CN2157615Y - Demagnetisation protection arrangement for electronic transformer - Google Patents

Abstract

The utility model provides a demagnetisation protection device for an electronic transformer, which comprises a bridge rectifier circuit, a start-up circuit, a switch oscillation circuit, a transformer feedback coupling circuit, an output circuit and a protection circuit. The electronic transformer is used for quartz lamps and neon lamps. The utility model is characterized in that the coupling signal of the switch oscillation circuit is interrupted by the demagnetisation principle. A switch tube stops oscillating, which can protect the electronic transformer. The utility model simultaneously and ideally solves a plurality of defects, such as overvoltage, overload, open circuit, short circuit, overtemperature, etc. The utility model also provides protection when a neon lamp frequently scans. The service life of the electronic transformer is effectively prolonged.

Description

Demagnetisation protection arrangement for electronic transformer

The utility model relates to electronic transformer, particularly a kind of degaussing protective device of electronic transformer.

Existing electronic transformer has economize on electricity, saves steel, volume is little, in light weight and advantage such as easy for installation, just progressively replaces traditional appendiron core transformer.Electronic transformer is to be exclusively used in quartz lamp, neon light etc., and it can directly be transformed to the high frequency voltage supply load that is higher than 20KHz to the line voltage of 50Hz.Therefore it is just progressively accepted by users.But, this product in use, often because voltage ripple of power network, reasons such as user's improper use or load variations, and cause abnormal conditions such as overvoltage, overload, short circuit, open circuit and overtemperature cause product badly damaged or burn.Because the spoilage height of this product, poor reliability is its main cause of promoting the use of of overslaugh.How to improve the reliability of electronic transformer, a great problem that the domestic and international in recent years just relevant personnel seek to solve.

The purpose of this utility model provides a kind of degaussing principle of utilizing and realizes protection to electronic transformer, thus the degaussing protective device that electronic transformer can not damaged because of situations such as overvoltage, overload, open circuit, short circuit and overtemperatures.

Technical solution of the present utility model is: electronic transformer degaussing protective device comprises that bridge rectifier, start-up circuit, switch oscillating circuit, transformer feedback coupling circuit, output circuit, protective circuit form jointly.Its solution is: protective circuit is made of the coil n7 of thyristor T3, degaussing coil n4, diode D7-D9, resistance R 6-R11, capacitor C 5 and high frequency transformer B2; the positive pole of the terminating diode D7 of coil n4 wherein; the common port of the other end connection circuit of n4; resistance R 6 one termination power positive poles; the anode A of another termination thyristor T3 and the negative pole of diode D7; resistance R 7 is attempted by between the A and K end of thyristor T3, the common port of the other end connection circuit of R7.The positive pole of diode D8 connects the emitter of switch transistor T 2, negative pole meets the control end G of thyristor T3 through resistance R 8, be connected on the capacitor C 5 and resistance R 9 in addition of T3 control end simultaneously, the common port of the other end connection circuit after capacitor C 5 and resistance R 9 are in parallel, be connected on the coil n7 that also has resistance R 11 serial connection diode D9, transformer B2 of T3 control end, the other end connection circuit common port of coil n7.Described output circuit is made up of coil n5, n6 and capacitor C 3, the C4 of high frequency transformer B2.Wherein be connected across the positive and negative two ends of power supply after capacitor C 3 and the C4 series connection, the end of coil n5 is connected with the end of the coil n1 of coupling magnet ring B1, the other end of coil n5 is connected on the tie point of capacitor C 3 and C4, electronic transformer for for neon light also is provided with a pair of discharge copper pin on two output a, the b.

Fault detection signal of the present utility model both can be obtained from the emitter resistance R3 of switch transistor T 2, obtained on the magnetic test coil n7 of some circles of coiling on the magnetic core of high frequency transformer B2 that also can be in output circuit.Detection signal can also be obtained from resistance R 10, at this moment, and the right-hand member of the positive pole of diode D8 from the emitter-base bandgap grading reconfiguration of switch transistor T 2 to resistance R 10, and another termination protective circuit common port of R10.

The utility model also is: degaussing coil n4 is wound on the couples back magnet ring B1, and wherein the high-frequency induction voltage of coil n4 is delivered on the resistance R 7 by halfwave rectifier or full-wave rectification or bridge rectifier.In addition, the main element of control short-circuited coil n4 short circuit can also adopt contact switch element such as miniature relay except adopting contactless element thyristor T3 or transistor.

The utility model has the advantages that: except advantage, following advantage is arranged especially with general electronic transformer:

(1) adopt such scheme to make the utility model solve several error protections such as overvoltage, overload, open circuit, short circuit, overtemperature simultaneously in very good ground.Have characteristics such as circuit structure is simple, dependable performance.

(2) when circuit is protected, switch oscillating circuit failure of oscillation is in the timeout state, and the electrical network input power drops to not enough 1W, and has memory function.Have only power cutoff, energized again after fixing a breakdown, entire circuit is just recovered operate as normal again.

(3) utilize the degaussing principle to make the switch oscillating circuit lose oscillating condition and break-off has caught the essence of electronic transformer to protect from principle, therefore; elements all during protection do not generate heat; consumed power not even be in guard mode for a long time, can not damaged any element yet yet.

Below in conjunction with accompanying drawing the utility model is illustrated,

Fig. 1 is a circuit structure diagram of the present utility model.

