CN105141120A

CN105141120A - Magnetic isolation power-on circuit

Info

Publication number: CN105141120A
Application number: CN201510670600.3A
Authority: CN
Inventors: 彭立盛; 王卫国; 张俊峰
Original assignee: Lanzhou Institute of Physics of Chinese Academy of Space Technology
Current assignee: Lanzhou Institute of Physics of Chinese Academy of Space Technology
Priority date: 2015-10-16
Filing date: 2015-10-16
Publication date: 2015-12-09

Abstract

The invention discloses a magnetic isolation power-on circuit, which can realize a non-instruction bus pulse instruction small signal isolation power-on function of a DC-DC power supply, cut off a starting circuit after a pulse instruction disappears, reduce product power consumption, improve product efficiency, reduce oscillation sources and improve product EMC performance. A high-level signal of the pulse instruction is converted into a high-frequency oscillation signal via a self-excitation oscillation circuit, isolation transmission is carried out via a transformer, and isolation transmission of weak signals is realized. Meanwhile, a control circuit is designed, signals after isolation transmission are converted into high-current signals, a field effect transistor VM2 is adopted to control on and off of an RCC oscillation circuit, and thus the non-instruction bus pulse instruction small signal isolation power-on function of the DC-DC power supply is further realized.

Description

A kind of Magnetic isolation boot-strap circuit

Technical field

The present invention relates to tiny signal isolation transmission technique field, be specifically related to a kind of Magnetic isolation boot-strap circuit.

Background technology

Spacecraft needs a large amount of on/off circuits, provides command bus and switching on and shutting down order line under normal circumstances.When not providing command bus, switching on and shutting down command signal linear heat generation rate is usually larger, to drive the electronic devices and components such as relay, or does not need isolation.When requiring without command bus, and during start-up command power very little (10V ~ 12V is less than 1mA), current on/off circuit can not meet technical requirement.Be less than under 1mA small-signal, usual available electromagnetic relay cannot drive, and does not have command bus, and amplifying circuit cannot be adopted to drive specially electromagnetic relay, and optocoupler due to Flouride-resistani acid phesphatase require cannot select.

Summary of the invention

In view of this, the invention provides a kind of Magnetic isolation boot-strap circuit, what can realize DC-DC power source isolates power up function without command bus pulse command small-signal, and start-up circuit can be closed after pulse command disappears, reduce product power consumption, improve product efficiency, simultaneously, decrease oscillation source, improve product E MC performance.

Magnetic isolation boot-strap circuit of the present invention, comprises self-maintained circuit, transformer T1, field effect transistor VM2 and RCC oscillating circuit, and wherein, self-maintained circuit is used for changing start-up command signal into high-frequency oscillation signal; Transformer T1 is used for high-frequency oscillation signal isolation to be transferred to field effect transistor VM2, field effect transistor VM2 is according to the unlatching of high-frequency oscillation signal control RCC oscillating circuit or closedown, after RCC oscillating circuit is opened, busbar voltage is carried out isolation to transform and outwards power supply, RCC oscillating circuit stops power supply after cutting out;

Wherein, the switching device of RCC oscillating circuit is triode VQ1; The winding coil n1 on the main limit of self-maintained circuit, transformer T1 is connected between start-up command input and instruction loop line successively, resistance R104 is connected between start-up command input and self-maintained circuit, and electric capacity C101 is connected between self-maintained circuit and transformer T1; Resistance R101, resistance R102, resistance R103 are connected between bus input and bus loop line successively; Winding coil n2, the rectifier diode VD15 of voltage-stabiliser tube VZ2, transformer T1 secondary are connected in parallel on the two ends of resistance R103 after connecting successively; Filter capacitor C102 is connected between the anode of voltage-stabiliser tube VZ2 and the negative electrode of rectifier diode VD15, forms current rectifying and wave filtering circuit with rectifier diode VD15; The grid of field effect transistor VM2 is connected with the negative electrode of voltage-stabiliser tube VZ2, and field effect transistor VM2 grid voltage is determined by the voltage stabilizing value of voltage-stabiliser tube VZ2; The drain electrode of field effect transistor VM2 connects the base stage of the triode VQ1 in RCC oscillating circuit, and field effect transistor VM2 source electrode connects bus loop line.

Beneficial effect:

The present invention is neither providing command bus, and control command signal input power very little when, achieve the isolation transmission of pulse tiny signal, simultaneously, by controlling the conducting of transistor base parallel field effect pipe and the vibration ending to come control RCC, realize opening and shutting off of RCC oscillating circuit.This circuit both achieved DC-DC power source without command bus power up function, again pulse command disappear after close start-up circuit, reduce product power consumption, improve product efficiency, meanwhile, decrease oscillation source, improve product E MC performance.

