CN103415124B - LED lamp ballasted by bidirectional thyristor - Google Patents

Abstract

The present invention discloses an LED lamp ballasted by a bidirectional thyristor, comprising a thermal sensing unit, a power regulating unit, a DC LED lamp board and a bridge rectifier, wherein the thermal sensing unit is electrically connected to the bridge rectifier and the DC LED lamp board in sequence, and the power regulating unit is electrically connected to a power source and the bridge rectifier. The thermal sensing unit comprises a thermistor and a current limiting resistor, and the thermistor and the current limiting resistor are coupled. The present invention utilizes the coupled thermistor and the current limiting resistor, so that the change of the current in the current limiting resistor during the power-on process and the size of the heat generated affect the size of the impedance of the thermistor, and then the size of the impedance of the thermistor affects the power regulating unit in the circuit, so that the power of the circuit can be adjusted, and the effect of adjusting the brightness of the LED lamp or ballast is achieved.

Description

A bidirectional thyristor ballast led lamp

technical field

The invention relates to the field of LED lamps, in particular to an LED lamp ballasted by bidirectional thyristors.

Background technique

Lamps made of LEDs have the advantages of low power consumption, low heat generation, and long service life, and have been widely used in various fields. Because the drive circuit of the traditional LED tube or light bulb uses electrolytic capacitors and active components, although the efficiency and output current are stable, the life of the existing LED drive circuit is far less than that of the LED lamp. Often the LED lamp has not been damaged, and the drive circuit has Die early. In order to prolong the life of the LED lamp, the life of the driving circuit needs to be strengthened.

Contents of the invention

The technical problem to be solved by the present invention is to provide an LED lamp ballasted by bidirectional thyristors that can match the lifespan of LEDs against the above-mentioned deficiencies in the prior art.

In order to solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an LED lamp ballasted by a bidirectional thyristor, including a thermal induction unit, a power adjustment unit, a DC LED lamp board and a bridge rectifier. The unit is electrically connected to the bridge rectifier and the DC LED lamp board in turn, and the power adjustment unit is electrically connected to the power supply and the bridge rectifier; the thermal sensing unit includes a thermistor and a current limiting resistor, and the thermistor Coupled with a current limiting resistor; the power adjustment unit includes a nonpolar capacitor, a resistor, a bidirectional trigger diode and a bidirectional thyristor; the nonpolar capacitor and resistor form an RC circuit, and the heat generated by the current limiting resistor changes the temperature sensitive The impedance of the resistor, thereby changing the charge and discharge time of the RC circuit, thereby changing the trigger time of the bidirectional trigger diode to the phase of the bidirectional thyristor; one end of the power supply is connected in series with the thermistor, and the two ends of the thermistor are connected to the power adjustment unit The non-polar capacitor in the circuit is connected in parallel; the non-polar capacitor is connected in parallel with the bidirectional trigger diode, and the resistor is connected in parallel with the bidirectional thyristor in series; the bridge rectifier is connected with the node between the resistor and the bidirectional thyristor, The bridge rectifier is also connected in series with the current limiting resistor to the other end of the power supply; the other two ends of the bridge rectifier are connected to the DC LED lamp board.

In the above technical solution, the thermistor is pasted on the current-limiting resistor through a heat-conducting adhesive; or the thermistor is a chip-type thermistor, the current-limiting resistor is a chip-type current-limiting resistor, and the chip-type thermistor Solder the SMD current limiting resistors on adjacent pads.

In the above technical solution, the thermistor is a negative temperature coefficient thermistor.

An LED lamp ballasted by a bidirectional thyristor, comprising a thermal induction unit, a power adjustment unit and an AC LED lamp board, the thermal induction unit is electrically connected to the AC LED lamp board, and the power adjustment unit is electrically connected to a power supply and the AC LED lamp board; the power adjustment unit includes a non-polar capacitor, a resistor, a triac and a bidirectional thyristor; the non-polar capacitor and the resistor form an RC circuit, and the heat generated by the current-limiting resistor changes the heat The impedance of the sensitive resistor, thereby changing the charging and discharging time of the RC circuit, thereby changing the triggering time of the bidirectional trigger diode to the triac phase; one end of the power supply is connected in series with the thermistor, and the two ends of the thermistor are connected with the power The nonpolar capacitor in the adjustment unit is connected in parallel; the nonpolar capacitor is connected in parallel with the bidirectional trigger diode, and the resistor is connected in series with the bidirectional thyristor and then connected in parallel with the bidirectional trigger diode; the other end of the power supply, the current limiting resistor and the AC LED lamp board connected in series and connected to the node between the resistor and the bidirectional thyristor.

