CN1373632A - Voltage-limiting current-stabilizing device for fluorescent lamp of aircraft - Google Patents

Abstract

A voltage-limited current stabilizer for the fluorescent lamp of aircraft is characterized by use of dual close-loop controllers for optimal control of start voltage and tube current, and the combined lighting controls of aircraft.

Description

Voltage-limiting current-stabilizing device for fluorescent lamp of aircraft

Affiliated technical field:

Switching Power Supply

Prior art:

Same device adopts combination binary channels HF switch control circuit, realizes fluorescent tube starting resistor and current controlling by changing pulse amplitude.

Goal of the invention:

1, adopt two independently close loop control circuits, amplitude by changing pulse and frequency realize the Optimal Control to fluorescent tube starting resistor and operating current respectively, improve functional reliability;

2, adopt various measures to satisfy the instructions for use of aircarrier aircraft to device fail safe and reliability.Technical scheme:

1, operation principle (see figure 1):

Bridge rectifier (QZ) exchanges input with aircraft and is transformed into direct current output, increases to the high voltage direct current output of qualification through boost switching circuit (KS).Provide the stable unidirectional rectangular pulse electric current of low frequency by switch current stabilization circuit (KW) to bridge inverter main circuit (QN), be transformed into the positive and negative two-way rectangular pulse electric current that alternately passes through fluorescent tube (YD) by bridge inverter main circuit, make fluorescent tube under the low-frequency ac state, light work.

(1) fuse (RD):

When aircraft input current during greater than setting, fuse cuts off the AC power input, stops voltage-limiting current-stabilizing device (abbreviation device) work.

(2) input radio frequency filter (SL):

Main restraining device is to the radio frequency conducted interference of power supply on the machine, and also suppressing aircraft power supply radio frequency conducted interference simultaneously influences device.

(3) bridge rectifier (QZ):

Bridge rectifier obtains the output of sinuous pulsation voltage with 115 volt of 400 hz AC power supply input of aircraft through full-wave rectification.

(4) boost switching circuit (KS):

Function: will become 650 volts of high voltage direct current outputs from the sinuous pulsation voltage transformation of bridge rectifier, and voltage stabilizing.

Constitute: by the control module of boosting (U1), field effect transistor switch pipe (Q1), inductance (L1), diode (D1), electric capacity (C1), and divider resistance (R1, R2, R3, R4, R5) form.

Principle: the control module of boosting (U1) is pressed the break-make of the FEEDBACK CONTROL switching tube (Q1) of output voltage, exports high voltage direct current by the energy storage of boost inductance (L1) by diode.Electric capacity (C1) plays energy storage and level and smooth filter action.

The break-make of switching tube is determined by current threshold.Sinuous pulsation voltage (the u of current threshold after by full-wave rectification _l) and output voltage feedback (u _f) determine jointly with respect to the deviation signal of reference voltage.When the switching tube electric current equaled current threshold, the control module of boosting was turn-offed switching tube, treated to connect once more when the inductance winding current is zero switching tube.Higher when output voltage, output voltage feedback is in a ratio of the overgauge signal with reference voltage, current threshold is reduced and switching tube output peak current descends thereupon, causes that the energy storage of inductance winding reduces, output voltage descends.Otherwise output voltage is on the low side, and the output voltage feedback also produces the minus deviation signal, and current threshold is increased, thereby makes output voltage keep stable.

(5) switch current stabilization circuit (KW):

Function: the high voltage direct current output of control switch booster circuit obtains stable output current.

Constitute: form by current control module (U2), field effect transistor switch pipe (Q2), inductance (L2), diode (D2), electric capacity (C2) and resistance (R6, R7).

