Voltec Incorporated

Lawrence J Mione

Peter Sabol

M Raymond Kallman

Electrical monitoring circuitry simultaneously and continuously tests a three-wire ground-type AC outlet for proper line voltage, polarity of the wiring and external ground resistance. The circuitry includes a single indicating lamp, preferably a light-emitting diode, which illuminates only when the proper conditions tested for exist at the outlet. For optimum convenience, the circuitry is incorporated in a male/female outlet adaptor which, in use, is plugged into the wall outlet to be tested, thereby to establish via the phase, neutral and ground prongs of the adaptor the necessary test connections of the circuitry to the wall outlet. The adaptor includes one or more jack receptacles internally connected to the adaptor ground prong for receiving static charges from external equipment and draining same to the building ground when the light-emitting diode illuminates.

Static grounding and monitoring accessory

A switching control circuit has first and second output terminals, the first output terminal being connected by way of a control resistor to one of a pair of input terminals which, in use of the circuit are connected to an electrical power source, the second output terminal being connected to the other input terminal. A sensing and delay portion of the circuit is connected across the resistor and, in response to current flowing through the resistor when the power switch of a first electrical device, such as a disc drive, connected to the input terminals is initially turned on, energizes a relay after a predetermined time delay elapses from the time that the resistor current reaches a given threshold value, the energized relay serving to connect one or more pairs of other output terminals of the circuit across the pair of input terminals, so that source power will then be supplied via the relay to the other output terminal pairs and to any other electrical devices, such as a monitor, printed and computer, whose power input terminals are respectively connected thereto. Following turn-off of the power switch, the same circuit portion deenergizes the relay after a second predetermined time delay elapses from the time that resistor current diminishes to a second given threshold value, so that source power to the other electrical devices will cease. Use of a high gain amplifier at the input of the sensing and delay portion of the circuit sharply reduces the power dissipation required of the resistor for any given threshold value of current therethrough, thus providing consequent cool operation and avoiding fuse or other line protection.

Growing community of inventors

Brentwood, NY, United States of America

Lawrence J Mione