In the above technical solution, the thermistor is pasted on the current-limiting resistor through a heat-conducting adhesive; or the thermistor is a chip-type thermistor, the current-limiting resistor is a chip-type current-limiting resistor, and the chip-type thermistor Solder the SMD current limiting resistors on adjacent pads.

In the above technical solution, the thermistor is a negative temperature coefficient thermistor.

The beneficial effects of the present invention are: the coupled thermistor and the current-limiting resistor are mainly used, so that the current of the current-limiting resistor changes during the energization process, and the amount of heat generated affects the impedance of the thermistor. Then the resistance of the thermistor affects the power adjustment unit in the circuit, so that the power of the circuit can be adjusted, and the effect of adjusting the brightness or ballast of the LED lamp can be achieved. The structure of the present invention is simplified and does not use electrolytic capacitors, inductors, transformers and chips, so the failure rate is much lower than that of LED lamps using traditional switch drive circuits, achieving no radio frequency interference, high brightness, small operating current, simplified structure, and low cost , high circuit reliability and good overall benefits.

Description of drawings

Fig. 1 is the schematic circuit diagram of the first embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of a second embodiment of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

The first embodiment, as shown in Figure 1, is an LED lamp ballasted by a bidirectional thyristor, including a thermal induction unit 1, a power adjustment unit 4, a bridge rectifier 2 and a DC LED lamp board 3, and the thermal induction unit 1 It is connected in series with the bridge rectifier 2 and the DC LED lamp board 3 , and the power adjustment unit 4 is connected to the power supply and the bridge rectifier 2 . Among them, the thermal sensing unit 1 is formed by coupling the negative temperature coefficient thermistor NTC and the current limiting resistance Ra, and the power adjustment unit 4 is formed by connecting the non-polar capacitor Cb, the resistor Rb, the bidirectional trigger diode DIAC and the bidirectional thyristor TRIAC , the bridge rectifier 2 is formed by connecting diodes D1, D2, D3, and D4, and the DC LED lamp panel 3 is composed of a number of light-emitting diode groups connected in series and then connected in parallel. Its circuit connection relationship is as follows: one end of the power supply, the nonpolar capacitor Ca is connected in series with the negative temperature coefficient thermistor NTC, and the nonpolar capacitor Ca and the two ends of the negative temperature coefficient thermistor NTC are connected with the power adjustment unit 4 The non-polar capacitor Cb is connected in parallel; the non-polar capacitor Cb is connected in parallel with the bidirectional trigger diode DIAC, the resistor Rb is connected in series with the bidirectional thyristor TRIAC and then connected in parallel with the bidirectional trigger diode DIAC; the bridge rectifier 2 and the resistor Rb and the bidirectional thyristor The nodes between the TRIACs are connected, and the bridge rectifier 2 is also connected in series with the current limiting resistor Ra and then connected to the other end of the power supply; the other two ends of the bridge rectifier 2 are connected to the DC LED lamp board 3 . In the thermal sensing unit 1, the negative temperature coefficient thermistor NTC is pasted on the current-limiting resistor Ra with heat-conducting adhesive, or the chip-type negative temperature coefficient thermistor NTC and the chip-type current-limiting resistor Ra are pasted together. Solder on pads adjacent to each other. When the power is turned on, the current of the bridge rectifier 2 and the DC LED lamp board 3 passes through the thermal induction unit 1 composed of the current limiting resistor Ra and the negative temperature coefficient thermistor NTC. The higher the heat, the smaller the impedance of the negative temperature coefficient thermistor NTC close to the current limiting resistor Ra, the nonpolar capacitance Ca connected to the negative temperature coefficient thermistor NTC and the nonpolarity in the power adjustment unit 4 The charging and discharging time of RC composed of capacitor Cb and resistor Rb becomes longer, and the hysteresis bidirectional trigger diode DIAC triggers the phase of bidirectional thyristor TRIAC, which can automatically increase or decrease the power of the entire LED lamp ballasted by bidirectional thyristor, so as to Stabilize the brightness or achieve the purpose of ballasting the DC LED lamp board 3 .

