A kind of power signal source Drive Protecting CircuitTechnical field
The present invention relates to a kind of power signal source Drive Protecting Circuits.
Background technique
It in general hardware driving circuit, requires that there is protection circuit, and protects and be divided into hardware protection and software guarantorShield.So-called software protection generally refer to by output end measurement, calculating and analysis, according to the problem of analyzing to originalThe advantages of beginning signal carries out respective handling (such as shutdown signal) etc. to realize, software protection be can analyze it is thinner, veryWhat more hardware can not react can particularly point out (such as THD) in software protection, but the disadvantage of software protection is exactly to ringIt answers speed slow, belongs to post-processing, protect evening after hardware has damaged sometimes again, therefore protecting effect is limited.And hardware protection it is general there are many kinds of, have output end protected, have and front end protected.Since driving exportsEnd has the features such as voltage is high, and power is big, therefore is the most weak place of entire circuit link, and most faults are equalOccur herein.Though power amplifier output end is most easily broken down, " treating the head when the head aches, foot pain doctor foot " can not reach pre- sometimesThe effect of phase.
Summary of the invention
In order to overcome the deficiencies of the prior art, the present invention provides a kind of power signal source Drive Protecting Circuit.
Technical solution provided by the invention are as follows:
It is defeated including power supply unit, signal synthesis unit, overrun testing unit, driving unit, feedback unit and isolation boostingUnit out；
Said supply unit is used to extraneous high AC voltage being rectified into high direct voltage voltage source and be depressured as low pressureDC voltage source, the low-voltage DC potential source control on-off by optical coupling unit；The low-voltage DC potential source is for controllingThe control triode of the driving unit；
The signal synthesis unit is used to synthesize extraneous input signal and feedback signal and control the double of transport and placing devicePolarity power, the bipolar power supply of the transport and placing device by driving unit with the signal of the positive-negative half-cycle of driving power signal source,The output information of the transport and placing device is sent to overrun testing unit simultaneously, and whether the overrun testing unit is transfinited by detection numberControl the optical coupling unit in power supply unit；
The driving unit is used to the composite signal of transport and placing device being driven to high-power signal source, and the driving unit includesControl triode (Q1 and Q2), overload protection triode (Q3 and Q4) and driving metal-oxide-semiconductor (Q5 and Q6)；The control triodeBase stage controls on-off by the optical coupling unit in said supply unit, and controls driving MOS according to the sampling voltage of divider resistanceThe grid of pipe, the control transistor emitter are used to control the power supply and output signal of signal synthesis unit transport and placing device, current collectionPole is supplied to the signal source of driving unit；The overload protection triode and corresponding resistor constitute the overload of driving metal-oxide-semiconductor togetherCircuit is protected, driving metal-oxide-semiconductor is used for weak signal power amplification and exports to isolation boosting output unit.
The feedback unit is used to detect the sampled signal of the secondary side of the isolation boosting output unit, and sampling is believedNumber it is sent to the signal synthesis unit；
The isolation boosting output unit is used to the power signal source that driving unit is sent boosting to the higher of secondary sideThe power signal of voltage.
Preferably, said supply unit, signal synthesis unit, driving unit and feedback unit are using the double electricity of SymmetricalSource design.
Preferably, high direct voltage voltage source is passed through sata power resistance, zener diode and filter by said supply unitWave capacitor is converted to low-voltage DC potential source, and the low-voltage DC potential source controls on-off, the optocoupler by optical coupling unitUnit is closed to be controlled by the optical coupling unit in overrun testing unit.
Preferably, the control information of the optical coupling control unit include output transfinite protection, temperature over-range protection andThe control point of software protection.