Principle: current control module (U2) is pressed the break-make of the FEEDBACK CONTROL switching tube (Q2) of output current, exports stable lamp current by the energy storage of inductance (L2) by diode.The break-make of switching tube is determined by current threshold.Current threshold is by the current feedback output control of level shift circuit (DYW).When electric current reached current threshold in the switching tube, switch current stabilization module was turn-offed switching tube, the inductance energy stored through diode to lamp tube power supply.When inductive current reduced to zero, switching tube is conducting again.When lamp current was big, current feedback reduced current threshold, otherwise current threshold is increased, and kept outputting current steadily.

The decapacitation of switch current stabilization circuit keeps outside the outputting current steadily, can also realize delayed startup, overtemperature protection and bright/dark controlled function (see figure 2) by current control module.

A, delayed startup:

Function: delayed startup circuit working after the device energized, treat restart switch current stabilization circuit work behind the filament pre-heating.

Constitute: form by switching tube (Q21), delay capacitor (C21), resistance (R24, R25).

Principle: after the device energized, filament transformer applies rectification by rectifier to capacitor C 21

Voltage (Vz).The electric capacity time-delay is after 0.5～1 second, and both end voltage makes switching tube Q21 conducting, will

Voltage (Vz) adds to switching power source chip (IC).Chip begins to accept current feedback, and control is opened

Close pipe Q2 break-make, output current is provided.

B, overtemperature protection:

Function: when switch current stabilization circuit temperature overheating, reduce output current automatically and make temperature reduce, the holding circuit temperature is normal.

Constitute: form by thermistor (Rt), resistance (R26, R27) and diode (D22).

Principle: reduce with circuit temperature rising thermistor (Rt) resistance, when temperature rises to setting (+125 ℃), the partial pressure value U27 of Rt and R27 is raise, make feedback voltage strengthen the current threshold that reduces switching tube by D22, R26.The reduction of output current reduces the total losses of device, thereby circuit temperature reduces.

C, bright/dark control:

Function: the selection by bright/dark control switch position, realize the control of bright attitude work of fluorescent tube or dark attitude work, and make the ratio of bright, dark attitude lamp current be about regulation numerical value.

Constitute: form by switching tube (Q22), pulse generator (MF) and resistance (R28, R29, R30).

Principle: bright when bright attitude is worked/dark control is input as high potential, makes the Q22 conducting on the one hand, and R29 resistance in parallel with R30 reduces, and current feedback reduces to make the lamp current threshold value to increase, and obtains big output current; On the other hand, 400 hertz of rectangular pulses of pulse generator (MF) output are narrowed down, the pressure turn-off time of Q2 diminishes, and the output current pulsewidth strengthens and obtains big average current, and fluorescent tube is in bright attitude work.Otherwise bright when dark attitude is worked/dark control is input as electronegative potential, and Q22 turn-offs and obtains little output current; Pulse generator (MF) output rectangular pulse broadens, and the output current pulsewidth reduces and obtains little average current, and fluorescent tube is in dark attitude work.

(6) bridge inverter main circuit (QN):

The bridge type inverse module (QL) that bridge inverter main circuit is a core by four switching tubes constitutes, export under the driving of 400 hz AC signals at transformer, the unidirectional current impulse transfer of switch current stabilization circuit output is become the positive and negative double current impulsing that replaces, make fluorescent tube be in 400 hertz of low-frequency ac operating states.

(7) state control circuit (ZK):

State control circuit is accepted on/off and bright/flush type switch control signal, and bright, the dark operating state of connection, disconnection and fluorescent tube of device is controlled.

When the on/off switch was in open position, the input power supply by transformer control electronic switch cut-out filament transformer disconnected 400 hertz of required drive signals of filament heating power supply, control chip DC power supply and bridge-type inverter thus.This moment, filament did not heat, and circuit quits work, and the high voltage direct current disappearance, and fluorescent tube extinguishes.Otherwise, when the on/off switch is in on-position, lamp tube starting.

When bright/flush type switch is in bright attitude position, provide high potential signal to current control module (U2), make fluorescent tube be in bright attitude work, otherwise be in dark attitude work by light/electric coupling.