The second embodiment, as shown in Figure 2, is an LED lamp ballasted by a bidirectional thyristor, including a thermal induction unit 1, a power adjustment unit 4, and an AC LED lamp board 5, and the thermal induction unit 1 and the AC LED lamp board 5 are connected in series, and the power adjustment unit 4 is connected to the power supply. Among them, the thermal sensing unit 1 is formed by coupling the negative temperature coefficient thermistor NTC and the current limiting resistance Ra, and the power adjustment unit 4 is formed by connecting the non-polar capacitor Cb, the resistor Rb, the bidirectional trigger diode DIAC and the bidirectional thyristor TRIAC , the AC LED lamp panel 5 is composed of several groups of two light-emitting diodes connected in parallel and then connected in parallel again. One end of the power supply, the non-polar capacitor Ca is connected in series with the negative temperature coefficient thermistor NTC, and the non-polar capacitor Ca and the two ends of the negative temperature coefficient thermistor NTC are connected in parallel with the non-polar capacitor Cb in the power adjustment unit 4; The nonpolar capacitor Cb is connected in parallel with the bidirectional trigger diode DIAC, and the resistor Rb is connected in series with the bidirectional thyristor TRIAC and then connected in parallel with the bidirectional trigger diode DIAC; the other extreme of the power supply, the current limiting resistor Ra, is connected in series with the AC LED lamp board 5 And connected to the node between the resistor Rb and the bidirectional thyristor TRIAC. In the thermal sensing unit 1, the negative temperature coefficient thermistor NTC is pasted on the current-limiting resistor Ra with heat-conducting adhesive, or the chip-type negative temperature coefficient thermistor NTC and the chip-type current-limiting resistor Ra are pasted together. Solder on pads adjacent to each other. When the power is turned on, the current of the bridge rectifier 2 and the DC LED lamp board 3 passes through the thermal induction unit 1 composed of the current limiting resistor Ra and the negative temperature coefficient thermistor NTC. The higher the heat, the smaller the impedance of the negative temperature coefficient thermistor NTC close to the current limiting resistor Ra, the nonpolar capacitor Ca connected in series with the negative temperature coefficient thermistor NTC, and the nonpolar capacitor Ca in the power adjustment unit 4 The charging and discharging time of the RC composed of the memory capacitor Cb and the resistor Rb becomes longer, and the phase triggered by the hysteresis bidirectional trigger diode DIAC to the bidirectional thyristor TRIAC can automatically increase or decrease the power of the entire LED lamp ballasted by the bidirectional thyristor. To stabilize the brightness or achieve the purpose of ballasting the AC LED lamp board 5 .

The working principle of this kind of LED lamp ballasted by bidirectional thyristor is as follows: after the power is turned on, the greater the current passing through the current limiting resistor Ra, the higher the heat generated, making the resistance of the negative temperature coefficient thermistor NTC becomes smaller, because the non-polar capacitor Ca connected to the negative temperature coefficient thermistor NTC is connected in parallel with the non-polar capacitor Cb in the power adjustment unit 4, so the negative temperature coefficient thermistor NTC, the non-polar capacitor Ca and the non-polar capacitor Cb The total capacitance of the capacitor becomes larger, so that the charging and discharging time of the RC formed by the total capacitance and the resistor Rb becomes longer, and the hysteresis of the phase triggered by the bidirectional trigger diode DIAC to the bidirectional thyristor TRIAC reduces the power of the whole lamp; when the whole lamp When the power of the current-limiting resistor Ra is reduced, the current through the current-limiting resistor Ra becomes smaller, and the heat generated becomes less, so that the impedance of the negative temperature coefficient thermistor NTC becomes larger, because the non-polar capacitor Ca connected to the negative temperature coefficient thermistor NTC, and The nonpolar capacitor Cb in the power adjustment unit 4 is connected in parallel, so the total capacitance of the negative temperature coefficient thermistor NTC, the nonpolar capacitor Ca and the nonpolar capacitor Cb becomes smaller, and the RC formed by the total capacitance and the resistor Rb is charged. The discharge time is shortened, and the phase triggered by the two-way trigger diode DIAC and the two-way thyristor TRIAC is moved forward, so that the power of the whole lamp is increased, and the above actions are repeated; so as to automatically increase or decrease the power of the whole lamp to stabilize the brightness or to ( DC or AC) LED light board achieves the purpose of ballast.

