Abstract: A regulated power supply includes a starting circuit that initiates oscillating inverter circuit that generates a high frequency square wave signal that drives a saturable reactor which pulse-width modulates the square wave as a function of a control current through a control winding on the saturable reactor. A protective circuit is provided to sense an output overvoltage condition and inactivate the power supply by terminating the oscillation of the inverter and simultaneously resetting the starting circuit.

Abstract: A signal level indicator comprises first and second voltage comparators responsive to the low and high levels of an input signal, respectively. First and second switching transistors are provided. The base of the first transistor is connected to the output of the first comparator through a first diode, the base of the second transistor being connected directly to the output of the second comparator. First and second light-emitting diodes which emit different colors are respectively energized in response to the conduction of the first and second transistors. The collector of the second transistor is further connected to the cathode of the first diode through a second diode to cause the first diode to switch off to thereby turn off the first transistor in response to the turn-on of the second transistor.

Abstract: A circuit for sensing a plurality of inputs, each of which have a plurality of condition states, and providing a visibly coded output signal to a single indicator lamp, or the like, whereby one may readily determine the various condition states. The circuit is exemplified in an automotive voltage and current sensing system which senses the conditions of normal voltage, overvoltage, undervoltage and battery discharge. The circuit commands a single lamp to be off, to flash rapidly, to light continuously, or to flash slowly in correspondence to the particular sensed condition.

Abstract: A rectifier unit for supplying power to a D.C. load including a transformer having a primary, a secondary and a saturable core, the secondary defining an output section and a control section. A ferroresonance control circuit simulates saturation of the transformer core and includes an electronic switch for controlling the degree of simulated core saturation and thereby regulating the rectifier unit output. Rectifier failure alarm circuitry produces a failure alarm in response to a number of rectifier unit malfunctions. The rectifier failure alarm circuitry is coupled to the ferroresonance control circuitry and comprises a rectifier alarm element operable between the first condition wherein a rectifier failure alarm is produced and a second condition. The failure alarm element is operated from its first condition when the electronic switch minimizes the rectifier system output.

Abstract: An alarm circuit indicating a defect in a car alternator, said circuit comprising a voltage divider formed by two resistors connected between the positive terminal B+ and a negative terminal D- of the alternator, the center point of the voltage divider being connected to the control electrode of a commutation circuit of which the output path is serially connected with a lamp between the terminals of the battery, and rectifier means being provided for preventing the battery to discharge through the voltage divider.

Abstract: A current limiting voltage sensing circuit especially suited as an annunciator input circuit is disclosed. It includes a radiation emitting device circuit, a current limiting circuit for maintaining the current supplied to the voltage sensing circuit at a substantially constant value while supplying the needed current to the radiation emitting device circuit, and a radiation sensitive device circuit coupled to the radiation emitting device and electrically isolated from it for converting from the radiation signal into an electrical signal. In one arrangement, the input to the voltage sensing circuit is a full-wave rectifier so that it can be used for detecting an ac voltage or a dc voltage in either direction.

Abstract: Apparatus is described for monitoring arcing of brushes used in the transfer of current signals to and from the field of a generator. Electrical signals from the brushes, which are applied to the disclosed monitor for analysis, may include brush arcing signals to be monitored and in addition high-amplitude noise spikes in the same frequency band as the brush arcing signals, the noise spikes thus masking accurate detection of low level brush arcing by conventional devices. A two-stage clipping network is provided in the monitor to raise the brush arcing/noise ratio and thus mitigate the masking effect of the noise spikes without loss of a portion of sampling interval during which arcing may occur.