CN219042024U

CN219042024U - Surge-resistant electronic ballast for ultraviolet germicidal lamp

Info

Publication number: CN219042024U
Application number: CN202223120388.8U
Authority: CN
Inventors: 任玉林
Original assignee: Sichuan Aojie Disinfection Equipment Co ltd
Current assignee: Sichuan Aojie Disinfection Equipment Co ltd
Priority date: 2022-11-22
Filing date: 2022-11-22
Publication date: 2023-05-16
Anticipated expiration: 2032-11-22

Abstract

The utility model provides an anti-surge electronic ballast for an ultraviolet germicidal lamp, which comprises a rectifying and filtering circuit, a high-frequency oscillation switch filtering circuit, a first output load resonant circuit and a second output load resonant circuit, wherein an inductor L1 is connected in series between the input end of the rectifying and filtering circuit and a power supply, and the inductance of the inductor L1 is 1.8-2.0mH. The circuit of the electronic ballast can reduce surge current and peak value of input current pulse by utilizing the principle that two ends of the inductor cannot be suddenly changed, thereby reducing harmonic content and being very suitable for ultraviolet germicidal lamps with the power of 30-36W.

Description

Surge-resistant electronic ballast for ultraviolet germicidal lamp

Technical Field

The utility model relates to the technical field of electronic ballasts, in particular to an anti-surge electronic ballast for an ultraviolet germicidal lamp.

Background

The ultraviolet sterilizing lamp is a lamp which performs sterilization and disinfection by utilizing the sterilization effect of ultraviolet rays, and the ultraviolet sterilizing lamp radiates ultraviolet rays with the wavelength of 253.7nm outwards. The ultraviolet ray with the highest sterilization capability can be used for sterilizing water, air, clothes and the like. Most uv germicidal lamps use an electronic ballast.

The surge current means a peak current flowing into the power supply device at the moment when the electrical device is turned on. The peak current is much greater than the steady state input current due to the rapid charging of the input filter capacitor, etc. In the input filtering of the ultraviolet germicidal lamp, large energy storage capacitors are adopted for filtering and voltage stabilization in design. At the moment of powering up the device, the capacitor voltage cannot be suddenly changed, so that a large charging current is generated, i.e. the capacitor is regarded as a short circuit in a short time. According to the first order circuit zero state response model, the initial current value corresponds to the current value that shorts the filter capacitor. I.e. the input surge current, the magnitude of which depends on the magnitude of the input voltage and the total circuit of inductance and capacitance in the whole loop.

The duration of the surge current is short, but if the surge current is not processed, the service life of the capacitor and other components in the device is shortened, and other devices in the power network are also affected, so that the instantaneous voltage of other devices in the same power network is reduced, and interference is formed. In the use process of the electronic ballast, the electronic ballast is inevitably influenced by surge current, and how to improve the anti-surge capacity of the electronic ballast is a key for preventing the electronic ballast from being damaged.

Disclosure of Invention

The utility model provides an anti-surge electronic ballast for an ultraviolet germicidal lamp, which aims at the technical problem that the electronic ballast is damaged due to the influence of surge current in the use process of the electronic ballast.

The technical scheme of the utility model is that the anti-surge electronic ballast for the ultraviolet germicidal lamp comprises a rectifying and filtering circuit, a high-frequency oscillation switch filtering circuit, a first output load resonant circuit and a second output load resonant circuit, wherein an inductor L1 is connected in series between the input end of the rectifying and filtering circuit and a power supply, the inductance of the inductor L1 is 1.8-2.0mH, the rectifying and filtering circuit comprises rectifying diodes D1, D2, D3 and D4 and filtering capacitors C1 and C2, a diode D5 is connected between the negative electrode of the capacitor C1 and the positive electrode of the capacitor C2, the positive electrode of the diode D5 is connected with the capacitor C1, a diode D7 is connected between the positive electrode of the capacitor C1 and the positive electrode of the capacitor C2, a diode D6 is connected between the positive electrode of the diode D5 and the positive electrodes of the diodes D2 and D4, and the positive electrode of the diode D6 is connected with the diodes D2 and D4.

Further, the inductance of the inductor L1 was 1.9mH.

Further, the high-frequency oscillation switch filter circuit comprises resistors R1, R2, R3, R4, R5, R6, capacitors C3, C4, a transformer, triodes V1, V2, diodes D8, D9, D10 and a diac DB3.

Further, the transformer is formed by winding three coils on one annular magnetic core, and the inductance of the three coils of the transformer is 19 mu H, 8 mu H and 19 mu H respectively.

Further, the first output load resonant circuit includes an inductance L3 and capacitances C5, C6, C7.

