This circuit generates rectangular signals from 2 Hz to 20 kHz using an operational amplifier. The circuit is from 1984 Radio Electronics. The power supply must be symmetrical.
This circuit uses two Raytheon RC4558 operational amplifiers that are similar to the 741. The...
This small stereo amplifier for headphones was found in a documentation on integrated circuits from...
This is a MOSFET version of a grid dip meter for frequencies between 1.8 MHz and 150 MHz,...