Specifications

7
RY1 : VR15M121C (1 contact)
11. Relay
IC1 : UA741M
IC2 : CD4093
IC3 : CD4098
IC4 : NE555

12. IC's. Watch the position of the notch!
Construction
RY...
Apply some extra solder to the
wider PCB tracks, starting from
the relay contacts towards
contacts “NO” and “COM”.