Used to excite mag-netic specimens in frequency range of 0 to 110 kHz at outputs up to 12 A. Output stage uses two complementary pairs of emitter-followers connected so each pair forms half of bridge, using MJ4030 and MJ4033 Darlingtons mounted on Iiquid-cooled heatsinks. Article describes cooling arrangement and circuit opera-tion in detail and gives suitable preamp circuit for driving inputs of BCY89 dual transistor. De-signed for 32-VDC supply, which connects to top and bottom horizontal buses on diagram.
Feedback circuit are drawn in heavy lines. Re-sistors in series with Darlingtons (OR25, representing 0.25 ohm) are wound from resistance wire since they must carry large currents. Output impedance of circuit is less than 0.5 ohm, for matching to low-resistance load.-I. L. Ste-fani and II. Perryman, Liquid-Cooled Power Am-plifier, Wireless World, Dec. 1974, p 505-507.
Required Field 
