We found this circuit in a Radio Electronics from December 1963. The circuit combines valves and transistors and has a high input resistance. The circuit is powered by two batteries.
We found this circuit in an American documentation of the 80's, being indicated for the test of...
This amplifier for instrumentation with differential input is from the factory manual of the...
This circuit is from old technical documentation, used to monitor the voltage of a 12 V battery. The...