Intercommunication (Intercom)


This is a great intercom circuit that can be used in many ways. It uses 22V to operate and maybe it will work at a lower voltage (you can try it). For input/output it uses a loundspeaker (20-45 Ohm) on each side.

Circuit diagram

Intercommunication (Intercom)-Circuit diagram

Componets Layout

Intercommunication (Intercom)-Componets Layout


Intercommunication (Intercom)-PCB


  • R1: 2,2 M
  • R2: 10 Ohm
  • R3,R6: 100K
  • R4: 22K
  • R5: 1M
  • C1: 0,2uF
  • C2: 0,02uF
  • C3: 0,001uF
  • C4: 0,05uF
  • C5: 100uF/40V
  • C6: 200uF/40V
  • IC1: PA234
  • LS1,2: 20-45 Ohm
  • T1: 2N3391 (BC383)
  • P1: 5K
  • S1: SW-DPDT *
Intercommunication (Intercom)

See here how the SW should be.