(8) filament transformer (DB):

The former limit winding of filament transformer is connected to 115 volt of 400 hz AC power supply of aircraft by electronic switch.The low-voltage alternating-current heating power supply that provides to filament is provided the secondary winding, the DC power supply that provides to control circuit through rectifier and 400 hertz of drive signals that provide to bridge inverter main circuit.Filament transformer also comprises a double-metal thermal relay.When the filament transformer overtemperature, cut off the former limit of transformer winding input power supply.

2, take following measure for satisfying the aircarrier aircraft requirement:

(1) safety precautions:

Device in use can not influence the safety of aircraft, has considered safety precautions such as limit temperature, current limliting, isolated high-voltage, inhibition electromagnetic interference in scheme.

A, overtemperature prote:

When fluorescent tube filament short circuit or other reason caused that filament transformer is overheated to surpass 150 ℃, the double-metal thermal relay that is close to transformer cut off transformer input power supply automatically, and device quits work.When treating that the transformer temperature is lower than 100 ℃, connect transformer input power supply automatically, device is resumed work.

B, short-circuit protection:

When the device output short-circuit, because the switch current stabilization circuit plays the constant-current source effect, limiting short-circuit current is no more than rated operational current and plays a protective role.

C, overcurrent protection:

When the aircraft power supply input current surpassed setting, the input circuit fuse cut off the input power supply automatically, stopped device work.

D, personal security protection:

The on/off of operating personnel by the switch operating device, bright/dark control implemented State Control because state control circuit is isolated the back by transformer and light/electric coupling with the device inner high voltage, guaranteed operating personnel's safety.

E, inhibition radio frequency interference:

Radio-frequency filter has all been adopted in the bridge rectifier input and the output of switch current stabilization circuit of device, has suppressed the radio frequency conducted interference of device to external circuit and outer bound pair device.Device has adopted metal shell, has suppressed device the radio frequency width of cloth blackberry lily of external circuit and outer bound pair device is disturbed.Therefore both avoided also having avoided extraneous radio frequency interference to influence the device operate as normal because the radio frequency interference of device influences other electronic equipment operate as normal of aircraft.

The input power factor of f, raising device:

The boost switching circuit of device has adopted the power factor controlling chip, by the sinuous pulsation voltage (u after the full-wave rectification _l) current threshold of control switch pipe, the waveform that makes bridge rectifier output ripple electric current is a haversine, reduced harmonic component, and made input current and input voltage remain same-phase and improve input power factor, thereby reduced harmonic pollution aircraft power supply.

(2) improve the reliability measure:

Device should be under the aircarrier aircraft service condition reliable operation, in scheme, considered reliability measures such as anti-power-supply fluctuation, anti-transition and anti-high ambient temperature.

A, anti-power-supply fluctuation:

When aircraft input power-supply fluctuation, the boost switching circuit changes the current threshold of switching tube automatically according to power-supply fluctuation, keeps high voltage direct current output stable, the device operate as normal.

B, the spike of anti-the power supply:

When aircraft input power supply produced the peak voltage transition, the boost switching circuit made switching tube turn-off immediately, ends output.Treat to resume work after peak voltage disappears.

C, anti-high ambient temperature:

When the ambient temperature overshoot scope of device present position, the thermistor resistance reduces and reduces lamp current automatically in the switch current stabilization circuit, has guaranteed the device operate as normal.

D, reduction plant failure rate:

Crucial control circuit in the device adopts integrated circuit (IC) chip, has improved the reliability of device under the aircraft utilization condition.

E, shock-resistant, the vibration resistance ability of stiffening device:

Device adopts special warfares such as gluing in assembling, make device energy operate as normal under aircraft impact, vibration condition.

(3) satisfy bright/dark control and general requirement of fluorescent tube:

A, bright/dark control:

According to operating personnel's selection, the duty that device changes fluorescent tube output low frequency square wave current by the switch current stabilization circuit recently realize fluorescent tube bright/dark control.

