Abstract: A control apparatus controlling the operation of pulse width modulator for an electric clutch or electric motor in portable spray painting equipment having a pressure transducer for sensing the pressure, a manually adjustable pressure reference, a comparator type error detector, and a pressure deadband control for inserting a deadband in a pressure control loop with the deadband varying as the pressure reference varies. A fixed deadband is provided below a predetermined low pressure setting to avoid excessive cycling of the control apparatus during low pressure operation. The pulse width modulator control circuit includes compensation for improving input power factor. The clutch control includes an active alternative load circuit switched in when the alternator output voltage is above a predetermined value.

Abstract: A surveillance system includes a track positioned along a selected path and a moveable carriage supported by the track. A pair of electrical conductors mounted adjacent and parallel to the track provide power to a drive assembly mounted on the carriage. Video cameras are mounted to the carriage for monitoring selected regions adjacent to the path. Output signals from the cameras are transmitted on the conductors to a remote monitoring location. In the preferred embodiment, control signals for controlling placement of the carriage along the track are also transmitted on the conductors.