A power contact fault clearing device includes a first pair of terminals adapted to be connected across a first set of switchable contacts, and a second pair of terminals adapted to be connected across a second set of switchable contacts. The second set of switchable contacts coupled to an arc suppressor. A current sensor is adapted to be connected between a power load and the second set of switchable contacts. The current sensor is configured to measure a power load current associated with the power load. A controller circuit is operatively coupled to the current sensor and the first and second pairs of terminals. The controller circuit is configured to detect a fault condition based at least on the power load current, and sequence deactivation of the first set of switchable contacts and the second set of switchable contacts based on the detected fault condition.

Device, circuit, system, and method for contact sequencing are discussed. An electrical circuit includes a first pair of terminals adapted to be connected across a first set of switchable contacts, and a second pair of terminals adapted to be connected across a second set of switchable contacts that are coupled to an arc suppression circuit. A controller circuit is coupled to the first and second pairs of terminals and is configured to sequence activation or deactivation of the first and second sets of contacts based on a contact control signal. A first power switching circuit is coupled to the first pair of terminals and the controller circuit. The first power switching circuit is configured to switch power from an external power source and to trigger the activation or the deactivation of the first set of switchable contacts based on a first logic state signal from the controller circuit.

A power contact EoL predictor includes a pair of terminals adapted to be connected to a set of switchable contact electrodes of a power contact; a power switching circuit configured to trigger activation of the contact electrodes based on a first logic state signal or deactivation based on a second logic state signal; a contact separation detector determining a time of separation of the switchable contact electrodes of the power contact during the deactivation, and a controller configured to generate the second logic state signal to trigger the deactivation, and determine a stick duration associated with the set of switchable contact electrodes. The stick duration is based on a difference between a time the second logic state signal is generated and the time of separation during the contact cycle. The controller generates an EoL prediction for the contact electrodes based on the determined stick duration for multiple contact cycles.

A semiconductor device disposed on a primary side of a system generating a secondary side voltage in an insulated form from a primary side voltage includes: a signal generation circuit configured to generate a voltage information signal for transmitting voltage information based on the primary side voltage to a secondary side of the system in the insulated form.

A switch controls current to be supplied to an inductive load when turned on. A clamp circuit clamps a flyback voltage resulting from turning off the switch. The clamp circuit has a first clamping voltage responsive to the switch being turned off, and has a second clamping voltage, higher than the first clamping voltage, responsive to a current level through the inductive load being lower than a predetermined current level. That ensures that as the current comes down to levels required to break contact, the clamp voltage is increased to speed the collapse of the magnetic field when needed to minimize contact wear by maintaining armature momentum.

A modulator includes: a high voltage transformer transforming a voltage supplied through a primary side and a secondary side to apply a current pulse to a driving device; a bipolar pulse generator applying a magnetizing pulse and a main pulse to a connection line connected to the primary side of the high voltage transformer; and a timing controller controlling a time difference of applying the magnetizing pulse and the main pulse, wherein the bipolar pulse generator includes a magnetizing pulse generation unit generating the magnetizing pulse by using positive power, and a main pulse generation unit generating a negative pulse by using negative power. Also, the modulator includes a pulse waveform controller in which a plurality of unit modules of the same structure is disposed in series through a small transformer on the secondary side of the high voltage transformer. These two configurations may independently control the magnitude and the waveform of the current pulse of the high voltage, respectively and realize simultaneously two functions.

A system includes a dry contact with a first pair of switchable electrodes, a wet contact with a second pair of switchable electrodes, an arc suppressor operatively, and a controller circuit operatively coupled to the arc suppressor and the first and second pairs of switchable electrodes. The controller circuit is configured to detect a failure of the wet contact and determine a stick duration associated with the first pair of switchable electrodes. The controller circuit generates a health assessment for the first pair of switchable electrodes based on a comparison of the determined stick duration with an average stick duration associated with a window of observation.

Disclosed by present disclosure are a Darlington transistor drive circuit, a Darlington transistor drive method and a switching power supply management chip. In this embodiment, the Darlington transistor is driven sectionally. At the beginning of the switching-on cycle, the driving of the primary transistor is not started temporarily, instead the drive source is used to drive the secondary transistor. After the secondary transistor is completely switched on, the drive source of the secondary transistor is switched off and the drive source of the primary transistor is switched on to drive the Darlington transistor. The primary and secondary transistor have been completely switched on, and the drive current of the secondary transistor never depend on the primary transistor, so the voltage at the input terminal of the secondary transistor can be smaller than the voltage at the control terminal of the secondary transistor. Such that the switching-on power loss is reduced.

A switch controls current to be supplied to an inductive load when turned on. A clamp circuit clamps a flyback voltage resulting from turning off the switch. The clamp circuit has a first clamping voltage responsive to the switch being turned off, and has a second clamping voltage, higher than the first clamping voltage, responsive to a current level through the inductive load being lower than a predetermined current level. That ensures that as the current comes down to levels required to break contact, the clamp voltage is increased to speed the collapse of the magnetic field when needed to minimize contact wear by maintaining armature momentum.

An electronic switch for switching a load, having a current path which runs between an operating voltage connection and a load connection and to which a power transistor and a current sensor sensing the load current are connected, and having a control or regulating device which controls the power transistor on the basis of the load current, wherein the control or regulating device is connected to the secondary circuit of a converter circuit having a transformer, the primary circuit of which is connected to the operating voltage connection via a controlled switch arrangement.