DYNA Speed Switches

The Barber Colman two setpoint speed switches normally obtain thier input signal from a magnetic pickup which is positioned in proximity to the teeth of a gear on a rotating shaft. The pickup generates an AC signal voltage whose frequency is directly proportional to the rate at which the gear teeth pass by the pole piece. The speed switch converts the input signal voltage in a DC signal which is compared to the preset levels (setpoints) and actuates the relays when the input signal frequency exceeds the preset values.