This circuit is from Motorola's 1990 Linear Databook. We can implement it with other operational amplifier. The power supply must be symmetrical.
This circuit checks the oscillation capacity of a transistor. The circuit can be used with fixed...
The AC125 transistor is an ancient germanium type widely used in audio stages as a preamplifier. In the...
We found this circuit in a 1995 publication. It makes use of infrared LEDs of the type existing at...