Eltra Corporation

Allied Corporation

Carl K Dudley

William J Roberts

Richard W Mattson

James A Purdy

A current sensing device includes an electrically conductive current shunt member (10), and a voltage-responsive member (12). The current shunt member includes a first portion (14) having a free end (20), and a second arcuate portion (16) including an arcuate slot (38) defined by a constant radius (45) centered about the free end (20) of the first section, so that when current is passed through the arcuate section (16), the voltage produced by the shunt (10) may be varied by pivoting the voltage-responsive member (12) retained at the free end (20) of the first member and at the arcuate slot (38), and bridging or spanning between this first free end (20) and the arcuate slot (38). Preferably, the current-sensing member (12) includes electrical or electronic circuitry, for providing an output when sensed voltage, proportional to current through the arcuate portion, exceeds a predetermined level.

Adjustable electrical shunt

An idle speed control system for controlling the idle speed of an internal combustion engine, to conserve fuel by allowing a lowered idle speed, whenever possible, as well as offering more than normal power when needed, is disclosed. This idle speed control system includes an actuator for moving a secondary idle stop member into operative position, having both a vacuum-operated section and a solenoid section for maintaining the actuator in operative position, regardless of the state of the vacuum-operated portion. The idle speed control system further includes a control circuit responsive to engine speed which applies an output signal to the vacuum-operated section of the actuator when engine speed falls below a predetermined minimum, maintains it for a predetermined period of time, momentarily removes it to determine if the engine is presently capable of idling above the predetermined minimum speed, and reapplies the output signal if engine speed then dips below the predetermined minimum speed. Once applied, the output signal is removed either by the timer function, or when engine speed increases above the predetermined maximum idle speed. The control circuit also provides a signal to the solenoid portion of the actuator, in response to predetermined major accessory loads which may be imposed upon the engine in a vehicle.

Idle speed controller

A wear-indicating brush and warning circuit adapted to convey an indication to an operator that a dynamoelectric machine provided with such a brush is in need of maintenance before the brush wears to the point that a rotor contact surface is damaged by contact with electrical connections to the brush are disclosed. A brush (10) having current carrying pigtail leads (16) embedded therein includes a wear-detecting wire (20) embedded in the brush a short distance (A) beyond the lowest extent of the pigtail leads (16). The wire (20) is insulated over its periphery, including its tip (24), the insulation (26) being abraded by contact with the rotor contact surface (50), so that the wire (20) senses the voltage present thereon. Non-latching warning circuits (66, 66a) are disclosed, with and without the use of an isolating resistor within the dynamoelectric machine to permit the use of a single wire between the machine and the warning circuit. Also disclosed is a warning circuit for indicating that an input is electrically connected to a voltage, for indicating that a line (20) has contacted a rotor contact surface. The voltage sensed may be negative or positive, over a wide range, so that the positioning and number of brushes (10) is irrelevant. The circuit (92) includes an oscillating voltage source (122) and comparison circuits (122, 124, 128) giving a warning indication when an input line is connected to a voltage and is unable to follow the oscillating voltage.

Voltage detector using an oscillator and comparator means

A wear-indicating brush and warning circuit is adapted to convey an indication that a dynamoelectric machine is in need of maintenance before the brush wears to the point that a rotor contact surface is damaged by contact with electrical connections to the brush. A brush (10) having current carrying pigtail leads (16) embedded therein includes a wear-detecting wire (20) embedded in the brush a short distance (A) beyond the lowest extent of the pigtail leads (16). The wire (20) is insulated over its periphery, including its tip (24), the insulation (26) being abraded by contact with the rotor contact surface (50), so that the wire (20) senses the voltage present thereon. Non-latching warning circuits (66, 66a), with and without the use of an isolating resistor within the dynamoelectric machine to permit the use of a single wire between the machine and the warning circuit to provide a brush wear indication. Also disclosed is a warning circuit for indicating that an input is electrically connected to a voltage, for indicating that a line (20) has contacted a rotor contact surface. The voltage sense may be negative or positive, over a wide range, so that the positioning and number of brushes (10) is irrelevant. The circuit (92) includes an oscillating voltage source (122) and comparison circuits (124, 126, 128) giving a warning indication when an input line is connected to a voltage and is unable to follow the oscillating voltage.

Growing community of inventors

Petersburg, MI, United States of America

Carl K Dudley