A supply identifier takes precise decision on the range of the external supply to manage a proper internal supply to the core of the IC by controlling a regulator or a switch connected to external supply. This supply identifier defers the decision until everything that influences the decision settles after power-up, then makes a decision only once depending on the external supply range and switches itself off, keeping the decision stored, to avoid noise-induced wrong behavior and to reduce power...

The method and circuit arrangement both minimize stray electromagnetic interference in an electronic circuit, in which symmetric measurement signals are evaluated. Both inputs (InP, InM) of an evaluation circuit (2) are provided with a bank of switchable capacitors (C.sub.z) individually or in groups, which are connectable with the respective inputs. A predetermined interference signal is applied to the respective inputs (InP, InM) and individual ones or groups of the switchable capacitors (C.su...

A circuit for establishing and controlling a synchronous relationship between the voltages of two independently energized a-c sources. Two a-c voltages are applied in switching control relationship to respective inputs of a phase comparator circuit. The comparator circuit generates a pulse train having a duty cycle which is a substantially linear function of the phase angle between the voltages of the two a-c sources. A reference pulse train having a fixed duty cycle is subtracted from the varia...

In a control system for automatically synchronizing and effecting connection of a power generator to an operating power line, means are provided for sensing differences in certain frequency and phase parameters existing between the output signal of the power generator and the signal on the operating power line and thereafter generating control signals for affecting the speed of the power generator to cause any differences existing between those frequency and phase parameters to fall within defin...

An electrical power generation and distribution system with two alternating current generators each powered by a variable speed engine through a constant speed drive. Each generator has a constant speed drive control with a phase comparator and a summing integrator to maintain phase synchronism with a reference signal. The generators are connected in parallel with each other or with an external power source, through switches actuated by the output of the phase comparator. The switches are closed...

A synchronizing check relay is used in an electrical transmission network for controlling a circuit breaker to interconnect first and second transmission lines to establish power flow therebetween and includes an input circuit for receiving signals from first and second transmission lines. A phase difference generator generates a phase difference signal proportional to a phase difference between said signals from said first and second transmission lines. A phase difference comparator receives th...

A synchronizer for matching the voltage and frequency of a relatively lower rating alternating current generator to those of an alternating current bus or line to which the generator is to be connected. A circuit breaker is interposed between the generator and bus to complete the circuit between them upon command from the synchronizer. The voltage and frequency on both sides of the circuit breaker are sensed and supplied to the synchronizer circuit in signal form. The voltages and frequencies ar...

An electronic circuit for use with an exhaustible power source and load such as a light bulb, includes a microchip with an input that transmits a signal to the microchip when the load is activated or deactivated. The input does not form a serial link between the power source and the load. The power switch, by on/off switching, controls energy flow from the power source to the load. The electronic circuit has an automatic delayed shut-off function for the load and, a find-in-the-dark indicator an...

A chain reaction control circuit for parallel power supply provides greater power without changing the design of the original power supply structure. It includes a control unit to receive a first power actuation signal output from a power actuation unit, then output multiple sets of second power actuation signals to parallel power supplies. The multiple power supplies that are coupled in parallel receive the second power actuation signals and transform electric power simultaneously, then output ...

A low cost differential voltage limiter circuit provides a feedback to regulate a voltage output of a voltage source. In one embodiment, the limiter circuit includes a transistor coupled to outputs of first and second voltage sources. If a differential voltage between the two sources exceeds a predetermined threshold, the output voltage of the higher source is reduced. In one embodiment, a PNP transistor is used to regulate the high voltage source.