Accompanying drawing explanation

Fig. 1 is circuit diagram of the present invention.

Embodiment

To develop simultaneously embodiment below in conjunction with accompanying drawing, describe the present invention.

The invention provides a kind of Magnetic isolation boot-strap circuit, by self-maintained circuit, the high level signal of pulse command is converted to high frequency oscillation signal, carry out isolation transmission by transformer, achieve the isolation transmission of tiny signal.Simultaneously, control circuit is designed, signal after isolation transmission is converted to the signal switching big current, what achieve DC-DC power source isolates power up function without command bus pulse command small-signal, closes start-up circuit again, reduce product power consumption after pulse command disappears, improve product efficiency, meanwhile, decrease oscillation source, improve product E MC performance.

As shown in Figure 1, the winding coil n1 on the main limit of resistance R104, self-maintained circuit, electric capacity C101, transformer T1 is connected between start-up command input and instruction loop line circuit of the present invention successively; Wherein, self-maintained circuit is made up of resistance R100A, resistance R100, electric capacity C100 and reverser D1, and start-up command signal is generally level or is pulse signal, and start-up command signal is changed into high-frequency oscillation signal by this self-maintained circuit; High-frequency oscillation signal is passed to transformer secondary through transformer T1.Resistance R104 is connected in self-maintained circuit, ensures that start-up command input impedance meets small area analysis index.Resistance R101, resistance R102, resistance R103 are connected between bus input with bus loop line successively, and voltage-stabiliser tube VZ2, transformer T1 winding coil n2, diode VD15 are in parallel with resistance R103 after connecting successively; Filter capacitor C102 is connected between the anode of voltage-stabiliser tube VZ2 and the negative electrode of rectifier diode VD15, and filter capacitor C102 and diode VD15 forms current rectifying and wave filtering circuit; The grid of VM2 is connected with the negative electrode of VZ2, and VM2 grid voltage determines primarily of VZ2 voltage stabilizing value; The drain electrode of VM2 connects the base stage of the triode VQ1 in RCC oscillating circuit, and VM2 source electrode connects bus loop line.

After bus powers up, voltage is added to the grid of field effect transistor VM2 by R101, R102, R103, and VM2 drain electrode and source class conducting, VQ1 base stage shorted to earth, RCC oscillating circuit can not vibrate.Voltage-stabiliser tube VZ1 both can prevent RCC from shifting to an earlier date starting of oscillation, again for VM2 grid is provided with suitable level.D1 is inverter, and it and resistance R100, R100A, electric capacity C100 form self-maintained circuit, and the high level signal of input pulse is converted to high-frequency oscillation signal.Resistance R104 is current-limiting resistance, ensures that instruction input current is no more than 1mA.T1 is transformer, and electric capacity C101 is capacitance, and VD15 is rectifier diode, and C102 is filter capacitor, and high-frequency signal isolation is transferred to transformer secondary by them, and rectifying and wave-filtering.After pulse command arrives, signal high level is converted to high-frequency oscillation signal by self-maintained circuit, through transformer, is then added in resistance R103 two ends after rectifying and wave-filtering rectification.Because this voltage and the original both end voltage of R103 are reverse, R103 both end voltage is reduced to below 2V, and VM2 ends, the starting of oscillation of RCC oscillating circuit, DC-DC power source work.DC-DC power source continuous firing is ensured by self holding circuit after DC-DC power source work.At the end of pulse command, signal high level disappears, the conducting of VM2 drain-source level, RCC circuit failure of oscillation.

This circuit has been applied in spacecraft DC-DC power source, can be Absorbable organic halogens work within the scope of-35 DEG C ~ 70 DEG C in ambient temperature.

In sum, these are only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. a Magnetic isolation boot-strap circuit, is characterized in that, comprises self-maintained circuit, transformer T1, field effect transistor VM2 and RCC oscillating circuit, and wherein, self-maintained circuit is used for changing start-up command signal into high-frequency oscillation signal; Transformer T1 is used for high-frequency oscillation signal isolation to be transferred to field effect transistor VM2, field effect transistor VM2 is according to the unlatching of high-frequency oscillation signal control RCC oscillating circuit or closedown, after RCC oscillating circuit is opened, busbar voltage is carried out isolation to transform and outwards power supply, RCC oscillating circuit stops power supply after cutting out;