We have many tube tester circuits in this section. This one came out on a Radio Electronics from 1949 and has a very elaborate configuration with toggle switches.
Using the 709 integrated circuit, one of the first operational, this circuit was found in the...
This circuit can be used on a 0 to 14 V source with a current of 1 A. The PNP power transistor can be the...
The circuit presented is quite interesting due to the low-pass filter using the integrated circuit...