This old indicator circuit indicates only when the fuel reaches the sensor level. The integrated circuit is not common today. The circuit was found in documentation from the 1980s.
This amplifier circuit for the 7 MHz band, which corresponds to the 40-meter band of radio...
This high-power circuit from a Popular Electronics of the 80's makes use of common SCRs that admit...
This circuit is from an American documentation from 1975. The single junction transistors can be...