Abstract: A constant-current controller that supplies a constant current to an inductive load. This controller comprises an electric control circuit module. The electric control circuit module comprises a primary switch and a secondary switch. During a time interval in which the primary switch is closed (ton), the secondary switch is open and the voltage across the inductive load is equal to the source voltage (Vs). At time ton until the end of a time interval (T), zero volts appears across the inductive load. During this interval, current continues to flow as supplied by the energy stored in the inductance. The periodic current in the inductive load becomes constant with a sufficiently large PWM switching frequency and is dependent upon the parameters of the control circuit and the duration of ton.

Abstract: A novel and useful degauss circuit for use with electromagnetic door locks. The door lock circuit is configured to provide a constant current to the electromagnetic coil load. A pulse width modulation (PWM) controller varies the frequency and/or duty cycle to a switch in series with the coil. Coil current feedback is used to adjust the PWM frequency and/or duty cycle so as to maintain the current through the coil at a certain level to maintain a desired holding force on the door lock. A degauss circuit inline with the current flowing through the coil is provided. When triggered either in an uncontrolled or controlled manner, a series RLC circuit that includes the coil inductance and resistance causes ringing to occur whereby the coil current reverses direction with sufficient amplitude and duration to degauss the coil.

Abstract: An energizable electromagnet of a door locking system is affixed to the door or the door frame for electromagnetically attracting an armature affixed to the other. A power control circuit is configured to selectively energize the electromagnet using a pulse-width modulated current cycle wherein two levels of magnetic force may be selectively applied to the system. A door position sensor is configured to provide a first communication signal to the power control circuit when the door is in a closed position. A second communication signal is provided when the door is not in the closed position. The electromagnet is energized at the lower level of magnetic force when the power control circuit receives the first communication signal and at the higher level of magnetic force only when an unauthorized attempt to open the door is initiated.

Abstract: A power control circuit assembly for an electric door latch mechanism comprises a load control circuit module configured to distribute a DC operating voltage to power an electromechanical door latch mechanism and its associated access control device. An energy storage device such as a rechargeable battery is coupled to the load control circuit module and is configured to deliver a DC voltage to the load control circuit module wherein the DC energy storage device voltage supplies the DC operating voltage. A rectifier is configured to receive an input AC voltage and convert the input AC voltage to an input DC voltage. The input DC voltage is adapted to deliver an energy storage device recharge voltage. An energy storage device voltage detection module is configured to interrogate a DC voltage supplied by the energy storage device.

Abstract: A power control system for use with an electric lock mechanism having an actuator comprises a power supply to output an output voltage to the actuator. A credential device signals the power supply to output the voltage upon receiving an authorized code. A microcontroller controls the power supply, the credential device, and the actuator and may operate in an Access Mode or a Dog Mode. When in Access Mode, the actuator is unpowered and the credential device is powered until an authorized code is received and the power supply powers the actuator. The Dog Mode has an awake mode where the actuator is powered and the credential device is unpowered after the actuator remains in the powered state for a length of time. A sleep mode has the actuator unpowered and the credential device powered until an authorized code is received and the power supply powers the actuator.

Abstract: A constant-current controller that supplies a constant current to an inductive load. This controller comprises an electric control circuit module. The electric control circuit module comprises a primary switch and a secondary switch. During a time interval in which the primary switch is closed (ton), the secondary switch is open and the voltage across the inductive load is equal to the source voltage (Vs). At time ton until the end of a time interval (T), zero volts appears across the inductive load. During this interval, current continues to flow as supplied by the energy stored in the inductance. The periodic current in the inductive load becomes constant with a sufficiently large PWM switching frequency and is dependent upon the parameters of the control circuit and the duration of ton.

Abstract: A power control circuit assembly for an electric door lock comprises a load control circuit module configured to distribute a DC operating voltage to power an electromechanical door latch mechanism and its associated access control device. An energy storage device such as a rechargeable battery is coupled to the load control circuit module and is configured to deliver a DC voltage to the load control circuit module wherein the DC energy storage device voltage supplies the DC operating voltage. A rectifier is configured to receive an input AC voltage and convert the input AC voltage to an input DC voltage. The input DC voltage is adapted to deliver an energy storage device recharge voltage. An energy storage device voltage detection module is configured to interrogate a DC voltage supplied by the energy storage device.