Abstract: A flame detector for a burner system having a flame during combustion that emits UV radiation, has a low gain UV sensor, a capacitor, a band pass filter receiving the capacitor's signal, and a rectifier receiving the band pass filter signal and providing a rectifier signal. A low pass filter receives the rectifier signal and provides a flame signal as an output whose magnitude is indicative of presence or absence of flame. An optical filter interposed between the UV sensor and the flame and having optical bandpass characteristics attenuating UV radiation outside the wavelength associated with the flame, improves operation.

Abstract: A local station and a remote station are connected by a single pair of conductors. The local station communicates with the remote station by modulating a power supply within the local station which provides power on the conductor pair for operating the remote station. The remote station modulates its impedance, causing a change in current flow on the conductor pair which the local station can detect. In this way both stations can transmit data to each other at the same time and while the local station is providing operating power to the remote station.

Abstract: A power-up/power-down safety switch includes a simple, low-cost circuit having one AND gate, which may be a CMOS IC, one voltage-limiting diode and three resistors. The circuit functions in conjunction with a logic control circuit in a manner which assures that the inhibiting voltage to the logic control circuit V.sub.INH is equal to (or slightly less than) the supply voltage, V.sub.CC (t), until V.sub.CC (t) reaches the minimum required supply voltage for the circuit logic to operate properly. V.sub.INH is then rapidly switched to a low state such that the circuit logic operates without interference. Conversely, when the circuit is turned OFF, the value of V.sub.INH is switched to a high state as soon as the supply voltage reaches the minimum value to operate the logic circuit thereby again causing the logic outputs to go low and that all the drive signals to the power switch are in the OFF state.

Abstract: An electric watthour meter for measuring AC power consumption is disclosed which includes a pair of parallel plate bus bars through which all of the power to be measured is conducted, a magnetoresistive bridge sensor disposed between the pair of bus bars such that the flow of current in either or both of said bus bars produces a corresponding voltage signal from the sensor indicative of the total amount of current flowing in the bus bars and a signal processing system for utilizing the signal from the sensor to produce an output indicative of the total AC power conducted by the bus bars.

Abstract: A phase modulated DC-to-AC or a DC-to-DC power converter utilizes input terminals connected to a source of power and output terminals connected to a suitable load. The transfer of power between the power source and the load or from the load back to the power source is accomplished by electronic switching that is phase displaced controlled in all four quadrants.

Abstract: A voltage isolated gate drive circuit for insulated gate semiconductors utilizes a small, inexpensive pulse transformer to provide a rectangular drive wave form. The small pulse transformer can be operated with an input square wave form at relatively low frequencies, such as 60 hertz, and can be operated from a common power supply with the high voltage supplied to the output field effect transistor.