The above-mentioned power supply can be commercial power, that is to say, the LED lamp ballasted by bidirectional thyristor can be directly connected to 220V commercial power.

Because the structure of the present invention is simplified and does not use electrolytic capacitors, inductors, transformers and chips, the failure rate is far lower than that of LED lights using traditional switch drive circuits, achieving no radio frequency interference, high brightness, low operating current, low cost, and low cost. It has the advantages of high reliability and good overall effect.

The above embodiments are only intended to illustrate rather than limit the present invention, so all equivalent changes or modifications made according to the methods described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims (4)

1. one kind with the LED of bidirectional triode thyristor ballast, it is characterized in that: include thermoinduction unit, power adjustment unit, direct-current LED lamp plate and bridge rectifier, described thermoinduction unit is electrically connected with successively with bridge rectifier, direct-current LED lamp plate, and described power adjustment unit is electrically connected with power supply and described bridge rectifier；Described thermoinduction unit includes that critesistor and current-limiting resistance, described critesistor and current-limiting resistance are coupled；Described power adjustment unit includes polarity free capacitor Cb, resistance, bidirectional trigger diode and bidirectional triode thyristor；Polarity free capacitor Ca, described polarity free capacitor Cb and resistance composition RC circuit, the heat produced by current-limiting resistance, change the impedance of critesistor, thus change the discharge and recharge time of RC circuit, thus change the bidirectional trigger diode triggered time to bidirectional triode thyristor phase place；The one of power supply is extreme, polarity free capacitor Ca concatenates with critesistor, and this polarity free capacitor Ca is in parallel with the polarity free capacitor Cb in power adjustment unit again with the two ends of critesistor；This polarity free capacitor Cb is in parallel with bidirectional trigger diode again, and resistance is in parallel with this bidirectional trigger diode again after connecting with bidirectional triode thyristor；Node between bridge rectifier with resistance with bidirectional triode thyristor is connected, and this bridge rectifier is connected another of power source with current-limiting resistance after also concatenating extreme；The other two ends of this bridge rectifier connect direct-current LED lamp plate；Described critesistor is negative tempperature coefficient thermistor.

A kind of LED with bidirectional triode thyristor ballast the most according to claim 1, it is characterised in that: described critesistor is pasted on described current-limiting resistance by heat-conducting glue；Or described critesistor is pasted sheet type thermistor, described current-limiting resistance is SMD current-limiting resistance, and this pasted sheet type thermistor and SMD current-limiting resistance are welded on the pad being mutually adjacently.

3. one kind with the LED of bidirectional triode thyristor ballast, it is characterized in that: include thermoinduction unit, power adjustment unit and AC LED lamp plate, described thermoinduction unit is electrically connected with AC LED lamp plate, and described power adjustment unit is electrically connected with power supply and described AC LED lamp plate；Described power adjustment unit includes polarity free capacitor, resistance, bidirectional trigger diode and bidirectional triode thyristor；Polarity free capacitor Ca, described polarity free capacitor Cb and resistance composition RC circuit, the heat produced by current-limiting resistance, change the impedance of critesistor, thus change the discharge and recharge time of RC circuit, thus change the bidirectional trigger diode triggered time to bidirectional triode thyristor phase place；The one of power supply is extreme, polarity free capacitor Ca concatenates with critesistor, and this polarity free capacitor Ca is in parallel with the polarity free capacitor Cb in power adjustment unit again with the two ends of critesistor；This polarity free capacitor Cb is in parallel with bidirectional trigger diode again, and resistance is in parallel with this bidirectional trigger diode again after connecting with bidirectional triode thyristor；Another of power supply is extreme, current-limiting resistance concatenates and be connected to the node between resistance and bidirectional triode thyristor with AC LED lamp plate；Described critesistor is negative tempperature coefficient thermistor.

A kind of LED with bidirectional triode thyristor ballast the most according to claim 3, it is characterised in that: described critesistor is pasted on described current-limiting resistance by heat-conducting glue；Or described critesistor is pasted sheet type thermistor, described current-limiting resistance is SMD current-limiting resistance, and this pasted sheet type thermistor and SMD current-limiting resistance are welded on the pad being mutually adjacently.