The audio driving circuit for the logic probe. NE555 based. Intended to be used with a piezo-buzzer as the audio output device.

Control Signal Logic for the Logic Probe. Outputs control signals for LEDs and Audio circuits.

A simple Logic Probe. Light and sound made correspond to the logical values of 1, 0, or Undefined. Power is supplied externally by the circuit being probed or some external supply. Supports 5V TTL & 3.3V TTL/CMOS. No Microcontrollers used. Manufactured by JLCPCB.