Further, the second output load resonant circuit includes an inductance L3, capacitances C5, C6, C8, and a negative temperature coefficient thermistor, and the capacitance C8 and the negative temperature coefficient thermistor are connected in parallel.

Further, the electronic ballast also has a silicon controlled rectifier.

The utility model has the beneficial effects that the inductance coil L1 in the electronic ballast plays an anti-surge role, namely the anti-surge circuit comprises an inductance L1 connected in series between the input end of the rectifying and filtering circuit and a power supply, the inductance L1 is connected in series at the input power supply end, the inductance of the inductance L1 is designed to be 1.8-2.0mH, the surge current can be reduced by utilizing the principle that the two ends of the inductance cannot be suddenly changed, the peak value of the input current pulse can be reduced, and therefore, the harmonic content is reduced, and the utility model is very suitable for 30-36W ultraviolet germicidal lamps.

The electronic ballast is connected with the diodes D5, D6 and D7 into the rectifying and filtering circuit, can effectively inhibit direct current surge, has the function of stroboscopic prevention, and can eliminate the flickering phenomenon of the ultraviolet germicidal lamp.

Drawings

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

Detailed Description

The utility model is further described below with reference to examples.

As shown in fig. 1, the utility model relates to an anti-surge electronic ballast for an ultraviolet germicidal lamp, the circuit of the electronic ballast comprises a rectifying and filtering circuit, a high-frequency oscillation switch filtering circuit, a first output load resonant circuit and a second output load resonant circuit, an inductor L1 is connected in series between the input end of the rectifying and filtering circuit and a power supply, the inductance of the inductor L1 is 1.8-2.0mH, the inductance of the inductor L1 is 1.9mH as an optimal scheme, the rectifying and filtering circuit comprises rectifying diodes D1, D2, D3 and D4 and filtering capacitors C1 and C2, a diode D5 is connected between the negative electrode of the capacitor C1 and the positive electrode of the capacitor C2, the positive electrode of the diode D5 is connected with the capacitor C1, the positive electrode of the diode D7 is connected with the capacitor C2, a diode D6 is connected between the positive electrode of the diode D5 and the positive electrodes of the diodes D1 and D2, and the positive electrodes of the diodes D6 are connected with the diodes D1 and D2. The electronic ballast is connected with the diodes D5, D6 and D7 into the rectifying and filtering circuit, can effectively inhibit direct current surge, has the function of stroboscopic prevention, and can eliminate the flickering phenomenon of the ultraviolet germicidal lamp.

The high-frequency oscillation switch filter circuit comprises resistors R1, R2, R3, R4, R5 and R6, capacitors C3 and C4, a transformer, triodes V1 and V2, diodes D8, D9 and D10 and a diac DB3, wherein the transformer is formed by winding three coils (L2-1, L2-2 and L2-3) on a ring-shaped magnetic core, and the inductance of the three coils (L2-1, L2-2 and L2-3) of the transformer is 19 mu H, 8 mu H and 19 mu H respectively. The first output load resonant circuit comprises an inductor L3 and capacitors C5, C6 and C7, and the second output load resonant circuit comprises an inductor L3, capacitors C5, C6 and C8 and a negative temperature coefficient thermistor (NTC thermistor), wherein the capacitor C8 and the negative temperature coefficient thermistor are connected in parallel. The inductance of the inductor L3 was 1.7mH. At cold start, the NTC thermistor presents a high impedance, so that the inrush current at this time is limited. When the temperature of the NTC thermistor is increased due to the thermal effect of the current, the NTC resistance value is drastically reduced, and the current limiting effect on the system is smaller. However, since the impedance of the NTC thermistor in a thermal state is not 0, power loss is generated, thereby affecting the operation efficiency of the system. In addition, when the NTC thermistor is restarted in a hot state, the NTC thermistor has no limiting effect on surge current. Therefore, the present utility model short-circuits the NTC thermistor through an SCR (silicon controlled rectifier) or the like provided after the system is started. The efficiency is improved, the working time of the NTC resistor is reduced, the service life of the NTC resistor is prolonged, and the NTC resistor can be applicable to the frequent starting and stopping of the ultraviolet sterilizing lamp. In addition, the electronic ballast is designed to be output in a double-way mode, the first output load resonant circuit and the second output load resonant circuit are respectively connected and output, and the design shares the rectifying and filtering circuit and the high-frequency oscillation switch filtering circuit, so that the production cost can be further reduced.

