We found this circuit in a 1965 Electronic Design. Transistors are still common but admit equivalents for some of them. The circuit drains a current of only 4 mA.
The gain of this circuit is given by the value of R1 that depends on the current in the...
This hydromassage circuit was found in a 1967 General Electric publication. The SCR is according to the...
Published in 1988 in Hands-On Electronics, this circuit converts the 12 V of a battery into 120 V...