Ransburg Corporation

Frederick W Woodruff

Daniel C Hughey

William L Smart

A bi-directional system for ensuring that a ground connection is made in a three-wire conductor system including a line 'hot' conductor, a line neutral conductor, and a ground conductor includes a circuit for generating direct current potential related to the potential difference between the line 'hot' conductor and ground and a second circuit for generating a direct current potential related to the potential difference between the line 'hot' conductor and ground. A circuit including a male plug for insertion into a female receptacle includes a first prong for coupling alternatively to the line 'hot' conductor or the line neutral conductor, a second prong for coupling alternatively to the line 'hot' conductor or the line neutral conductor, and a third prong for coupling to the line ground conductor. Coupling of the first prong to the line 'hot' conductor causes the second prong to be coupled to the line neutral conductor and coupling of the first prong to the line neutral conductor causes the second prong to be coupled to the line 'hot' conductor. Conductors are provided for coupling the first circuit to the first and third prongs and for coupling the second circuit to the second and third prongs. Each of the first and second circuits includes a Zener diode for sensing the potential across the 'hot' and ground conductors and for switching in response to the presence of potential difference, which tends to indicate the presence of ground potential on the ground conductor.

Ground assurance circuit

An electrostatic charging potential generator for a coating dispenser is useful with, for example, hand-held dispensers where the dispenser can be brought into closely spaced orientation with articles to be coated, or 'targets.' The generator of the disclosure incorporates a 'fold-back' voltage-current characteristic including a reduced voltage-reduced current curve region in which the energy available at the dispenser is less than that necessary for spark ignition of solvents, atomized coating material particles, and the like suspended in the atmosphere around the dispenser.

Fold-back power supply

A system for controlling a high-voltage supply which is inhibited for a time after energization to prevent spurious deenergization. The high-voltage supply includes a source for generating a signal representative of the desired output high voltage. A feedback voltage control responds to this signal and controls the high-voltage supply. The system includes a source for developing a linear ramp signal which varies from an initial value at which the output of the high-voltage generator is under the control of the ramp signal source to a value at which the output of the high-voltage generator is under the control of the signal representative of the desired output high voltage.

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Indianapolis, IN, United States of America

Frederick W Woodruff