Current limiting solenoid driver
Patent 5347419 Issued on September 13, 1994. Estimated Expiration Date: 
December 22, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 22, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesPower supply circuitry Strobed DC-DC converter with current regulation 5120143 Excitation current device for automotive electromagnetic clutch Driver device for a duty solenoid valve Current control circuit for an electromagnetic type actuator Patent #: 5214561 InventorsApplicationNo. 994779 filed on 12/22/1992US Classes:361/154, Including means to establish plural distinct current levels (e.g., high, low)323/222, Using choke and switch across source323/225, Plural devices323/282, Switched (e.g., switching regulators)361/152, Including particular drive circuit361/187Voltage or current level discriminatorsExaminersPrimary: Pellinen, A. D.Assistant: Krishnan, Aditya Attorney, Agent or FirmForeign Patent References
International ClassesH03K 003/01H03K 005/08 F02D 041/20 G05F 001/40 AbstractA solenoid driver applies an actuation current to a solenoid for a predetermined period and a lower holding current thereafter. A switching device pulses the applied current within upper and lower limits to maintain the actuation and holding current amplitudes, the pulses being integrated by solenoid inductance into a substantially steady-state current. A multiprocessing unit determines the amplitudes of solenoid current. A signal representative of desired current amplitudes is compared with a signal representative of measured solenoid current, and a signal representative of the difference therebetween is used to control the switching device. Voltage developed across a resistor in series with the solenoid is input to a differential amplifier having connected to its output a peak detector that mimics the decay rate of current in the solenoid, the signal representative of measured solenoid current being obtained from the peak detector. Power dissipation by the solenoid driver is minimal, and the latter is capable of withstanding a continuous short to a source of electric current. The output of the peak detector is monitored by the microprocessing unit for the detection and logging of faults.Field of SearchVoltage or current level discriminatorsHolding means For relays or solenoids Including particular drive circuit Pulse initiated Including means to establish plural distinct current levels (e.g., high, low) With capacitor charging or discharging through coil With capacitor charging or discharging through coil Including instrument (e.g., meter-relay) Temperature indicating instrument Including means for using, or compensating for, the induced EMF of the electromagnetic device ELECTRIC CONTROL Having means to produce digital pulses Switched (e.g., switching regulators) Using choke and switch across source Plural devices | |