Preferably, the positive ends of the driving unit control triode by NPN type, positive-negative-positive overload protection triode,P-channel drives metal-oxide-semiconductor, and sample resistance and current-limiting resistance are constituted；It is then overloaded by positive-negative-positive control triode, NPN type at negative polarity endTriode, N-channel is protected to drive metal-oxide-semiconductor, sample resistance and current-limiting resistance are constituted；
The base stage of the control triode is controlled by optical coupling unit, emitting stage and the signal synthesis unit transport and placing devicePower supply is connected；Positive and negative terminal (± 170V) and sample resistance, the emitter of overload protection triode, the current-limiting resistance phase of high voltage power supplyEven；High voltage power supply is connected by sample resistance with the collector for controlling triode simultaneously, and passes through current-limiting resistance and overload protectionThe base resistance of triode is connected, high voltage power supply divided by sample resistance after also with the pole G and overload protection three that drive metal-oxide-semiconductorThe collector of pole pipe is connected；
The pole S of the driving metal-oxide-semiconductor is connected by current-limiting resistance with high voltage power supply, and the sampled signal of current-limiting resistance is connectedIt is connected to the base resistance of overload protection triode.
Preferably, the transport and placing device of the feedback unit receives the resistance point of the secondary side of the isolation boosting output unitSignal is pressed, the output signal of feedback unit transport and placing device is used to synthesize drive by the amplifier of signal synthesis unit with extraneous input signalSignal needed for moving cell；
Preferably, the low-pressure direct that the high direct voltage voltage source current limliting decompression of said supply unit general ± 170V is ± 15VGalvanic electricity potential source, and pass through the control triode that this bipolarity low-voltage DC potential source controls positive and negative terminal in driving unit respectively.
It preferably, further include overrun testing unit, the overrun testing unit is used to control the light of said supply unitCoupling diode, when detecting overload signal, the overrun testing unit control said supply unit power-off.
Beneficial effects of the present invention:
Power signal source Drive Protecting Circuit of the invention is using the transport and placing device in signal synthesis unit as core, by transport and placing deviceAfter the external signal of signal and input that feedback unit is detected from secondary side is synthesized, pass through signal synthesis unitCurent change in bipolar power supply controls the I of triode to control in driving unitCE, then pass through the control of divider resistance sampled signalSystem driving metal-oxide-semiconductor.Entire circuit system has multiple protective.When the output overvoltage of isolation boosting output unit, pass through feedbackUnit feeds back to signal synthesis unit, and causing the amplifier in synthesis unit to export transfinites, and overrun testing unit detects the letter that transfinitesBy the power supply of amplifier in optical coupling unit cut-off signals synthesis unit after number, the driving metal-oxide-semiconductor of driving unit is simultaneously turned off；WhenWhen the output overcurrent of isolation boosting output unit, by transformer feedback to primary side and primary side current is caused to transfinite, passed throughIt send after current-limiting resistance sampling to the base stage of overload triode, thus the V of the metal-oxide-semiconductor of cutting driving at onceGSSignal, i.e. shutdown drivingMetal-oxide-semiconductor.By this double hardware protection being exceedingly fast, the high reliability and high stability of whole system can be fully ensured that.
Detailed description of the invention
Fig. 1 is the schematic block circuit diagram of power signal source Drive Protecting Circuit of the invention；
Fig. 2 be the signal synthesis unit of power signal source Drive Protecting Circuit of the invention, driving unit, feedback unit andThe circuit diagram of isolation boosting output unit；
Fig. 3 is the power supply unit of power signal source Drive Protecting Circuit of the invention and the circuit diagram of overrun testing unit.
Specific embodiment
The present invention will be further explained below with reference to the attached drawings；
A kind of power signal source Drive Protecting Circuit, as shown in Figure 1, Figure 2 and Figure 3, including the synthesis of power supply unit 1, signalUnit 2, driving unit 3, feedback unit 4, isolation boosting output unit 5 and overrun testing unit 6；Said supply unit 1, signalSynthesis unit 2, driving unit 3 and feedback unit 4 are designed using Symmetrical dual power supply.
