CN201332523Y

CN201332523Y - LED step-down drive circuit absorbing surge

Info

Publication number: CN201332523Y
Application number: CNU2009200667221U
Authority: CN
Inventors: 汤乃申; 汤征宁
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-01-09
Filing date: 2009-01-09
Publication date: 2009-10-21
Anticipated expiration: 2019-01-09

Abstract

A LED step-down drive circuit absorbing surge, wherein current is commutated by using capacitance step-down via commutation circuit, then is wave-filtered into DC via a wave filter capacitance, the surge current of the DC is absorbed via an surge limit capacitance series voltage regulator such as constant voltage diode, then both ends of the constant voltage diode connects with a LED lamp after limit capacitance. The LED lamp is a constant voltage element, voltage is constant, the circuit steps-down via a capacitance, in steady-state, working current is determined with size of the capacitance of, addition of voltage drop through the LED limit resistance of max working current and voltage of the LED is designed to not higher than steady voltage of the voltage regulator, thereby confirming the voltage regulator does not work in steady-state and reducing power consumption in steady-state. The utility model prevents step-down surge current from damaging LED elements, conserves low consumption of capacitance step-down, provides simple and practical circuit, saves energy comparing with present resistance-capacitance of LED lamps, is simpler and more reliable than switch power drive LED lamps without high-frequency interference.

Description

A kind of LED capacitance decompression drive circuit that absorbs surge

[technical field]

The utility model relates to a kind of LED capacitance decompression drive circuit that absorbs surge.

[background technology]

Known LED capacitance decompression drive circuit, for preventing that surge current from damaging the LED lamp, just seal in a resistance with limit inrush currents when input, so not only power consumption is very big, and because surge voltage is very big, though resistance is bigger, but surge current is still very big, and is first through voltage stabilizing after the rectification that also has, again current stabilization driving LED lamp, so not only circuit complexity but also power consumption are also big, so led drive circuit mostly is the Switching Power Supply made from integrated circuit.

[utility model content]

The utility model uses capacitance decompression through the rectification circuit rectification earlier, be filtered into direct current through filter capacitor again, this direct current elder generation absorbs surge current via semiconductor device such as the voltage stabilizing didoe that the series connection of surge current-limiting resistance has stabilized voltage characteristic, consider that surge current is very big, optionally use high-power voltage-stabiliser tube, their transient working electric current is bigger, the surge current-limiting resistance is just lessly available like this, steady state power consumption is also less, then on two terminations of this pipe through the LED of current-limiting resistance lamp. and the LED lamp is a constant voltage elements, voltage is constant, this circuit is by capacitance decompression, when stable state, operating current is mainly decided by the size of electric capacity, and maximum operating currenbt flows through the pressure drop of LED current-limiting resistance, adds that the voltage of LED lamp is designed into the burning voltage that is not more than voltage-stabilizing device, voltage-stabilizing device is not worked when having guaranteed stable state, and this has also reduced steady state power consumption.

As seen by above-mentioned, the utility model had both solved surge current effectively to the LED damage of elements, had kept the low-power consumption of capacitance decompression again, and circuit is simple relatively, and its obvious practicability is arranged.

[description of drawings]

Following accompanying drawing describes content of the present utility model in detail.

Fig. 1 is a functional-block diagram of the present utility model.AC power, can be that electric main is through decompression capacitor C1 (1) step-down, input to rectification circuit (2), rectification circuit output is after filter capacitor C (2) is filtered into direct current, the semiconductor device D (5) that has stabilized voltage characteristic through surge current-limiting resistance R1 (4) series connection has absorbed surge current, string has the LED lamp (7) of LED current-limiting resistance R2 (6) on two terminations of voltage-stabilizing device D. the burning voltage of voltage-stabilizing device D, be not more than the maximum voltage drop sum of LED current-limiting resistance and LED lamp when stable state, the voltage-stabiliser tube power consumption of not working is just little during stable state like this. when the dielectric resistance of C1 is big, accelerate discharge at power cut-off the time, and can be at C1 two ends suitable resistance in parallel.

Fig. 2 is an electrical schematic diagram of the present utility model, and wherein rectification circuit (2) is by D1, D2, and D3, the bridge rectifier that D4 forms, the LED lamp is managed the lamp of forming by 3 LED that are connected into one group of 3 groups of parallel connection.

Fig. 3 is another electrical schematic diagram of the present utility model, and wherein rectification circuit (2) is by D5, the half-wave voltage doubler that D6 forms, and, the lamp .. that the LED lamp is made up of the LED pipe of 3 series connection

[embodiment]

Following embodiment explains in conjunction with the accompanying drawings.

Fig. 2 is an embodiment of the present utility model, and C1 is 1 μ f electric capacity, D1, D2, D3, D4 is diode 4007, and C2 is 100 μ f electric capacity, and R1 is 100 Ω resistance, D is the 15V/1W voltage-stabiliser tube, and R2 is 68 Ω resistance, and 9 LED light-emitting diodes all are low power LEDs, is a very practical lamp.

Fig. 2 is another embodiment of the present utility model, be hour to use when the LED lamp current, C1 is 0.68 μ f electric capacity, D5, D6, be diode 4007, C2 is 100 μ f electric capacity, and R1 is 100 Ω resistance, D is the 15V/1W voltage-stabiliser tube, R2 is 200 Ω resistance, and 3 LED light-emitting diodes all are low power LEDs, has formed a mini light night.

In sum, the utility model has solved the capacitance decompression surge current effectively to the LED damage of elements, has kept the low-power consumption of capacitance decompression, circuit is simple and practical, contrast the LED lamp reliable and energy-saving of known resistance-capacitance depressurization, more simple and reliable than Switching Power Supply driving LED lamp, no High-frequency Interference.

Claims

1, a kind of LED capacitance decompression drive circuit that absorbs surge, it is characterized in that comprising decompression capacitor C1 (1), rectification circuit (2), filter capacitor C2 (3), surge current-limiting resistance R1 (4) has the semiconductor device D (5) of stabilized voltage characteristic, LED current-limiting resistance R2 (6), with LED lamp (7), AC power one end is behind C1 (1), and two ends connect the input of rectification circuit (2) simultaneously, and it is exported two ends and meets C2 (3), after the termination R1 (4) of C2 is connected in series D (5) again, the other end that meets C2 is as common port, and D connects the end that R2 (6) is connected in series LED lamp (7) then again with the contact of R1, another termination common port of LED lamp.

2, according to claim 1, a kind of LED capacitance decompression drive circuit that absorbs surge is characterized in that described surge current-limiting resistance R1 (4), should be limited within the working range of the semiconductor device D (5) with stabilized voltage characteristic greatly to making decompression capacitor C1 (1) go up the surge current that produces.

3, according to claim 1, a kind of LED capacitance decompression drive circuit that absorbs surge is characterized in that described semiconductor device D (5) with stabilized voltage characteristic, and its burning voltage should be not less than LED current-limiting resistance R2 (6) and LED lamp (7) maximum voltage drop sum when stable state.

4 according to claim 1, and a kind of LED capacitance decompression drive circuit that absorbs surge is characterized in that described rectification circuit (2), can be made up of full-wave bridge rectifier circuit or half-wave voltage doubler.，

5, according to claim 1, a kind of LED capacitance decompression drive circuit that absorbs surge is characterized in that described LED lamp (7) can be by single led pipe or the series connection of a plurality of LED pipe, and parallel connection or series-parallel connection are formed.