Comparator applications

About: Comparator applications is a research topic. Over the lifetime, 2518 publications have been published within this topic receiving 26639 citations.

A current comparator bridge for power measurement

Abstract: A current comparator technique for the measurement of sinusoidal ac power at 60 Hz is described. The reference power is that generated by applying the voltage across a 10-kΩ resistor. The voltage itself is measured by comparing it directly to a dc reference with an ac/dc rms voltage comparator. The current is compared with the current comparator to the current in the resistor for the in-phase or active power component, and to the current in a capacitor for the quadrature or reactive power component. Six-digit resolution is provided for both components. The bridge can be operated over a voltage range from 50 to 150 V and a current range from 0.01 to 1 A at any power factor. An auxiliary current transformer provides extension of the current range to 10 A. Comparison measurements with a Drysdale wattmeter used as an ac/dc power transfer standard indicates agreement at unity power factor to within 25 ppm.

Television receiver high voltage generator protection circuit

Abstract: A high voltage generator of a television display is responsive to an alternating voltage, such as a retrace pulse voltage, for developing an ultor voltage at an ultor terminal. A protection circuit for the high voltage generator includes a comparator that develops a television display disabling signal when activated. A circuit that develops a sense voltage representative of the ultor voltage is coupled to an input terminal of the comparator so as to develop the disabling signal when the ultor voltage exceeds a predetermined level. To provide an overload disabling capability, an ultor beam current sensing circuit is coupled to the input terminal of an operational amplifier. The output terminal of the amplifier is coupled to a bias voltage source and to an input terminal of the comparator. When the ultor beam current exceeds a predetermined level indicative of high voltage generator overload operation, the operational amplifier applies the bias voltage to the comparator input to energize the comparator into developing the disabling signal. The magnitude of the bias voltage is such as to activate the comparator in substantial independence of the value of the ultor voltage sense voltage.

Comparator circuit with offset correction

Abstract: A comparator circuit having offset correction circuitry for use in an analog-to-digital converter. The first input of the comparator circuit is periodically connected to ground. The second input of the comparator circuit is connected through a capacitance to ground. The offset voltage generated within the comparator circuit can be considered as being present at the first input. When the offset voltage at the first input is greater than the voltage at the second input a fixed increment of electrical charge is added to the capacitance. When it is less, a fixed increment of electrical charge is subtracted from the capacitance. Thus, increments of electrical charge are accumulated in the capacitance producing a compensating voltage thereacross to correct for the offset voltage.

Comparator offset calibration using unbalanced clocks for high speed and high power efficiency

Abstract: A novel comparator offset calibration using unbalanced clocks is proposed. The new technique avoids loading the comparator core with trimming elements, thus maximising the comparator speed and power efficiency. Simulations show that a comparator utilising the proposed calibration achieves near-native speed and noise performance. It also achieves superior energy-delay-noise product over comparators with conventional calibrations.

Dc/dc converter for suppressing effects of spike noise

Abstract: A comparator 5 changes an output signal from [H] to [L] when a voltage drop VR occurring at a current sensing resistance Rsens becomes greater than a reference voltage VS by a current IL. When the output signal of the comparator 5 is [H], a control circuit 1 outputs a control signal of a duty ratio responsive to the voltage deviation signal outputted from a differential amplification circuit 4 to a switching element 2 . When the output signal of the comparator 5 is [L], the control circuit 1 outputs a control signal, which turns off the switching element 2 , to the switching element 2 . When the switching element 2 is switched, the control circuit 1 connects a filter F of a large time constant to the input side of the comparator 5 by switching off a switching element Tr 1 in a predetermined period of time.