We found this circuit in an old American documentation. The operational amplifier is from the time and the output used to control an SCR or other power control.
This circuit was obtained in an English publication from 1981. The 7555 is the CMOS version of the...
This intercom for the 27 MHz band was found in a recent English documentation, working with a...
We found this circuit in an old Popular Electronics. The circuit can be applied to other...