Background technology
Along with the continuous development of " green illumination " notion that requires illuminating energy-saving, minimizing environmental pollution, the protection ecological balance, mainly developed country and partly developing national formulation " green illumination plan " successively in the world, and obtained remarkable effect.Be applied to novel, efficient, energy-conserving light source and products such as supporting electric lighting annex, light fixture and controller under " green illumination " environment simultaneously, also constantly weed out the old and bring forth the new, wherein the T5 fluorescent lamp is as a kind of new lighting source, because light efficiency height, photochromic good, life-span are long, the advantage of safety and stable performance, and obtain promotion and application widely.It compares economize on electricity 20%~30% with the T8 fluorescent lamp, and has characteristics such as tube current high conformity, tube voltage drop height, and light efficiency can reach 106Lm/W, life-span 16000 hours.The current electric ballast of T5 fluorescent tube that is used for is generally based on current follow-up circuit, this kind ballast can not suppress the harmonic content in the input current well, crest factor to lamp current requires high, and influenced by complicated factors such as each side parameter and load, its reliability and EMC etc. all are difficult to reach the requirement of T5 fluorescent tube.
In addition, present fluorescent lamp generally adopts cold start, but because the filament impedance is extremely low, and instantaneous large-current appears opening, shorten lamp tube service life, the life-span, particularly high-power fluorescent lamp of also serious danger side of body electric ballast can produce powerful impulse current when starting, more fragile device and equipment, the development of unfavorable electric ballast.
Have, temperature is higher during owing to the T5 fluorescent lamp operation again, and big to circuit and fluorescent tube loss, energy utilization rate is low, occurs blackening phenomena easily, is unfavorable for that people use.
The utility model content
The problem that the utility model need solve provides a kind of reliable operation, possesses pipeline start up by preheating and dividing technology, can regulate inner parameter automatically, prolongs T5 fluorescent lamp and electric ballast life-span, minimizing fluorescent tube blackhead phenomenon, ensures the electric ballast of protecting under circuit long-term stable operation, the multiple abnormal conditions of realization that is used for the T5 fluorescent tube.
Designed a kind of T5 fluorescent tube universal power electric ballast according to the above-mentioned problem that needs to solve, comprise EMC filter circuit, rectification circuit, correcting circuit, change-over circuit that order links to each other, change-over circuit connects a sensing current-limiting circuit that is connected with the T5 fluorescent tube, described sensing current-limiting circuit is made of transformer L3, preheat starting circuit and shunt circuit, transformer L3 is connected with change-over circuit, produce friendship high pressure frequently in order to the AC low-tension that receives the change-over circuit conversion, preheat starting circuit, shunt circuit and T5 fluorescent tube are connected in parallel, and are connected with transformer L3 respectively.
Described preheat starting circuit is formed by resistance R 27 and thermistor V2 serial connection, and thermistor V2 input is connected with transformer L3 output, and the other end of resistance R 27 is connected with shunt circuit with the T5 fluorescent tube.
Described shunt circuit is made up of transformer L4, capacitor C 22, C23, C24, capacitor C 22 and transformer L4 are connected between the T5 fluorescent tube, capacitor C 23, C24 are serially connected with between the primary coil and transformer L3 output of transformer L4, and the secondary winding of transformer L4 is connected with the T5 fluorescent tube.
Between sensing current-limiting circuit and correcting circuit, also be provided with a feedback protection circuit; described feedback protection circuit comprises resistance 22-26; triode Q6; Q7; diode D12; electrochemical capacitor C17; capacitor C 18; the anode of diode D12; one end of resistance R 22 is connected with the source electrode of field effect transistor Q3; one end of the negative electrode of diode D12 and capacitor C 18; one end of resistance R 24 connects; one end of the other end of resistance R 24 and resistance R 23; the positive pole of electrochemical capacitor C17; the base stage of triode Q6 is connected with the collector electrode of triode Q7; the collector electrode of triode is connected with transistor base; the emitter of triode Q3 is connected with correcting circuit by resistance R 26; resistance R 25 is serially connected with between the emitter of the collector electrode of triode Q6 and triode Q7, the emitter of triode Q6; the other end of resistance R 22; the other end of resistance R 23; the negative electrode of electrochemical capacitor C17; the other end ground connection of capacitor C 18.This feedback protection circuit is that the voltage feedback signal that will receive the sensing current-limiting circuit is delivered to and carries out the voltage adjustment in the correcting circuit.
Described EMC filter circuit is accepted outside input power supply, in order to handle the signal of electromagnetic interference, it is connected with rectification circuit, and the voltage after handling is imported in this rectification circuit, this rectification circuit is connected with correcting circuit, and this correcting circuit is used to adjust voltage to provide burning voltage to change-over circuit.
