Abstract: An electronic lock utilizes two microprocessors remote from each other for enhanced security. The first microprocessor is disposed close to an input device such as a keypad, and the second microprocessor is disposed close to the lock mechanism and well protected from external access. The first microprocessor transmits a communication code to the second microprocessor when it receives via the input device an access code that matches a preset access code. The second microprocessor opens the lock if the transmitted communication code matches a preset communication code. The dual-microprocessor arrangement is advantageously used in a voice controlled access control system and in a motorcycle ignition control system. The present invention further provides an electronic access control system which has a master electronic key having a preset number of access, and an electronic alarm system for a bicycle that has a remote control mounted in the helmet of the rider.

Abstract: A vending machine uses a field-programmable electronic lock that learns a key code from a corresponding electronic key. The electronic lock has a learning process activation device that is accessible only when the door of the vending machine is in the open position. Using the learning process activation device, a service person activates the electronic lock to perform a key code learning operation, in which the electronic lock receives a key code transmitted from an electronic key and stores the key code in a non-volatile memory for future access control of the vending machine. Data encryption is employed in the communications between the key and the lock to ensure the security of the communications. Customized access limitations and a list of lock IDs are programmed into the electronic key to restrict when and how it can be used to access the vending machines. Access history data of the vending machines are collected for audit purposes by uploading the data from the vending machines to an electronic key.

Abstract: An accurate method of determining the power developed by selected cylinders of a multiple cylinder engine is based on the concept of controlling engine rpm for test purposes by adjusting the load on the engine instead of controlling speed by adjusting the fuel rate as is commonly done in normal engine operation. The method may be utilized for evaluating cylinder performance and for accurately balancing the output of the individual cylinders. It is particularly useful in railroad applications where the engine operates a generator that produces electric power and the system is provided with dynamic braking grids, which can be utilized as resistor grids for load testing the engine. However, the method is also applicable to other engines and other engine arrangements where engine power may be absorbed by a generator or dynamometer for controlling the load for test purposes.

Abstract: An electronic lock utilizes two microprocessors remote from each other for enhanced security. The first microprocessor is disposed close to an input device such as a keypad, and the second microprocessor is disposed close to the lock mechanism and well protected from external access. The first microprocessor transmits a communication code to the second microprocessor when it receives via the input device an access code that matches a preset access code. The second microprocessor opens the lock if the transmitted communication code matches a preset communication code. The dual-microprocessor arrangement is advantageously used in a voice controlled access control system and in a motorcycle ignition control system. The present invention further provides an electronic access control system which has a master electronic key having a preset number of access, and an electronic alarm system for a bicycle that has a remote control mounted in the helmet of the rider.

Abstract: An electronic lock utilizes two microprocessors remote from each other for enhanced security. The first microprocessor is disposed close to an input device such as a keypad, and the second microprocessor is disposed close to the lock mechanism and well protected from external access. The first microprocessor transmits a communication code to the second microprocessor when it receives via the input device an access code that matches a preset access code. The second microprocessor opens the lock if the transmitted communication code matches a preset communication code. The dual-microprocessor arrangement is advantageously used in a voice controlled access control system and in a motorcycle ignition control system. The present invention further provides an electronic access control system which has a master electronic key having a preset number of access, and an electronic alarm system for a bicycle that has a remote control mounted in the helmet of the rider.

Abstract: An electronic locking system with an access-control solenoid for controlling the operation of a locking mechanism is substantially immune to "hot-wiring." The locking system includes an actuating circuit for energizing the access-control solenoid. The actuating circuit is responsive to a modulated drive signal of a selected frequency to apply current through the solenoid to retract its plunger, while blocking externally applied DC voltages from reaching the solenoid. When an access code is entered through an input device, a control circuit of the locking system verifies the access code. When the code is verified, the control circuit generates the modulated drive signal to energize the solenoid to retract the plunger, thereby allowing the locking mechanism to be unlocked. After the plunger is retracted, the frequency of the modulated drive signal is changed to reduce the power consumption for retaining the plunger in its retracted position.

Abstract: An electronic access control system for controlling a lock in which the inputs and outputs are multiplexed, the electrically programmable read only memory is written to and read from in a serial manner, and the operator can disable access codes and enable access codes in one operation. The device reduces power consumption when powering a solenoid or DC motor by pulsing the output power. Further, the device is able to be operated in a remote location whereby the remote device can accept inputs from a keypad, an electronic signal, or a telephone line. The remote device, when not in active operation, operates in a low power mode so that the remote device may be powered by a battery.