We found this circuit in the Radio Electronics magazine of February 1993. The main integrated circuit is from that time and the power supply is made with voltages of 6 to 15 V.
This circuit automatically inverts the test leads connection according to the polarity of the...
This circuit was found in a publication from the 90s. The circuit can be assembled with modern...
This filter, from an audio publication from 1977, passes the frequency range corresponding to the...