As shown in Figure 1; this electronic transformer degaussing protective device; by bridge rectifier (diode D1-D4, capacitor C 1), start-up circuit (resistance R 1, capacitor C 2, diode D6), switch oscillating circuit (switch transistor T 1, T2, resistance R 2-R5); transformer feedback coupling circuit (coupling magnet ring B1 and coil n1-n3); output circuit (transformer B2, capacitor C 3, C4), protective circuit (coil n4, diode D7-D9, resistance R 6-R11, thyristor T3, the n7 of coupling magnet ring B1) is common to be constituted.

Its operation principle is: line voltage obtains about 300 volts of direct voltages through after the bridge rectifier filtering, when capacitor C 2 when resistance R 1 charges to the puncture voltage of diode D6, diode D6 conducting immediately, trigger switch pipe T2 conducting.Sense of current is from coil n5 → coil n1 → switch transistor T 2 → resistance R 3 → power cathode of positive source → capacitor C 3 → high frequency transformer B2 at this moment.Capacitor C 3 chargings this moment, C4 discharge, the ending of the same name of coil n2, n3 has guaranteed that switch transistor T 2 saturated T1 end in the accompanying drawing.Owing to the sign modification of flux change rate causes the polarity inversion of the induced voltage of magnetic ring coil n2, n3, cause switch transistor T 2 saturated by T1.This moment sense of current from capacitor C 3 upper ends → coil n5 → capacitor C 3 lower ends of switch transistor T 1 → resistance R 2 → coil n1 → high frequency transformer B2, make the C3 discharge, energy is sent back to power supply, C4 charging simultaneously.Switch transistor T 1, T2 so constantly replace saturated with end, high frequency voltage of output boosts and lights neon light or step-down removes to light quartz lamp on the coil n6 of high frequency transformer B2.

The operation principle of protective circuit is: when any faults such as circuit generation overvoltage, overload, short circuit, open circuit, overtemperature; from coil n7 or measure fault-signal (they be or relation) from resistance R 3 and deliver on the control end G of thyristor T3; make the T3 conducting coil n4 short circuit; produce a bigger short circuit ampere-turn; make magnet ring B1 enter demagnetizing state, the flux change rate is minimum, and the feedback voltage on coil n2, the n3 disappears substantially; make switch transistor T 1, T2 failure of oscillation, circuit is subjected to reliably protecting.

To neon sign electron transformer, on two output a, the b of the coil n6 of the transformer B2 of output circuit, a pair of discharge copper pin is set.When high voltage package output a, b opened a way, the high voltage of 15KV just produced electric arc by the copper needle-discharging, and powerful electric arc is output a, b short circuit, and circuit is failure of oscillation immediately.

During protection, resistance R 6 obtains from DC power supply and keeps electric current, and the reliable conducting of protection thyristor T3 keeps n4 by short circuit.Owing to utilized the degaussing principle to come the coupled signal of interrupt switch oscillating circuit, make the switching tube failure of oscillations, caught the work essence of electronic transformer to protect from principle.Therefore, all elements neither generate heat during protection, and consumed power not even be in guard mode for a long time, can not damaged any element yet, thereby guarantee the useful life of electronic transformer yet.

Claims (4)

1; a kind of electronic transformer degaussing protective device; comprise bridge rectifier; start-up circuit; the switch oscillating circuit; the transformer feedback coupling circuit; output circuit; protective circuit constitutes; it is characterized in that: described protective circuit is by thyristor T3; degaussing coil n4; diode D7-D9; the coil n7 of resistance R 6-R11 and high frequency transformer B2 constitutes; the positive pole of the terminating diode D7 of coil n4 wherein; the common port of the other end connection circuit of n4; resistance R 6 one termination power positive poles; the anode A of another termination thyristor T3 and the negative pole of diode D7; resistance R 7 is attempted by between the A and K end of thyristor T3; the common port of the other end connection circuit of R7; the positive pole of diode D8 connects the emitter of switch transistor T 2; negative pole connects the control G end of thyristor T3 through resistance R 8; on the G end that is connected across thyristor T3 after capacitor C 5 and resistance R 9 are in parallel and the circuit common; resistance R 11 serial connection diode D9 connect the end of the coil n7 of transformer B2; the common port of the other end connection circuit of n7; for step-up transformer, at the two output a of the coil n6 of high frequency transformer B2; also be provided with a pair of discharge copper pin on the b.

2, electronic transformer degaussing protective device according to claim 1; it is characterized in that: fault detection signal both can be obtained from the emitter resistance R3 of switch transistor T 2; the coil n7 of some circles of coiling detects on the magnetic core of high frequency transformer B2 that also can be in output circuit; its detection signal can also be obtained from resistance R 10; with the positive pole of diode B8 right-hand member, the other end protective circuit common port of R10 from the emitter-base bandgap grading reconfiguration of switch transistor T 2 to resistance R 10.

3, electronic transformer degaussing protective device according to claim 1; it is characterized in that: degaussing coil n4 is wound on the couples back magnet ring B1, and wherein the high-frequency induction voltage of coil n4 is delivered on the resistance R 7 by halfwave rectifier or full-wave rectification or bridge rectifier.

4, according to claim 1 or 3 described electronic transformer degaussing protective devices; it is characterized in that: the main element of control short-circuited coil n4 short circuit is except adopting contactless element thyristor T3 or transistor; can also adopt the contact switch element, as miniature relay.