B, satisfy multiple fluorescent tube instructions for use:

Device has adopted independently dual closed control circuit, and the fluorescent tube starting resistor is provided by the boost switching circuit, and lamp current is controlled by the switch current stabilization circuit.Therefore, device is applicable to start and control voltage and is no more than 650 volts of direct currents that power output is no more than 80 watts, about 250 milliamperes of bright attitude lamp current, dark about 50 milliamperes various model single tubes or the double-tube series fluorescent lamp of attitude lamp current.

(4) satisfy on the structural design that airliner is little, in light weight to device volume, the requirement of good heat dissipation:

On a, the Printed Circuit Board Design, entire circuit is divided into two circuit boards by its function, fits together so that component side is interspersed relatively.The heating panel of high power device plays the effect of structural support simultaneously again, makes total very compact and be easy to decompose, safeguard and assembling.

The shell of b, device is divided into two parts of base plate and last cover with the hard aluminium alloy board making of 0.8mm, handles through black anodizing, has both helped heat radiation and electromagnetic shielding, has realized the requirement of weight reduction again.

C, whole metal shell only need can be fixedly mounted on the cooling stand with the securing member of 4 band locking devices, and closely contact of the two maintenance, help the heat of device is discharged in the space towards periphery.The main feature of this device:

1, now same device mostly adopts single controller to realize fluorescent tube starting resistor and current controlling simultaneously, and both interact and have reduced the quality of device work in control.This device has adopted dual independent closed control circuit, respectively by boost switching circuit control fluorescent tube starting resistor, by switch current stabilization circuit control stabilization lamp current, realized the Optimal Control of starting resistor and lamp current, thereby improved the quality of device work.

2 compare with same device, and originally installing resits an exam considers the instructions for use of aircarrier aircraft, make device can be applicable to the illumination control of aircarrier aircraft fluorescent lamp.

The drawing explanation of Figure of description:

1, the drawing of " Fig. 1, voltage-limiting current-stabilizing device for fluorescent lamp circuit theory diagrams " explanation:

QZ---bridge rectifier; KS---boost switching circuit;

KW---switch current stabilization circuit; QN---bridge inverter main circuit;

YD---fluorescent tube; RD---disconnected device;

SL---frequency filter; U1---the control module of boosting;

U2---current control module; DYW---level shift circuit;

QL---bridge type inverse module; DB---filament transformer;

ZK---state control circuit.

2, the drawing of " Fig. 2, current control module schematic diagram " explanation:

IC---Switching Power Supply control chip; MF---pulse generator;

R _t---thermistor.

Claims (1)

1. Fluorescent lamp of aircraft pipe voltage-limiting current-stabilizing device one, independent

   Preorder: realize fluorescent tube starting resistor and current controlling are made the fluorescent tube operate as normal by the high-frequency pulsed width modulation technology.

   Feature: 1, the dual independent closed control circuit of employing is realized the Optimal Control to fluorescent tube starting resistor and operating current respectively;

   2, adopt low-frequency ac output significantly to reduce radio frequency interference;

   3, input circuit is realized power factor controlling, improve power factor and reduce harmonic pollution aircraft power supply;

   4, take the maltilevel security safeguard, guarantee aircraft utilization safety;

   5, take multiple reliability safeguard, reliable operation under the aircraft utilization condition;

   6, satisfy the fluorescent tube of aircraft bright/the secretly instructions for use of control and multiple model and combined fluorescent lamp tube;

   7, satisfy that aircarrier aircraft is little, in light weight to device volume, the instructions for use of good heat dissipation.Two, subordinate

   Right 1 is fit to the voltage-limiting current-stabilizing device (abbreviation device) of fluorescent tube work according to independent claims

   Comprise:

   (1) bridge rectifier is connected on the aircraft power supply by radio-frequency filter, the aircraft AC power is transformed into the pulsating voltage output of full-wave rectification;

