Switching circuit for rpm control of electrical machine

摘要

A double pole changeover safety switch (S;S1,S2) is connected in series with the motor (M), so that in a first switch position the machine is connected to the mains and in readiness for operation. In a second position simultaneously with separation from the mains, the switch introduces a short circuit-quick braking.A separate r.p.m. regulating-sequence switch (Ss) not coupled to the safety switch is operable independent of the latter, and so arranged that a switch off position is provided. The motor is thus slowed down, if the safety switch does not separately respond to the braking or is applied in response to opening of the appliance