When the power is turned on, the alternating current is rectified and filtered by the rectifying diodes D1, D2, D3 and D4 and the filter capacitors C1 and C2 of the rectifying and filtering circuit to obtain direct current voltage. The dc voltage charges the capacitor C4 through the resistor R1, and when the voltage on C4 exceeds the trigger voltage of the diac DB3, the diac DB3 is turned on, and a forward pulse current is applied to the base of the transistor V2 to turn it on. At this time, the voltage is charged through a charging loop composed of a capacitor C5, a filament of the ultraviolet germicidal lamp, an inductor L3, transformer windings L2-2, V2 and a resistor R6. The capacitor C7 and the inductor L3 form a series resonant circuit, when V2 is conducted, V2 is still conducted due to the polarities of windings L2-1, L2-2 and L2-3 in the transformer, and V1 is reversely cut off. When the charging process is finished, polarities of induced electromotive forces of L2-1 and L2-3 are suddenly reversed, at the moment, the circuit is turned over, V1 becomes on, and V2 becomes off. The charge on capacitor C4 in the series resonant circuit is then discharged through V1 and R5, causing the series resonant circuit to oscillate and produce a square wave (i.e., switching wave) voltage. The square wave is fed to a series resonant circuit of the inductance L3 and the capacitance C7 to form a high-frequency oscillating voltage approximating a sine wave. The filaments of the ultraviolet germicidal lamp connected in series in the charge-discharge loop are preheated at the same time. The high-frequency voltage on C7 is directly applied to two ends of the lamp tube to light the lamp tube, and after the lamp tube is lighted, the voltage is reduced to the working voltage due to the current limiting effect of the inductor L3. The current mainly passes through the lamp tube, but the C7 branch still has certain shunt, and has auxiliary heating effect on the filament. Similarly, the second output load resonant circuit operates in the same manner.

The inductance coil L1 in the electronic ballast plays an anti-surge role, namely the anti-surge circuit comprises an inductance L1 connected in series between the input end of the rectifying and filtering circuit and a power supply, the inductance L1 is connected in series at the input power supply end, the inductance of the inductance L1 is designed to be 1.8-2.0mH, surge current can be reduced by utilizing the principle that two ends of the inductance cannot be suddenly changed, the peak value of input current pulse is reduced, and therefore the harmonic content is reduced, and the electronic ballast is very suitable for an ultraviolet germicidal lamp with 30-36W.

However, the foregoing description is only illustrative of the present utility model and is not intended to limit the scope of the utility model, so that the substitution of equivalent elements or equivalent variations and modifications within the scope of the utility model are intended to fall within the scope of the claims.

Claims

1. The anti-surge electronic ballast for the ultraviolet germicidal lamp is characterized in that a circuit of the electronic ballast comprises a rectifying and filtering circuit, a high-frequency oscillation switch filtering circuit, a first output load resonant circuit and a second output load resonant circuit, an inductor L1 is connected in series between an input end of the rectifying and filtering circuit and a power supply, the inductance of the inductor L1 is 1.8-2.0mH, the rectifying and filtering circuit comprises rectifying diodes D1, D2, D3 and D4 and filtering capacitors C1 and C2, a diode D5 is connected between a negative electrode of the capacitor C1 and an anode of the capacitor C2, an anode of the diode D5 is connected with the capacitor C1, a diode D7 is connected between an anode of the capacitor C1 and an anode of the capacitor C2, a diode D6 is connected between an anode of the diode D5 and anodes of the diodes D2 and D4, and an anode of the diode D6 is connected with the diodes D2 and D4.

2. An anti-surge electronic ballast for an ultraviolet germicidal lamp as recited in claim 1 wherein the inductance L1 has an inductance of 1.9mH.

3. The electronic ballast for an ultraviolet germicidal lamp according to claim 1, wherein the high frequency oscillating switch filter circuit comprises resistors R1, R2, R3, R4, R5, R6, capacitors C3, C4, a transformer, transistors V1, V2, diodes D8, D9, D10 and diac DB3.

4. An anti-surge electronic ballast for ultraviolet germicidal lamp as in claim 3 wherein the transformer is comprised of three coils wound around a toroidal core, the three coils of the transformer having inductance of 19 μh, 8 μh, 19 μh, respectively.

5. An anti-surge electronic ballast for an ultraviolet germicidal lamp as in claim 1 wherein the first output load resonant circuit comprises an inductance L3 and capacitances C5, C6, C7.

6. The electronic ballast for an ultraviolet germicidal lamp as set forth in claim 1 wherein the second output load resonant circuit comprises an inductance L3, a capacitance C5, C6, C8 and a negative temperature coefficient thermistor, the capacitance C8 and the negative temperature coefficient thermistor being connected in parallel.

7. An anti-surge electronic ballast for an ultraviolet germicidal lamp as recited in claim 1 wherein the electronic ballast comprises a silicon controlled rectifier.