This small switched regulator was found in an 60’s Optical Electronics. The circuit uses an integrated from the time, which is difficult to obtain today.
This battery status indicator was found in American documentation from the 1980s. The integrated circuit...
This input circuit for an oscilloscope was found in Radio Electronics from the 90s. The operating...
The resistors in this circuit marked with * must be within 1% tolerance. The circuit is from the...