When the SCR (SCRll of the printed-circuit card) turns on, it allows current to flow through the SA (Step Armature) coil, which operates the stepping-switch armature.
The armature movement opens the SAl contact and closes the SA2 contact, as shown in Figure 6 and Figure 8. The opening of the SAl contact turns the SCR off and the closing of the SA2 contact completely discharges the capacitor, located on the