AC Motor Control Circuits Worksheet - AC Electric Circuits Notes: This circuit is known as a latching circuit, because it “latches” in the “on” state after a momentary action. The contact in parallel with the “Run” switch is often referred to as a seal-in contact, because it “seals” the momentary condition of the Run switch closure after that switch is de-actuated. The follow-up question of how we may make the motor stop running is a DC Motor Starters and Their Circuit Diagram | Electrical FIGURE 3: Four-point manual DC motor starter circuit diagram. An automatic starter operates in a similar fashion, except that automatic relays short out sections of the starter resistance either by a time sequence or when the armature current drops to a selected value. Automatic DC starters. Figure 4 shows the automatic DC starter circuit diagram. Motor Starters :Types of starter, Working of starter and Motor Starters :Types of starter, Working of starter and it’s circuit diagram April 10, 2018 August 21, A soft starter is another form of reduced voltage starter of AC induction motors soft starter employes the solid state devices to control the current flow and therefore the voltage applied to the motor.