Described change-over circuit connects a sensing current-limiting circuit that is connected with the T5 fluorescent tube, and the sensing current-limiting circuit is made of transformer, preheat starting circuit and shunt circuit,, described preheat starting circuit, shunt circuit are connected in parallel, and are connected with transformer respectively.
The utility model compared with prior art has following beneficial effect:
1. filament carries out abundant preheating before fluorescent lamp starting, prolongs the lamp longevity greatly, improve again equipment performance and moment impact resistance.
2. the technology by the EMC filter circuit can make power consumption very little, and temperature rise is lower, and electromagnetic interference is dropped to minimum level.
3. by " zero current " state behind the technology realization fluorescent lamp operation of shunt circuit, thereby the temperature when having reduced fluorescent lamp operation to a great extent, reduced the loss of circuit and fluorescent lamp, improved rate of energy, while combines with preheat starting circuit, can avoid the phenomenon of the easy blackening of T5 fluorescent tube to take place effectively.
4. correcting circuit can guarantee that this circuit has constant power output characteristic, by IC control and stable oscillation stationary vibration frequency, can regulate inner parameter automatically by the sampling detection that detects input and output, can be adaptive all fluorescent tubes of T5 series, and can in wide-voltage range (100-260V), keep the power of electric ballast constant, thereby guarantee the fluorescent tube brightness.
Embodiment
Below with reference to accompanying drawing embodiment of the present utility model is elaborated:
As shown in Figure 1 and Figure 2, a kind of T5 fluorescent tube universal power electric ballast, comprise EMC filter circuit 1, rectification circuit 2, correcting circuit 3, change-over circuit 4 that order links to each other, change-over circuit 4 connects a sensing current-limiting circuit 5 that is connected with the T5 fluorescent tube, described sensing current-limiting circuit 5 is made of transformer L3, preheat starting circuit 6 and shunt circuit 7, transformer L3 is connected with change-over circuit 4, produce friendship high pressure frequently in order to the AC low-tension that receives change-over circuit 4 conversions, preheat starting circuit 6, shunt circuit 7 are connected in parallel with the T5 fluorescent tube, and are connected with transformer L3 respectively.Between sensing current-limiting circuit 5 and correcting circuit 3, be connected with feedback control circuit 8, between sensing current-limiting circuit 5 and change-over circuit 4, be connected with drive circuit 9, between change-over circuit 4 and correcting circuit 3, be connected with conversion regulating circuit 10.
As shown in Figure 3, EMC filter circuit 1 comprises that capacitor C 1, C3 and filter L1 form, and electric capacity is connected to the input of filter L1, and capacitor C 3 is connected to the output of filter L1, and the output of filter L1 is connected with rectification circuit 2.Rectification circuit 2 is made up of rectifier diode D1-D4, and its output is connected with correcting circuit 3.
Correcting circuit 3 comprises chip U1, power switch pipe Q1, boost inductance L2, booster diode D6, diode D5, D8, D9, electrochemical capacitor C8, C11, capacitor C 10 and resistance R 1-R6, R8-R11,3 pin of chip U1 are by the resistance R 3 of serial connection, R4 is connected with the output of rectification circuit and the end of boost inductance L2, the other end of boost inductance L2 is connected with the anode of booster diode D6 and the drain electrode of power switch pipe Q1, secondary winding one end of boost inductance L2 and 6 pin of chip U1, the negative pole of electrochemical capacitor C8 connects, its other end is connected with 5 pin of chip U1 by resistance R 11, and be connected with an end of capacitor C 11, the positive pole of electrochemical capacitor C8 is connected with 8 pin of chip U1 and the negative electrode of diode D9, the anode of diode D9 and change-over circuit, the negative electrode of diode D5 is connected with the positive pole of electrochemical capacitor C11, the anode of diode D5 is connected with the other end of capacitor C 10 and the negative electrode of diode D8, the minus earth of the anode of diode D8 and electrochemical capacitor C11, the grid of power switch pipe Q1 is connected with 7 pin of chip U1 by resistance R 9, and its source electrode is by resistance R 12 ground connection.At the output of correcting circuit and meet an electrochemical capacitor C12.
Change-over circuit 4 is made up of diode D7, capacitor C 19 and chip U2, diode D7 is serially connected with between 1 pin and 8 pin of chip U2,8 pin of chip U2 are connected with the input of transformer L3 by capacitor C 19,6 pin of chip U2 are connected with the input of transformer L3,5 pin of chip U2 are connected with resistance R 20 in the drive circuit, 7 pin of chip U2 are connected with resistance R 19 in the drive circuit, and 1 pin of chip U2 is connected with correcting circuit, and 2,3,4 pin of chip U2 are connected with the conversion regulating circuit.
