Electronic access control device

A method of assembling an electronic access control device, the access control device having a keypad and a microprocessor-based control circuit including a microprocessor and a non-volatile memory for storing a manufacturer-inserted permanent access code for controlling operation of the access control device, the method comprising:

• installing the non-volatile memory in the microprocessor-based control circuit, the non-volatile memory not having said manufacturer-inserted access code stored therein;
• installing a communication port connected to the microprocessor-based control circuit for accessing the non-volatile memory, the communication port being distinctive from the keypad;
• completing assembling the microprocessor-based control circuit;
• and
• after the completion of the microprocessor-based control circuit, writing said manufacturer-inserted permanent access code to the non-volatile memory through the communication port;
• and
• reading said manufacturer-inserted permanent access code back from the non-volatile memory through the communication port for confirmation.

An electronic access control device comprising:

• a microprocessor-based control circuit;
• a battery pack providing electrical energy at a battery voltage;
• a voltage regulator receiving the battery voltage and generating a regulated voltage for powering the microprocessor-based control circuit;
• and
• a low-battery detection circuit including a voltage divider having an input end connected to the battery voltage and an output end providing an output voltage, a first transistor in series with the voltage divider for controlling current flow through the volt age divider, a second transistor having an input end connected to the regulated voltage and a base connected to the output voltage of the voltage divider, the voltage divider turning the second transistor on when the output voltage of the voltage divider falls below a predetermined voltage,
• the control circuit having a control line connected to a base of the first transistor for selectively turning the first transistor on and off, and a sensing line connected to an output end of the second transistor for sensing the on/off state of the second transistor.

An electronic lock comprising:

• a lock;
• a solenoid coupled to the lock for opening and closing the lock;
• a battery having a voltage for providing power to energize the solenoid;
• a microprocessor-based control circuit including a driver circuit for energizing the solenoid and a timer, the control circuit controlling the driver circuit to apply the voltage of the battery to the solenoid to supply sufficient power to energize the solenoid to move a plunger of the solenoid into an open position to allow opening of the lock and then to supply a lower non-zero amount of power to energize the solenoid to hold the plunger in the open position until a preset time has elapsed as specified by the timer.

A method of assembling an electronic access control device for mounting on a storage device, the access control device having a keypad and a microprocessor-based control circuit including a microprocessor and a non-volatile memory for storing a manufacturer-inserted permanent access code for controlling operation of the access control device, the method comprising:

• installing the non-volatile memory in the microprocessor-based control circuit, the non-volatile memory not having said manufacturer-inserted access code stored therein;
• installing a communication port connected to the microprocessor-based control circuit for accessing the non-volatile memory, the communication port being distinctive from the keypad;
• completing assembling the microprocessor-based control circuit;
• and
• after the completion of the microprocessor-based control circuit, writing said manufacturer-inserted permanent access code to the non-volatile memory through the communication port.