   (2) the boost switching circuit is connected to bridge rectifier output, and the response voltage feedback increases to the pulsating voltage of full-wave rectification the high voltage direct current output of qualification;

   (3) the switch current stabilization circuit is connected to the output of boost switching circuit, and the response current FEEDBACK CONTROL is stablized the fluorescent tube electric current;

   (4) bridge inverter main circuit is connected to switch current stabilization circuit output, and the unidirectional current impulse transfer of switch current stabilization circuit output is become double current impulsing by fluorescent tube;

   (5) state control circuit is by the switching of electronic switch control filament transformer; And by bright, the dark control of switch current stabilization circuit realization fluorescent tube;

   (6) filament transformer is transformed into low-voltage alternating current power supply with the aircraft AC power, realizes the fluorescent tube filament heating.

   Right 2 is according to the requirement of right 1 boost switching circuit, and boost switching circuit response voltage feedback is modulated by amplitude, frequency to high-frequency impulse, the high voltage direct current output that obtains limiting.

   Right 3 is according to the requirement of right 1 boost switching circuit, and the boost switching circuit uses the power factor controlling chip, to input current waveform control, makes the boost switching circuit keep High Power Factor.

   Right 4 is according to the requirement of right 1 switch current stabilization circuit, and the switch current stabilization circuit uses the Switching Power Supply control chip, and the response current feedback is modulated by amplitude, frequency to high-frequency current pulse, obtains stable lamp current output.

   Right 5 is according to the requirement of right 1 switch current stabilization circuit, and the switch current stabilization circuit is implemented the low frequency switching current and lighted fluorescent tube, obtains high delivery efficiency.

   Right 6 is according to the requirement of right 1 switch current stabilization circuit, and the switch current stabilization circuit uses delay circuit, and fluorescent tube is lighted after filament heating time-delay.

   Right 7 is according to right 1 state control circuit requirement, and state control circuit passes through switch current stabilization circuit realization fluorescent tube, and bright/dark operating state is controlled.

   Right 8 is according to right 1 filament transformer requirement, and filament transformer provides low-voltage direct by rectification circuit for control circuit, and provides 400 hz AC driving voltages for bridge inverter main circuit.

   Right 9 guarantees that according to independent claims the device of aircraft utilization safety comprises:

   (1) cross flow fuse and be connected to the aircraft power supply input, input realizes overcurrent protection to aircraft power supply;

   (2) be close to the double-metal thermal relay of filament transformer, realize the filament short-circuit protection;

   (3) output realizes short-circuit protection to the switch current stabilization circuit to device;

   (4) state control circuit is realized the operator safety protection by electric quarantine measures;

   (5) take the radio frequency interference braking measure in the device, guarantee that other electronic equipment is not subjected to electromagnetic interference and influences work on the aircraft.

   Right 10 is according to right 9 overcurrent protection requirements, and when input current surpassed setting, fuse cut off the aircraft power supply input automatically, makes device termination work.

   Right 11 is according to right 9 filament short-circuit protection requirements; when filament short circuit or other reason make the filament transformer temperature surpass setting; double-metal thermal relay cuts off filament transformer input power supply automatically; middle filament breaking heating, control circuit and the required power supply of bridge-type inverter, device quits work.Through the certain hour sluggishness, when the filament transformer temperature is reduced to lower setting, the automatic energized of double-metal thermal relay, device is resumed work.

   Right 12 is according to right 9 short-circuit protection requirements, and when the fluorescent tube output short-circuit of device, it is constant that switch current stabilization circuit response current feedback is kept output current, realizes short-circuit protection.

   Right 13 is according to right 9 personal protection requirements, and state control circuit carries out the on/off and the bright/dark control of device after isolating by transformer, light/electric coupling and device inner high voltage circuit, guarantees operator safety.

