CN2269046Y

CN2269046Y - Electronic ballast for sodium lamp

Info

Publication number: CN2269046Y
Application number: CN 96235418
Authority: CN
Inventors: 吴福仪
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-07-28
Filing date: 1996-07-28
Publication date: 1997-11-26
Anticipated expiration: 2006-07-28

Abstract

The utility model relates to an electronic ballast for a sodium lamp, belonging to the technical field of electronic technology. The utility model is composed of a casing, a binding post, a filtering rectification circuit (1), an LC self-excited oscillation circuit (2) and an open circuit protective circuit (3). When moment switching over of a power supply is realized, moment switching off phenomenon of a lighting fitting can not be generated. Once power failure happens, power can be supplied in a short time. The hot start of the lighting fitting can be realized in a short time; when a lighting fitting is not connected with the utility model, a circuit can not be damaged because of over voltage and over current. Owing to the adoption of the design, start or hot start of a sodium lamp can be easily started, and the utility model has the advantages of low cost, small volume and power saving. The power factor of the utility model approximately equals 1.

Description

A kind of electronic ballast of sodium lamp

The utility model belongs to electronic technology field, relates in particular to a kind of electronic ballast of sodium lamp.

There are traditional inductance type ballasts such as PHILIPS BAS-55 type present existing sodium lamp ballast, and the high pressure that the principle that it utilizes inductive current not suddenly change produces in short-term is added in light fixture the two poles of the earth, makes gas discharge puncture in the lamp, and conducting is luminous then.The deficiency of the maximum of this class ballast is: the warm start poor performance, when mains lighting supply was switched, it was luminous to make usefulness sodium vapor lamp after a while not restart immediately, only remained sodium vapor lamp after cooling after a while, could continue to be activated, and had influenced lighting quality.Simultaneously this class ballast cost height, volume is big, energy consumption is big.

Task of the present utility model is exactly to design the good sodium lamp ballast of a kind of warm start performance with all electronic component.Be particularly suitable for the startup and the warm start of low-pressure sodium lamp.

This sodium lamp ballast is made up of shell, binding post and filter rectifier (1), LC self-maintained circuit (2) and open loop protection circuit (3).When connecing the load light fixture; mains lighting supply is through filter rectifier rectification output dc voltage; through open loop protection circuit L, C self-maintained circuit are started working; circuit is drawn among inductance that part energy is stored in oscillating circuit, the electric capacity from power supply; make parameters such as electric current in the circuit, voltage increase like this along with increasing progressively of cycle of oscillation; when output voltage V 0 increases to when making in the light fixture gas electrical breakdown; the light fixture conducting; open loop protection circuit has guaranteed that bidirectional triode thyristor SCR continues conducting simultaneously, and circuit oscillation begins to keep a kind of poised state.When power supply moment switched, because the C2 discharge, light fixture can not produce moment and extinguish phenomenon.The back short time sends a telegram here again in case have a power failure, and L, C oscillating circuit are started working and energy accumulation, and through after some cycles of oscillation, i.e. in very short time, circuit produces high output voltage, with the light fixture warm start.

When not connecing the light fixture load, open loop protection circuit makes L, C oscillating circuit cut off the power supply and quit work, thereby make circuit can not be damaged because of overvoltage, overcurrent; In case connect the light fixture load, L, the work of C oscillating circuit also produce high output voltage, immediately light fixture are started, and open loop protection circuit has guaranteed the entire circuit operate as normal simultaneously.

After adopting this design, can not only start easily or the warm start sodium vapor lamp, improve lighting quality, and owing to adopt all electronic component, this sodium lamp ballast cost is low, volume is little, also approximates 1 because of its power factor (PF), this rectifier energy consumption is little, has saved electric energy greatly.

Fig. 1 is the circuit diagram of sodium lamp ballast.

Fig. 2 is the schematic diagram of sodium lamp ballast.

Give explanation below in conjunction with example.

The sodium lamp ballast is made up of binding post 1, shell 2 and circuit 3 as shown in Figure 2.