Sensing current-limiting circuit 5 is made of transformer L3, preheat starting circuit and shunt circuit, and transformer L3 is connected with change-over circuit, and preheat starting circuit, shunt circuit and T5 fluorescent tube are connected in parallel, and are connected with transformer respectively.Described preheat starting circuit is formed by resistance R 27 and thermistor V2 serial connection, and thermistor V2 input is connected with transformer L3 output, and the other end of resistance R 27 is connected with shunt circuit with output OUTPUT4, and described output is connected with the T5 fluorescent tube.Described shunt circuit is made up of transformer L4, capacitor C 22, C23, C24, capacitor C 22 and transformer L4 are connected between output OUTPUT4, the OUTPUT1, capacitor C 23, C24 are serially connected with between the primary coil and transformer L3 output of transformer L4, and the secondary winding of transformer L4 is connected with output OUTPUT2, OUTPUT3.The input of transformer L3 is connected with change-over circuit, also is connected with drive circuit between the input of transformer L3 and change-over circuit.
Feedback control circuit 8 comprises resistance 22-26, triode Q6, Q7, diode D12, electrochemical capacitor C17, capacitor C 18, the anode of diode D12, one end of resistance R 22 is connected with the source electrode of field effect transistor Q3, one end of the negative electrode of diode D12 and capacitor C 18, one end of resistance R 24 connects, one end of the other end of resistance R 24 and resistance R 23, the positive pole of electrochemical capacitor C17, the base stage of triode Q6 is connected with the collector electrode of triode Q7, the collector electrode of triode is connected with transistor base, the emitter of triode Q3 is connected with correcting circuit by resistance R 26, resistance R 25 is serially connected with between the emitter of the collector electrode of triode Q6 and triode Q7, the emitter of triode Q6, the other end of resistance R 22, the other end of resistance R 23, the negative electrode of electrochemical capacitor C17, the other end ground connection of capacitor C 18.
Drive circuit 9 comprises field effect transistor Q2, Q3, diode D10, D11, resistance R 19, R20, R21, the grid of field effect transistor Q2 is connected with change-over circuit by resistance R 19, its source electrode is connected with the input of transformer L3 by resistance R 21, diode D10 is connected between the resistance R 19, the grid of field effect transistor Q3 is connected with change-over circuit by resistance R 20, and its drain electrode is connected with the input of transformer L3.
Conversion regulating circuit 10 comprises triode Q4, Q5, voltage stabilizing didoe D13, resistance R 13-R18, capacitor C 14-C16, electrochemical capacitor C13, the base stage of triode Q4 is connected with 4 pin of chip U2 by resistance R 18, resistance R 17 and capacitor C 15 are serially connected with between the base stage of 2 pin of chip U2 and triode Q4,3 pin of chip U2 are connected between resistance R 17 and the capacitor C 15, the base stage of triode Q5 is connected with 1 pin of chip U2 by resistance R 14, voltage stabilizing didoe D13, the resistance R 16 of serial connection, and the base stage of triode Q5 is connected with correcting circuit by resistance R 13.
The utility model operation principle is: external power source is input to the EMC filter circuit 1 from N, L end and handles, EMC filter circuit 1 adopts self adaptation zero-current soft switch technology, can be according to load and electrical network characteristic variations, detect arm voltage status and underarm current resonance zero passage in the half-bridge, automatically adjust switching dead time, guarantee under any circumstance to keep soft switch running, it can make T5 fluorescent tube power consumption very little, temperature rise is lower, and electromagnetic interference is dropped to minimum level; After handling, EMC filter circuit 1 is delivered to rectification circuit 2, be delivered to again in the correcting circuit 3, described correcting circuit 3 can guarantee that this circuit has constant power output characteristic, can regulate inner parameter automatically by the sampling detection that detects input and output, thereby can in wide-voltage range (100-260V), keep the power of electric ballast constant, thereby guarantee the fluorescent tube brightness.Adjust the voltage of its institute's rectification circuit that receives 2 conveyings by correcting circuit 30, then adjusted voltage is delivered to change-over circuit 4, the voltage of these change-over circuit 4 received correcting circuits 3 is to keep burning voltage all the time, is in order to direct current is changed the design that alternating current is done by change-over circuit 4 then; Among the transformer L3 in the alternating current input sensing current-limiting circuit 5 that is converted to by change-over circuit 4 again, will exchange low-voltage by transformer L3 and change into ac high voltage, in preheat starting circuit 6 and shunt circuit 7, transformer L3 plays the effect of current limliting at this moment again; Before fluorescent lamp starting, carry out abundant preheating to filament by preheat starting circuit 6, prolong the lamp longevity greatly, improve equipment performance and moment impact resistance, again by " zero current " state behind the technology realization fluorescent lamp operation of shunt circuit 7, thereby the temperature when having reduced fluorescent lamp operation has to a great extent reduced the loss of circuit and fluorescent lamp, has improved rate of energy, while combines with preheat starting circuit, can avoid the phenomenon of the easy blackening of T5 light source to take place effectively.