifier from that time....