This circuit was found in an American publication from 1965. The circuit uses components from that time. No information was given about the excitation transformer. Observe the high input power.
This sophisticated circuit is from old Motorola documentation, using common integrated devices...
This ultra-simple 9 V power source was obtained in an Argentine publication of the 1970s, but it...
Microsemi Le87536 Dual Differential Amplifier Microsemi / Microchip is making available through Mouser...