   Right 14 suppresses requirement according to right 9 radio frequency interference, and bridge-type inverter provides low-frequency ac output to reduce radio frequency interference; The input and output circuit of device has adopted radio-frequency filter, and device adopted metal shell to suppress the device radio frequency interference, thereby has avoided the influence to other electronic equipment on the machine.

   Right 15 is according to independent claims, and the device of reliable operation comprises on the aircraft utilization condition:

   (1) the boost switching circuit adopts the power factor controlling chip, guarantees the device reliable operation under the aircraft power supply surging condition;

   (2) the boost switching circuit adopts the power factor controlling chip, guarantees the device reliable operation under aircraft power supply spike transient condition;

   (3) the switch current stabilization circuit adopts thermistor control lamp current, guarantees the device reliable operation under aircraft environment temperature rising condition;

   (4) device adopts integrated chip, reduces the plant failure rate;

   (5) device adopts the special gelatin adhering process, improves the shock-resistant and vibration resistance ability of device.

   Right 16 is according to right 15 anti-power-supply fluctuation requirements, when aircraft input power-supply fluctuation, the power factor controlling chip controls changes the amplitude and the frequency of high-frequency impulse in the boost switching circuit, and makes boost switching circuit output high voltage direct current keep stable, installs working properly.

   Right 17 is according to right 15 spike of anti-power supply requirements, and when aircraft input power supply produced the spike transition, power factor controlling chip instantaneous interruption was exported in the boost switching circuit, and holding device is working properly.

   Right 18 is according to right 15 anti-high ambient temperature requirements, and when device aircraft environment temperature of living in exceeded normal temperature, the thermistor resistance reduced and reduces lamp current automatically and assurance device is working properly in the switch current stabilization circuit.

   Right 19 reduces the requirement of plant failure rate according to right 15, and the control circuit to crucial in the device adopts up-to-date integrated chip to make device at aircraft utilization condition decline less trouble.

   Right 20 is according to right 15 shock-resistant, vibration resistance requirements, and easily loosening device adopts the special gelatin adhering process in the device, makes device can adapt to impact, the vibration condition assurance device operate as normal of aircraft.

   Right 21 is according to independent claims, satisfy the aircraft fluorescent lamp bright/secretly the device that uses of control and polytypic fluorescent lamp comprises:

   (1) by state control circuit fluorescent tube is realized bright, dark control;

   (2) by boost switching circuit control fluorescent tube starting resistor, stablize lamp current, realize the instructions for use of polytypic fluorescent tube by the switch current stabilization circuit.

   Right 22 is 21 bright according to right, secretly control requirement, and the duty that changes switch current stabilization circuit square wave pulsed current by state control circuit is recently realized bright, the dark control of fluorescent tube.

   Right 23 is according to right 21 polytypic fluorescent tube instructions for uses, device adopts independently dual control circuit, makes device be applicable to that starting resistor is no more than 650 volts of direct currents, power outputs and is no more than 80 watts, operating current and is roughly 250 milliamperes (bright attitudes) and the single tube of 50 milliamperes (dark attitudes) or the control of double tube fluorescent lamp.

   Right 24 is according to independent claims, satisfies that aircarrier aircraft is little, in light weight to device volume, the instructions for use of good heat dissipation:

   (1) appropriately divides and design printed circuit, make compact conformation.

   (2) adopt the aluminum metal shell.

   (3) with anti-loose fastener shell is closely contacted with heating panel.

   Right 25 is according to right 24, and Printed Circuit Board Design is divided into two up and down, interts relatively with component side and assembles, and the heating panel of high power device plays the effect of structural support simultaneously.

   Right 26 is according to right 24, and the metal shell of device is made of 0.8mm aluminum plate material, is divided into base plate and last cover two partly, handles through black anodizing, make in light weight, good heat dissipation.

   Right 27 is according to right 24, and whole metal shell is installed on the cooling stand with 4 band locking device securing members, and closely contact of the two maintenance, to keep good radiating condition.