Indicated for powering circuits with operational amplifiers, this source was found in Popular Electronics. The output voltage depends on the transformer used, as well as the current.
This commercial receiver from the year 1958 uses two AA cells as Power supply. The circuit is...
PIC18F “K40” Features Intelligent ADC with Filtering and Signal Analysis Capabilities Ideal for...
This circuit appears in similar versions on this site. This is from a Popular Electronics from the 80's. The...