The LED lamp drive circuit
The utility model relates to the LED lighting field, refers more particularly to the LED part field, specially refers to the LED illumination driving circuit.
At present, LED is with its long-life, low energy consumption, and pollution-free, color is easy to multiple advantages such as control, thus in street illumination fields such as street lamp, engineerings, the commercial lighting field is extensively promoted the use of.Present LED drive unit is of a great variety, but all is low pressure output.Energy will be through the switch transformer conversion, and when starting the open and close transformer, energy loss is big.Its consumption is compared with the energy on being used in LED at the energy on the drive unit element, and proportion is bigger, and the energy service efficiency is lower, accomplish that 90% all will use up to a hundred components and parts, is significant wastage to raw material, and Installation and Debugging production, and yields is low.The Chinese patent application of announcing number is a kind of led drive circuit of 200810140994.1, because its power factor is low, is not suitable for the LED lamp of at present required high voltage drive.
The utility model content
The purpose of this utility model is to overcome deficiency of the prior art, and a kind of high power factor is provided, the LED lamp drive circuit of no switch transformer.
In order to realize above-mentioned purpose, the technical solution of the utility model provides a kind of LED lamp drive circuit, it comprises that the wave resistance that connects successively comes through stream, overvoltage circuit, EMC filter circuit, rectifier bridge, harmonic wave suppresses circuit, booster circuit, back level current rectifying and wave filtering circuit, constant-current circuit, wherein, wave resistance comes through stream, the external utility grid of overvoltage circuit input, the external LED lamp of constant-current circuit output.
Described wave resistance comes through stream, overvoltage circuit comprises the fuse FUSE that is connected on the circuit, negative tempperature coefficient thermistor NTC, be connected in parallel on the first piezo-resistance VR1 between live wire, the zero line, be connected in parallel on the first piezo-resistance VR2 between live wire, the ground wire, be connected in parallel on the first piezo-resistance VR3 between ground wire, the zero line.
Described EMC filter circuit comprises three grades of X capacitor C 1X, C2X, C3X of eliminating differential mode interference, and two-stage is eliminated common mode inductance L1, the L2 of common mode disturbances, and one-level is eliminated Y capacitor C 4Y, the C5Y of common mode disturbances.
Described common mode inductance L1 be two groups identical around same iron core, the number of turn and phase place, the coil L1a that the coiling direction is opposite, L1b form, described common mode inductance L2 be two groups identical around same iron core, the number of turn and phase place, the coil L2a that the coiling direction is opposite, L2b forms.
Described C1X is connected in parallel on first order common mode inductance L1 front end, and described C2X is connected in parallel between first order common mode inductance L1 and the second level common mode inductance L2, and described C3X is connected in parallel on common mode inductance L2 rear end, the second level.
Described harmonic wave suppresses circuit and comprises control chip IC, boost inductance T, field effect transistor MOS, voltage waveform sampling loop, boost inductance current sampling loop, output voltage sampling loop.
Technique effect of the present utility model, the firstth, the output current constant current is stable, has effectively eliminated the interference of external power supply, makes the LED lamp luminous stable, and no stroboscopic has effectively prolonged the LED life-span; The secondth, owing to adopt high-voltage rectifying output, reduced the electric energy loss that consumes on the LED lamp components, make its efficiency of energy utilization height, reach 92%, the power factor height reaches 99.9%; Three, simple in structure, reduced the parts of assembling, saved switch transformer, reduced because switch transformer starts, the electric energy loss when closed, reach the purpose of energy savings.Simultaneously, because external line voltage span is wide, can produce in batches.
Description of drawings
Fig. 1 is a flow diagram of the present utility model;
Fig. 2 comes through the integrated circuit diagram of stream, overvoltage circuit, rectifier bridge for the wave resistance in the utility model;
Fig. 3 is that the harmonic wave in the utility model suppresses circuit, the integrated circuit diagram of booster circuit.
The 10-rectifier bridge, 20-voltage waveform sampling loop, 30-boost inductance current sampling loop, 40-output voltage sampling loop.
With reference to Fig. 1, wave resistance comes through stream, the civil power of the external 220V of overvoltage circuit input, when civil power comes through stream by wave resistance, during the overvoltage circuit device, this circuit can effectively suppress transient high-current and the transient high voltage in the civil power, make electric current, voltage maintains in the safe range, wave resistance comes through stream, the overvoltage circuit output is connected to EMC filter circuit input, the output of EMC filter circuit is connected with rectifier bridge 10 inputs, and rectifier bridge 10 outputs and harmonic wave suppress circuit, the input of booster circuit links to each other, when civil power suppresses circuit through harmonic wave, during booster circuit, voltage will raise, suppress circuit by harmonic wave, booster circuit and back level current rectifying and wave filtering circuit, will obtain a constant voltage direct current, after described constant voltage direct current outputs to back level current rectifying and wave filtering circuit, output on the LED lamp through a back grade current rectifying and wave filtering circuit again.