Circuit is to connect so as shown in Figure 1:

Exchange input through protective tube, and be connected with a piezo-resistance,, form filter rectifier (1) by diode D1--D4 by the towering type filter circuit that L1, C1, L2, L3 form.

The positive pole of electrochemical capacitor C2 connects the positive pole of rectifier bridge, and joins with the c utmost point of switching tube Q1, and the e utmost point of Q1 connects the c utmost point of Q2 through R3, and the e utmost point of Q2 connects the negative pole of C2 through R4; Diode D5 is in parallel with capacitor C 4, and the negative pole of D5 connects the positive pole of C2, and the positive pole of D5 connects the c utmost point of Q2 and the negative pole of diode D6, and the positive pole of D6 connects the negative pole of C2; Connect with inductance L 5, capacitor C 7, C8 in the former limit 12 of transformer T1, C8 connects the positive pole of C2, the c utmost point of the 2 termination Q2 on the former limit 12 of T1; T1 two secondary 1 ' 2 ' and 1 " 2 " connect b ' utmost point of Q2 and Q1 by end of the same name and non-same polarity respectively through resistance R 6 and R5 respectively, two secondary 1 ' 2 ' and the other end of 1 " 2 " connect the negative pole of C2 and the c utmost point of Q2 respectively; Diode D7 and D8 connect e, the b utmost point of Q1 and Q2 respectively; The positive pole of trigger tube DB2 and diode D9, resistance R 2, capacitor C 6 are joined, the b utmost point of its another termination Q2; The negative pole of D9 connects the c utmost point of Q2; The other end of R2, C6 connects the positive pole of C2 and the negative pole of rectifier bridge respectively, constitutes L, C self-maintained circuit (2).

Connect with load in the former limit of feedback transformer T2, then with the C7 parallel connection; Bidirectional triode thyristor SCR is connected between the negative pole of the negative pole of rectifier bridge and C2, and its grid meets trigger tube DB1; The other end of DB1 joins with positive pole and the resistance R 1 of electrochemical capacitor C3, the positive pole of another termination rectifier bridge of R1, and the negative pole of C3 connects the negative pole of rectifier bridge; The secondary of T2 is through diode D10, D11 full-wave rectification, and rectification output is with electrochemical capacitor C10 and connect, and the positive pole of C10 connects the grid of SCR through resistance R 7, and capacitor C 9 is with R7 and connect, and constitutes open loop protection circuit (3).

The circuit working process is as follows:

Exchange V _IImport the filtering of towering type filter circuit through binding post, again through the rectifier bridge rectification, the direct voltage V of output pulsation _CA

When being connected to light fixture load, V _CACharge to C3 through R1, when the voltage of C3 was charged to 30V, trigger tube DB1 conducting triggered bidirectional triode thyristor SCR conducting, and C2 is full of electricity at once, C2 filtering output V _CBBe direct voltage stably.Simultaneously, DB2 triggers the Q2 conducting immediately, and startup L, C oscillating circuit are started working; T1 makes and Q1, Q2 alternate conduction constitutes self-maintained circuit with original papers such as L5, C7, C8, C4 that the current cycle ground in the circuit increases, reduces, increases, reduces, and increases, reduces in the other direction; Every circuit is drawn part energy from power supply through a cycle of oscillation, and is stored among the inductance, electric capacity of oscillating circuit, makes parameters such as electric current in the circuit, voltage increase along with increasing progressively of cycle of oscillation like this; Through after several cycles of oscillation, in the promptly extremely short time, output voltage V 0 increases to and makes that gas discharge punctures in the light fixture, the light fixture conducting, and this moment, the output of T2 secondary provided the grid triggering signal through R7 to SCR, as V subsequently _AB＞0 o'clock, this triggering signal guaranteed SCR reverse-conducting again, and SCR can be because of V _AB＞0 automatically shuts down, thereby makes SCR keep conducting state, entire circuit operate as normal.When power supply moment switches, because the C2 discharge, kept the operate as normal of L, C self-maintained circuit, light fixture can not produce moment and extinguish phenomenon.The back short time sends a telegram here again in case have a power failure, and L, C oscillating circuit are started working and energy accumulation, and through after some cycles of oscillation, i.e. in very short time, circuit produces high output voltage, with the light fixture warm start.

