Found in a 90's EDN this circuit can be used as a shield. The transistor is a general-purpose type and the frequency of the emitted sound is determined by R1 / C1.
September 2017 - Amphenol PcD's Solaris Connector series is available from Mouser Electronics. In...
This circuit was obtained in a 1967 General Electric documentation. It alternately fires two xenon...
This circuit is from a 1976 Motorola power semiconductor manual. In it we have the optical...