With reference to Fig. 2, this figure is that wave resistance comes through stream, overvoltage circuit, the EMC filter circuit, rectifier bridge 10 integrated circuit diagrams, wherein, wave resistance comes through stream, overvoltage circuit comprises the fuse FUSE that is connected on circuit, negative tempperature coefficient thermistor NTC, and be connected in parallel on live wire, the first piezo-resistance VR1 between the zero line is connected in parallel on the second piezo-resistance VR2 between the live wire ground wire, be connected in parallel on the 3rd piezo-resistance VR3 between the zero line ground wire, the EMC filter circuit comprises that three grades are eliminated differential mode interference X capacitor C 1X, C2X, C3X, two-stage is eliminated the common mode inductance L1 of common mode disturbances, L2, one-level is eliminated the Y capacitor C 4Y of common mode disturbances, C5Y.Wherein, the common mode inductance L1 that eliminates common mode disturbances be by two on same iron core, the number of turn is identical with phase place, the coil L1a that the coiling direction is opposite, L1b forms, equally, the common mode inductance L2 that eliminates common mode disturbances also be by two on same iron core, the number of turn is all identical with phase place, the coil L2a that the coiling direction is opposite, L2b forms, and operation principle is when operating current is flowed through common mode inductance L1 or L2, and operating current produces reverse magnetic field and cancels out each other in the inductance coil of same-phase coiling, this moment, electric current only was subjected to the influence of coil resistance, when common mode disturbances electric current flowing through coil, because the same tropism of common mode current understands the induction reactance that produces magnetic field in the same way in coil and increase coil, make coil show as high impedance, produce stronger damping,, reach the purpose of filtering with this attenuation common-mode electric current.
C1X in the elimination differential mode interference X electric capacity in the EMC filter circuit is connected in parallel between the Live line Zero line of first order common mode inductance L1 front, and C2X is connected in parallel between first order common mode inductance and the second level common mode inductance L2, and C3X is connected in parallel on after the common mode inductance L2 of the second level.
With reference to Fig. 3, this figure is the integrated circuit diagram that harmonic wave suppresses circuit, booster circuit, comprise a control chip IC, boost inductance T, a field effect transistor MOS, 30, one the output voltage sampling loops 40 in 20, one boost inductance current samplings of voltage waveform sampling loop loop.Wherein, voltage waveform sampling loop 20 comprises resistance R 2, R3, R4, storage capacitor C6, capacitor C 7, and storage capacitor C6 and capacitor C 7 be the port of external IC chip respectively.Boost inductance current sampling loop 30 comprises boost inductance T, field effect transistor MOS, sampling resistor R8.Output voltage sampling loop 40 comprises capacitor C 8, resistance R 9, R10.Output voltage is through resistance R 9, after the R10 sampling, be input to the IC chip and with after the reference voltage of IC chip internal is compared, export the multiplier of IC chip internal to, be input to multiplier by resistance R 2, R3 voltage divider after sampling by the alternating voltage after rectifier bridge 10 rectifications, the output voltage of multiplier then is proportional to the two product.The source series resistance R 8 of external field effect transistor MOS, the peak current sampling with the boost inductance T of drain electrode is input to IC internal current error amplifier, and for referencial use with the multiplier output voltage.The voltage that produces when peak current reaches threshold value, after just the electric current among the boost inductance T reaches peak value, comparator will stop to drive field effect transistor, at this moment the electric current among the boost inductance T descends along the slope, before electric current in boost inductance T dropped to no-voltage, field effect transistor MOS was in off state.When turn-offing, the energy of storing among the boost inductance T discharges, and is stored among the output capacitor C9 by booster diode.When the current zero-crossing point among the boost inductance T, the secondary winding among the boosted inductance T is detected, send to the startup blanking circuit, the output pwm pulse drives field effect transistor MOS conducting.When field effect transistor MOS conducting, booster diode D1 ends, and energy storage powers to the load among the output capacitance C9.
The utility model protection is the LED lamp drive circuit, so long as those skilled in the art understand the embodiment of the invention, without performing creative labour, only is the replacement of equivalent technology, all belongs to protection scope of the present invention.