A control circuit for SCR multi-standby voltage switching

Abstract

Disclosed is a control circuit for multi standby voltage switching of a silicon controlled rectifier. The control circuit comprises a first silicon controlled rectifier control circuit module (TRIAC1) for outward output, a second silicon controlled rectifier control circuit module (TRIAC2) for outward output, a first isolation controlling relay (JD1), a second isolation controlling relay (JD2) and an ICU detection circuit (DL1). The two silicon controlled rectifier control circuit modules (TRIAC1, TRIAC2) are respectively connected to the two isolation controlling relays (JD1, JD2) so as to provide control signals. The ICU detection circuit (DL1) is respectively connected to the two isolation controlling relays (JD1, JD2) so as to provide alternate time-delay control signals. Output ends of the first silicon controlled rectifier control circuit module (TRIAC1) and the second silicon controlled rectifier control circuit module (TRIAC2), and input ends of the first isolation controlling relay (JD1) and the second isolation controlling relay (JD2) are connected to the same node. A power source of the control circuit realizes ordered work by means of a working relation between voltage differences, and performs isolation control by means of a signal-type relay. Neither a switch from a low voltage to a high voltage or a switch from a high voltage to a low voltage of an output and conversion silicon controlled rectifier will enable the other silicon controlled rectifier to be in an instant conductive state.

Description

technical field [0001] The invention relates to the technical field of electrical equipment, in particular to a control circuit for switching multiple voltages of thyristors. Background technique [0002] Today's thyristor characteristics still have some additional conditions for turning off. This characteristic of thyristor limits the inability to switch at high frequencies. Some traditional electrical control cabinets use relays or contactors for switching, while relays or contactors are used for switching. When the moving contact and the static contact of the device are in contact with a large current, there will be flashover, which is not suitable for frequent work. The other is to replace the relay or contactor with a solid state relay. When a device needs to switch from its original A power supply to B power supply or C power supply to obtain a different voltage power supply in a very short 100mS time (such as UPS), and this type of solid state relay is actually a thyr...

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Problems solved by technology

[0002] Today's thyristor characteristics still have some additional conditions for shutting off. This characteristic of thyristors limits high-frequency switching. Some traditional electrical control cabinets use relays or contactors for switching, and relays or contacts The movable contact and the static contact of the device will flash over when there is a large current contact, which is not suitable for frequent work. The other is to use a solid state relay instead of a relay or contactor. Although the problem of flashover of the contact is solved, it cannot When a device needs to switch its original A power supply to B power supply or C power supply to obtain a different voltage power supply in a short period of 100mS (such as UPS), and this type of solid state relay is actually a thyristor inside. , and the turn-off characteristics of thyristors limit the application in this type of electrical equipment, such as some aging power supply control cabinets used for life cycle acceleration tests and high-current electrical equipment that require rapid switching

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