This hydromassage circuit was found in a 1967 General Electric publication. The SCR is according to the power of the heating element.
The presented circuit uses a symmetrical power source to supply an amplifier with the LM139 or...
This circuit was obtained from the 1995 Encyclopedia of Electronic Circuits Volume 5. The circuit...
The circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor. Some of...