A direct current voltage detector is disclosed including a low-pass filter, an isolating diode and a threshold detector. The circuit is designed to be simple and inexpensive and causes no interference with foreign potential and leakage tests on a telephone line.

A voltage regulator for an AC generator which supplies power to multiple loads at different voltage levels. The magnitude of the multiple voltages and other controlled variables such as per unit current are sensed and individual field currents are generated. A single field current is selected from the individual field currents as a function of the magnitude of a selected voltage and the per unit current and applied to the exciter field of the generator for accurate control of the output voltages...

A voltage regulator for controlling the charging of a battery by the regulation of the output voltage of a generator. In normal operation, the voltage regulator senses the output voltage of the battery through a first sensing line, and enables or disables the energization of the generator field winding if the battery voltage is respectively below or above a desired regulated value. In the event of an interruption in the electrical connection between the battery and generator, a second sensing li...

An MOS low voltage detector circuit includes a comparator which compares an internally generated reference voltage with an internally generated non-linear voltage. Both the reference voltage and the non-linear voltage are derived from a supply voltage, and the comparator generates an output whenever the divided down non-linear voltage falls below the reference voltage. This output is supplied to a series of regularly biased MOS inverter stages which not only amplify the comparator output but als...

A high sensitivity voltage comparator circuit, suitable for integration in monolithic form is disclosed. First and second p-channel field effect transistors, FETs, are arranged as a first cascode amplifier between a relatively positive supply potential and an output node. First and second n-channel FETs are arranged as a second cascode amplifier similar to the first which is connected between a source of relatively negative supply potential and the same output node. Bias potentials are selective...

A voltage monitor is disclosed. The voltage monitor comprises a digital voltmeter for displaying a measured input voltage, and means for converting the varying input voltage of the monitor into a stabilized power supply voltage for the operation of the digital voltmeter. The input voltage is applied to the digital voltmeter through a response time controller providing a long time constant averaging value of input voltage to the digital voltmeter when the input voltage is within a predetermined r...

A voltage regulator is described for use in a television receiver having a horizontal oscillator for exciting a horizontal sweep system and a power source for energizing the receiver. In a receiver which also includes a voltage source derived from the excited sweep system, the regulator preferably includes an input port for receiving current from the power source and a circuit responsive to that current for initially energizing the horizontal oscillator so that the sweep system becomes excited. ...

For a voltage follower unity gain amplifier, used, for instance, as a buffer in a transceiver associated with a data bus, the input signal is fed forward to a comparator (T2-T3) to which the output is also applied. The input is also applied via an amplifier stage (T5-T6) to a transistor (T4) in the commoned circuit of the comparator, which is a long-tailed pair. Thus, with a connection from the output of the circuit which includes another transistor (T9), provides negative feedback round the com...

A voltage comparator for an analog to digital converter is provided which includes several differential amplifier stages connected in cascade that determine the existence of a voltage difference between the two input signals and amplify this voltage difference successively. The comparator further includes offset correction voltage circuits which are connected to each differential amplifier stage and allow for the correction of errors caused by the mismatching of the devices internal to each of t...

A voltage supply circuit for supplying a regulated output voltage the magnitude and temperature coefficient of which can be independently controlled. A pair of transistors and associated circuitry develop a voltage proportional to the .DELTA.V.sub.BE of the two transistors which are operated at different current densities and sets a first current through the collector of a third transistor which is proportional to .DELTA.V.sub.BE having a positive temperature coefficient (TC). A second current p...