Abstract: A solenoid for a vehicle starter includes at least one coil with a passage extending through the coil in an axial direction. The solenoid further includes a plunger configured to move in the axial direction within the passage. The plunger includes a cylindrical outer surface with a substantially uniform diameter and a circumferential notch. The cylindrical outer surface includes a first portion with a first diameter on one side of the circumferential notch, and a second portion with the first diameter on an opposite side of the circumferential notch. The circumferential notch includes a portion with a second diameter that is less than the first diameter.

Abstract: A solenoid for a vehicle starter includes at least one coil with a passage extending through the coil in an axial direction. The solenoid further includes a plunger configured to move in the axial direction within the passage. The plunger includes a cylindrical outer surface with a substantially uniform diameter and a circumferential notch. The cylindrical outer surface includes a first portion with a first diameter on one side of the circumferential notch, and a second portion with the first diameter on an opposite side of the circumferential notch. The circumferential notch includes a portion with a second diameter that is less than the first diameter.

Abstract: A solenoid for a vehicle starter includes at least one coil with a passage extending through the coil in an axial direction. The solenoid further includes a plunger configured to move in the axial direction within the passage. The plunger includes a cylindrical outer surface with a substantially uniform diameter and a circumferential notch. The cylindrical outer surface includes a first portion with a first diameter on one side of the circumferential notch, and a second portion with the first diameter on an opposite side of the circumferential notch. The circumferential notch includes a portion with a second diameter that is less than the first diameter.

Abstract: A solenoid for a vehicle starter includes at least one coil with a passage extending through the coil. A plunger is slideably positioned within the passage and configured to move in an axial direction between a first position and a second position. The plunger includes a substantially cylindrical outer surface portion with a circumferential notch formed in the outer surface portion. The at least one coil may include a pull-in coil and a hold-in coil wound on a spool. A plate member is positioned at one end of the spool and is separated from the plunger by a radial distance. The radial distance varies when the plunger moves in the axial direction as a result of the notch moving in relation to the plate member. A sleeve member may be coupled to the plunger such that the sleeve member covers the circumferential notch formed in the plunger.

Abstract: A solenoid for a vehicle starter includes at least one coil with a passage extending through the coil. A plunger is slideably positioned within the passage and configured to move in an axial direction between a first position and a second position. The plunger includes a substantially cylindrical outer surface portion with a circumferential notch formed in the outer surface portion. The at least one coil may include a pull-in coil and a hold-in coil wound on a spool. A plate member is positioned at one end of the spool and is separated from the plunger by a radial distance. The radial distance varies when the plunger moves in the axial direction as a result of the notch moving in relation to the plate member. A sleeve member may be coupled to the plunger such that the sleeve member covers the circumferential notch formed in the plunger.

Abstract: An electric starting system for controlling an electric starter that has a solenoid for shifting a pinion and for closing solenoid contacts to energize a cranking motor that drives the pinion. The solenoid has a single coil connected in series with a plurality of parallel connected field effect transistors. The circuit that energizes the solenoid coil through the field effect transistors is in parallel with the solenoid contacts and the cranking motor. The gates of the transistors are connected to an oscillator which causes the transistors to be repeatedly turned on and off at a predetermined frequency and duty cycle. Pulses of current are supplied to the solenoid coil which are sufficient to maintain the pinion meshed with the ring gear of an engine and to maintain said solenoid contacts closed without overheating the coil.

Abstract: An electronic starting motor control system for electric starting apparatus of a type that has a solenoid including a solenoid coil. Energization of the solenoid coil causes solenoid contacts to close and causes a pinion to be shifted into mesh with the ring gear of an engine to be cranked. The current supply to the solenoid coil is controlled by a plurality of parallel connected field effect transistors that are turned on and off. The system has a fail safe circuit which operates to cause the wire bonds of the field effect transistors to open in the event that a field effect transistor fails by shorting. The system has an overvoltage protection circuit which during an overvoltage condition shuts off the supply of voltage to the gates of the transistors and shuts off the voltage supply to a plurality of control circuits that are coupled to the gates of the transistors.