Found in an American publication of 1968, this circuit makes use of a pilot light of the time. It can be replaced with LED with appropriate series resistor. Transistors may be modern equivalents.
In the figure we have the way to connect two high power operational amplifiers LM12 to double the...
This circuit uses the Linear Technology LT6505 and was found in a 2005 manual. The circuit is for 24 V...
a This circuit was obtained from a 1978 Practical Wireless. It causes a low-power 1.5V lamp to...