As shown in figure 3, high direct voltage voltage source is passed through sata power resistance, zener diode and filter by said supply unitWave capacitor is converted to low-voltage DC potential source；The low-voltage DC potential source controls on-off by optical coupling unit；The low-pressure directGalvanic electricity potential source is used to control the control triode (i.e. Q1 and Q2) of the driving unit；The optical coupling unit is by overrun testing listThe output signal control of member；The signal of the overrun testing unit is from the output of amplifier in the signal synthesis unit.InstitutePower supply unit is stated by high voltage supply voltage ± 170V by generating after sata power resistance, zener diode and filter capacitorThe supply voltage of ± 15V, i.e. G+ and G-, G+ and G- herein are controlled by optical coupling unit U4 and U5 respectively, when U4 and U5 is connectedWhen, G+ and G- can become 0V.G+ and G- is respectively used to control the base stage of triode Q1 and Q2 in control driving unit, as G+ andWhen G- can become 0V, the cut-off of Q1 and Q2 triode, flowing through the electric current on divider resistance R14 and R15 is 0, therefore R14 and R15On voltage be also 0, cause Q5 and Q6 to be also switched off, output close.When U4 and U5 are closed, G+ and G- be respectively+15V and-The power supply and output of 15V, amplifier U1 will be in normal condition, be become by the electric current of amplifier bipolar power supply in signal synthesis unitChange, to control the I of Q1 and Q2CEElectric current, the output electricity of control driving metal-oxide-semiconductor (Q5 and Q6) after being sampled by divider resistancePressure.Optical coupling unit U6, U7, U8 of second optical coupling control unit respectively correspond output transfinite protection, temperature over-range protection andSoftware protection, temperature over-range protection and software protection mode and the output protected mode that transfinites are identical, are all by control G+ and G-Power supply realize.Optical coupling unit U4 and U5 are series connection, to ensure that ± 15V is simultaneously turned off or opened.Second optical coupling controlConnect after optical coupling unit U6, U7, U8 of unit processed is in parallel with U4 and U5, if such U6, U7, U8 have all the way control instruction arriveCome, G+ and G- will be 0.The overrun testing unit 6 is used to control the optical coupling diode of said supply unit, when detectingWhen overload signal, overrun testing unit control said supply unit power-off, wherein the amplifier U3A of overrun testing unit andU3B derives from the signal of signal synthesis unit transport and placing device for controlling U6, the input signal of U3A.
The main component of the signal synthesis unit is transport and placing device U1, is detected feedback unit from secondary side by transport and placing deviceSignal FB+ and input external signal IN_SIG synthesized after, by the bipolar power supply of signal synthesis unitCurent change controls the I of triode to control in driving unitCE, then pass through divider resistance sampled signal control driving metal-oxide-semiconductor.It is defeatedWhen normal out, protection circuit does not work, and the nominal voltage of at this moment T1 grade of transformer output is that 380V (is lifted here with 380VExample).
When isolating transformer output earth short circuit, since immediate current is very big, primary side is fed back to by transformer T1Electric current is also very big, so that protecting circuit to permit more than the overload current centered on Q3 and Q4 by the electric current moment in Q5 and Q6Perhaps threshold value, therefore moment Q5 and Q6 is at off state；Simultaneously after secondary terminal shortcircuit, secondary end passes through electric resistance partial pressure(or mutual inductor sampling current) resulting negative-feedback signal FB+ moment becomes 0, and the negative terminal of U1 is fed back to by amplifier U2, so thatThe output signal SIG_WARN moment of U1 is more than the signal of 6V or so, and SIG_WARN signal is led by amplifier U3A and U3B outputLight passing coupling U6, so that G+ and G- are closed, while Q1 and Q2 cut-off, amplifier U2 short of electricity, and because Q1 and Q2 ends, metal-oxide-semiconductor Q5 and Q6VGSSignal is 0, Q5 and Q6 is also at off state, to realize the hardware protection process of entire driving circuit.
Likewise, isolating transformer secondary side output at this time existed when isolating transformer output occurs across mutually short circuitSituation is pressed, signal synthesis unit is fed back to by feedback unit, causing the amplifier in synthesis unit to export transfinites, overrun testing listMember detects to transfinite after signal through the power supply of amplifier in optical coupling unit cut-off signals synthesis unit, simultaneously turns off driving unitDriving metal-oxide-semiconductor；In addition it when across mutually short-circuit over-voltage, generally synchronizes and overcurrent occurs, by transformer feedback to primary side and leadIt causes primary side current to transfinite, is sent after being sampled by current-limiting resistance to the base stage of overload triode, thus the metal-oxide-semiconductor of cutting driving at onceVGSSignal, i.e. shutdown driving metal-oxide-semiconductor.
It is transfinited by overload protection and over-voltage and protects this double hardware protection being exceedingly fast, can fully ensure that the height of whole systemReliability and high stability.