When not connecing the light fixture load, i.e. open-circuit condition, T2 secondary no-output, circuit oscillation is through V _CATime of half period after, at this moment C2 plays the shutoff effect, C2 makes the voltage V of SCR inside _AB＞0, and this moment SCR the grid Triggerless, SCR automatically shuts down because of negative pressure, L, C oscillating circuit quit work because of outage; By the time during the following one-period of DB1 triggering signal, DB1 triggers the SCR conducting, but very fast SCR is because V _AB＞0 and automatically shut down, make L, C self-maintained circuit to work like this, thereby guarantee that circuit can not cause overvoltage, overcurrent.In case connect the light fixture load, the very fast breakdown conducting of light fixture, the output of T2 make works as V _AB＞0 o'clock, SCR is reverse-conducting again, worked as V _AB＜0, SCR is forward conduction again, has guaranteed the circuit operate as normal, and light fixture is normally luminous.

Because the triggering signal cycle of DB1 is greater than V _CACycle, circuit can not be damaged because of open circuit causes overvoltage, overcurrent; Because V _CACycle greater than the self-oscillatory cycle of L, C, so this rectifier is easy to start or the warm start light fixture.In addition, because output voltage is the positive negative pulse stuffing of high frequency, so this ballast is than easier startup of inductance type ballast or warm start light fixture.

By adjusting subelement parameter in the circuit, when making the frequency of output voltage V 0=30-70KHz, circuit working state is the most stable.

Claims

1, a kind of electronic ballast of sodium lamp comprises shell, wiring osmanthus, filter rectifier (1), LC self-maintained circuit (2) and open loop protection circuit (3), it is characterized in that:

1., L, C self-maintained circuit (2) connect like this: the positive pole of electrochemical capacitor C2 connects the positive pole of rectifier bridge, and joins with the c utmost point of switching tube Q1, and the e utmost point of Q1 connects the c utmost point of Q2 through R3, and the e utmost point of Q2 connects the negative pole of C2 through R4; Diode D5 is in parallel with capacitor C 4, and the negative pole of D5 connects the positive pole of C2, and the positive pole of D5 connects the c utmost point of Q2 and the negative pole of diode D6, and the positive pole of D6 connects the negative pole of C2; Connect with inductance L 5, capacitor C 7, C8 in the former limit 12 of transformer T1, C8 connects the positive pole of C2, the c utmost point of the 2 termination Q2 on the former limit 12 of T1; Two secondary 1 ' 2 of T1 ' and 1 " 2 " connect the b utmost point of Q2 and Q1 by end of the same name and non-same polarity respectively through resistance R 6 and R5 respectively, two secondary 1 ' 2 ' and the other end of 1 " 2 " connect the negative pole of C2 and the c utmost point of Q2 respectively; Diode D7 and D8 connect e, the b utmost point of Q1 and Q2 respectively; The positive pole of trigger tube DB2 and diode D9, resistance R 2, capacitor C 6 are joined, the b utmost point of its another termination Q2; The negative pole of D9 connects the c utmost point of Q2; The other end of R2, C6 connects the positive pole of C2 and the negative pole of rectifier bridge respectively;

2., open loop protection circuit (3) is to connect like this: connect with load in the former limit of feedback transformer T2, then with the C7 parallel connection; Bidirectional triode thyristor SCR be connected to the negative pole of the negative pole of rectifier bridge and C2 with, its grid meets trigger tube DB1; The other end of DB1 joins with positive pole and the resistance R 1 of electrochemical capacitor C3, the positive pole of another termination rectifier bridge of R1, and the negative pole of C3 connects the negative pole of rectifier bridge; The secondary of T2 is through diode D10, D11 full-wave rectification, and rectification output is with electrochemical capacitor C10 and connect, and the positive pole of C10 connects the grid of SCR through resistance R 7, and capacitor C 9 is with R7 and connect.