Abstract: An apparatus such as an electronic torque wrench (100) is provided that includes a strain gauge assembly (202), differential voltage amplifier circuit (204), analog-to-digital converter (ADC) (206) and processing circuitry (208). The strain gauge assembly (202) measures an applied torque, and produces an analog electrical signal that varies in voltage with the applied torque; and the differential voltage amplifier circuit (204) amplifies the analog electrical signal to produce an amplified analog electrical signal. The strain gauge assembly (202) has a characteristic analog signal produced without any applied torque, and the differential voltage amplifier circuit (204) is biased to a bias voltage that is calibrated to reduce the characteristic voltage in the amplified analog electrical signal. The ADC (206) converts the amplified analog electrical signal to an equivalent digital electrical signal.

Abstract: A tool storage system is provided that includes a drawer, and an optical system configured to detect presence of an object in the drawer. The optical system includes a photoelectric sensor and processing circuitry. The photoelectric sensor includes a light transmitter configured to emit pulsed light, and a photoelectric receiver configured to convert a reflection of the pulsed light off of the object to an electrical signal that indicates proximity of the object and thereby the presence of the object in the drawer. The processing circuitry is configured to output a pulse-frequency modulation (PFM) signal from which the light transmitter is driven to emit the pulsed light. The PFM signal has a frequency that is adjustable to control an average intensity of the pulsed light, the frequency calibrated for a type of the object and an effective range of the photoelectric sensor.

Abstract: A tool storage system is provided that includes a cabinet, a drawer assembly installed in the cabinet, a lock assembly, and processing circuitry. The drawer assembly includes a drawer operably coupled to the cabinet to enable the drawer to slidably open and close, and a sensor configured to detect a user action to open the drawer. The lock assembly is operably coupled to and between the cabinet and the drawer, and includes an electric lock configured to engage a latch when the drawer is closed, and disengage the latch to enable the drawer to open. The process-ing circuitry operably coupled to the sensor and the electric lock. The processing circuitry is configured to receive a signal from the sensor responsive to detection of the user action to open the drawer, and control the electric lock to disengage the latch responsive to the signal.

Abstract: A tool storage system is provided that includes a drawer, and an optical system configured to detect presence of an object in the drawer. The optical system includes a photoelectric sensor and processing circuitry. The photoelectric sensor includes a light transmitter configured to emit pulsed light, and a photoelectric receiver configured to convert a reflection of the pulsed light off of the object to an electrical signal that indicates proximity of the object and thereby the presence of the object in the drawer. The processing circuitry is configured to output a pulse-width modulation (PWM) signal from which the light transmitter is driven to emit the pulsed light. The PWM signal has a duty cycle that is adjustable to control an average intensity of the pulsed light, the duty cycle calibrated for a type of the object and an effective range of the photoelectric sensor.

Abstract: A tool storage system is provided that includes a drawer, and an optical system configured to detect presence of an object in the drawer. The optical system includes a photoelectric sensor and processing circuitry. The photo-electric sensor includes a light transmitter configured to emit pulsed light. and a photoelectric receiver configured to convert a reflection of the pulsed light off of the object to an electrical signal that indicates proximity of the object and thereby the presence of the object in the drawer. The processing circuitry is configured to output a pulse-frequency modulation (PFM) signal from which the light transmitter is driven to emit the pulsed light. The PFM signal has a frequency that is adjustable to control an average intensity of the pulsed light, the frequency calibrated for a type of the object and an effective range of the photoelectric sensor.