Abstract: An apparatus and methodology for operating an automatic darkening filter (ADF) eye protection device alternately applies an operating voltage to a pair of control terminals of an ADF device circuit in a continuing sequence, where a first polarity voltage is applied to the pair of terminals and then reversed. A delay period is provided between application of the alternating polarities. In some embodiments ground potential is applied to both terminals of the pair of terminals during the delay period.

Abstract: Disclosed is an apparatus and methodology for operating an automatic darkening filter (ADF) eye protection device. An operating voltage is alternately applied to a pair of control terminals of an ADF device circuit in a continuing sequence where a first polarity voltage is applied to the pair of terminals and then reversed. A delay period is provided between application of the alternating polarities. In some embodiments ground potential is applied to both terminals of the pair of terminals during the delay period.

Abstract: An auto darkening eye protection device including a shutter assembly, a light sensing circuit, a control circuit and a power source. The shutter assembly is adjustable to a plurality of shade levels. The phototransistor of the light sensing circuit senses light from a welding arc and provides an output of the light sensing circuit indicative of the shade level at which the shutter assembly should be operated. The phototransistor is configured for surface mount and has an external base connection connected to the base of the phototransistor. The control circuit is configured to receive the output from the light sensing circuit and provide a drive signal to the shutter assembly responsive to said output, drives the shutter assembly to one of said plurality of shade levels.

Abstract: An auto darkening eye protection device including a shutter assembly, a light sensing circuit, a control circuit and a power supply source. The shutter assembly is adjustable to a plurality of shade levels. The phototransistor of the light sensing circuit senses light from a welding arc and provides an output of the light sensing circuit indicative of the shade level at which the shutter assembly should be operated. The phototransistor is configured for surface mount and has an external base connection connected to the base of the phototransistor. The control circuit is configured to receive the output from the light sensing circuit and provide a drive signal to the shutter assembly responsive to said output, drives the shutter assembly to one of said plurality of shade levels.

Abstract: A sensor circuit for detecting the occurrence of welding is disclosed. The sensor circuit uses a phototransistor operative to receive a light input and produce an output representative thereof. A resistor is coupled between the phototransistor's base and emitter to control the phototransistor's response to low intensity and high intensity light. An amplifier may be coupled to the output of the phototransistor so as to provide a gain for the output of the phototransistor; and feedback means may coupled to the phototransistor to bias the phototransistor, the feedback means comprising a resistor capacitor circuit for following the output of the phototransistor, a feedback transistor to provide a feedback signal to the phototransistor, and a resistor coupled between the base and the emitter of the phototransistor. Preferably the phototransistor is a planar phototransistor having a surface mount.

Abstract: A sensor circuit for detecting the occurrence of welding is disclosed. The sensor circuit uses a phototransistor operative to receive a light input and produce an output representative thereof. A resistor is coupled between the phototransistor's base and emitter to control the phototransistor's response to low intensity and high intensity light. An amplifier may be coupled to the output of the phototransistor so as to provide a gain for the output of the phototransistor; and feedback means may coupled to the phototransistor to bias the phototransistor, the feedback means comprising a resistor capacitor circuit for following the output of the phototransistor, a feedback transistor to provide a feedback signal to the phototransistor, and a resistor coupled between the base and the emitter of the phototransistor. Preferably the phototransistor is a planar phototransistor having a surface mount.

Abstract: A sensor circuit for detecting the occurrence of welding is disclosed. The sensor circuit uses a phototransistor operative to receive a light input and produce an output representative thereof. A resistor is coupled between the phototransistor's base and emitter to control the phototransistor's response to low intensity and high intensity light. An amplifier may be coupled to the output of the phototransistor so as to provide a gain for the output of the phototransistor; and feedback means may coupled to the phototransistor to bias the phototransistor, the feedback means comprising a resistor capacitor circuit for following the output of the phototransistor, a feedback transistor to provide a feedback signal to the phototransistor, and a resistor coupled between the base and the emitter of the phototransistor. Preferably the phototransistor is a planar phototransistor having a surface mount.

Abstract: A weightbridge with pivotal supporting system. The weightbridge may be of either electronic or mechanical measuring type. In an electronic weightbridge embodiment, the supporting system is also a connecting system for adjacent deck sections. One of the deck sections has pairs of spaced plates extending therefrom with a pin attached thereto. A load cell is mounted on a base below the plates. The pins on the plates are interconnected with ends of the load cell by a pair of links. Sleeves are positioned on the pins and are engaged by the links. An adjacent deck section has plates extending therefrom, each plate having a notch therein for pivotal engagement with the pins. The deck sections may be locked against pivotation if desired. In a mechanical weightbridge embodiment, a plate extends transversely from an end of a deck section and has a pin with opposite ends extending therefrom. A beam is pivotally mounted adjacent the deck section and has a support pin extending therefrom.