A solenoid control circuit can make measurements during operation to determine the state of a solenoid and can provide for rapid re-energization of a solenoid upon detection of a dropout condition. A method of controlling a solenoid can include closing an input switch, cycling a low side switch based on voltage drop across a resistor, opening the input switch after a time interval, closing the low side switch and driving a discharge switch to control the discharge current rate from an energy storage device to an inductor. The method can include determining a condition of the inductor based on a time interval between actuation of comparators and maintaining a level of energy in the energy storage device sufficient to cause the inductor to produce a magnetic field for actuating a valve.

Apparatus for generating high pulse voltage comprises a high DC voltage source, a low DC voltage source, an inductive load, two controllable gates, a controllable switch and, connected in series, a capacitor, a booster diode and an additional controllable switch, as well as a controllable pulse duration converter for pulses from a rectangular pulse generator. The preceding connection of the booster diode anode with the negative terminal of the low DC voltage source ensured by the pulse duration converter and second controllable switch correlates the booster diode switching time with the moment of closing the both controllable gates. Thus, the pulse noise present in the prior art designs is eliminated, and the level of interference emitted into the surroundings is decreased.

This motor control device has an inexpensive configuration and enhances motor current target value tracking. This motor control device has an H bridge circuit that has a switching element and is connected to a motor coil provided in a motor, and a control means that drives the switching element at each prescribed PWM period and specifies an operation mode for the H bridge circuit from among a charge mode for increasing the motor current (Icoil) flowing through the motor coil, a fast decay mode for decreasing the motor current, and a slow decay mode. In each PWM period, the control means selects one of the operation modes on the basis of the result of comparing the motor current and a current reference value (Iref) before the time that has passed from the start of the PWM period reaches a prescribed current control re-execution time (Tr) and selects one of the operation modes on the basis of the result of comparing the motor current and the current reference value after the time that has passed reaches the current control re-execution time.

A latch system includes a releasably secured latch or keeper and a solenoid assembly. The solenoid assembly has a solenoid driver coupled to a power supply, a switching circuit connected with the solenoid driver, and a function generator to selectively adjust a frequency of a pick current output from the power supply and provided to the solenoid driver. The frequency is adjusted until the pick current induces a resulting vibration of said latch system sufficient to free a preloaded latch or keeper. The adjusted frequency may be a target frequency or a range of frequencies. Also included may be a preload sensor. When a preload is sensed, the frequency may be adjusted by the function generator until the pick current induces a resulting vibration of said latch system sufficient to free a preloaded latch or keeper.

An apparatus can comprise a circuit and an electrical element coupled to the circuit. The circuit can include a pulse generator to generate an electrical pulse having a first power and a load. The electrical element can be configured to receive heat that is converted into electrical energy by the circuit to apply a second power, greater than the first power, to the load.

A load driving apparatus supplies an electric power to a load via a full-bridge circuit. The load driving apparatus detects a load current by a current sensing resistor. A controller in the load driving apparatus generates a drive signal by switching between a first reference circuit outputting a first reference signal with a first reference cycle and a second reference signal outputting a second reference signal with a second reference cycle. A calculator in the load driving apparatus is used to supply a drive signal to the full-bridge circuit for supplying power to the load. When the controller 13 detects that the value of the load current is not reaching predetermined current threshold values, within either of the first reference cycle or the second reference cycle due to temperature fluctuations, the controller switches to either the first reference circuit or the second reference circuit to stabilize the value of the load current around an average value.

A circuit for polarizing magnetic material using a magnetic field of an excitation coil includes a port configured to provide a connection with a DC power supply. The circuit also includes at least one capacitor and driver circuitry configured to drive the excitation coil and the at least one capacitor. The driver circuitry is configured to discharge the excitation coil to the DC power supply via the at least one capacitor.

A method includes switching a switching circuit of the switched-mode power supply in a synchronous mode by turning on and off switches of the switching circuit in synchrony with a clock signal, wherein the switching circuit is coupled to an inductive element, and wherein the synchronous mode comprises a charging phase and a discharging phase; switching the switching circuit in an asynchronous mode by turning on and off switches of the switching circuit without being synchronized with the clock signal, wherein the asynchronous mode comprises a charging phase and a discharging phase; charging the inductive element during the charging phase of the synchronous mode; discharging the inductive element during the discharging phase of the synchronous mode; charging the inductive element during the charging phase of the asynchronous mode; and discharging the inductive element during the discharging phase of the asynchronous mode.

Provided is an electric control unit which is configured to switch the functions of an LCC, an HSD, and an LSD depending on a load to be connected. A power-supply-side switching element 102 is provided in a path L1 between a power supply 401 and a connector terminal 301. A ground-side switching element 106 is provided in a path L2 between a ground 402 and a connector terminal 302. A freewheeling diode 105 is provided in a path L3 connected to a connection point P1 between the power-supply-side switching element 102 and the connector terminal 301 and a connection point P2 between the ground-side switching element 106 and the connector terminal 302. A switching element 104 is provided in the path L3.

An apparatus for driving an inductive load, includes a switching element provided in a current flowing path of the inductive load, a diode connected to the inductive load in parallel, a current detecting resistor detecting current flowing through the inductive load, a peak hold circuit holding voltage detected by the current detecting resistor when the switching element is on, when the switching element is off, and a control section controlling current flowing through the inductive load by turning on/off of the switching element at a duty ratio in response to a target current value while the control section performs feedback control of output of the peak hold circuit. The control section controls current that flows through the inductive load when the duty ratio is larger than a threshold value and controls voltage that applies to the inductive load when the duty ratio is smaller than the threshold value.