CN2318684Y - Constant-current electric supply and long service life fixed digital displayer - Google Patents

Abstract

The utility model relates to a digital displayer having constant-current electric supply, long service life and fixed digital. The utility model comprises a constant current power source, an LED group list and a protective element. The utility model is characterized in that the constant current power source is realized by a capacitor branch which is connected in series with the LED group list, and a piezoresistor is connected in parallel with both ends of the LED group list. Compared with a common digital displayer, the utility model has no constant voltage electric supply and no decode circuit or control circuit. The cost and the volume are reduced, and the reliability is improved. The utility model can conveniently display door plates and seat numbers.

Description

Constant current power supply fixed digital indicator of long-life

The utility model relates to a kind of long-life digital indicator that is applicable to that doorplate, seat number show.

At present, the digital indicator that manufacturer produces, the numeral of its demonstration is type variable, and the user can by certain control method, demonstrate needed number according to the control circuit on the display.The circuit more complicated of this class display, it partly is made up of demonstration, decoding, constant voltage source etc.Wherein the constant voltage source part also comprises iron-core transformer, rectifier cell, voltage control circuit etc.Because use element more, cost is higher, reliability is also lower.This digital indicator is absolutely necessary in a lot of occasions, shows, counts demonstration etc. as clock and watch.Yet in some occasions, as the demonstration of doorplate and seat number, the number of its demonstration all is changeless, and is just uneconomical on the cost if adopt above-mentioned digital indicator, and reliability is also relatively poor.

The utility model is: overcome the deficiency of prior art, provide that a kind of volume is little, cost is low, constant current power supply, long-life, digital changeless digital indicator.

The utility model is achieved in that

Constant current power supply fixed digital indicator of long-life comprises constant current source, light-emitting diode group row, it is characterized in that: constant current source is realized that by capacitive branch this capacitive branch and light-emitting diode group row are in series the incoming transport power supply.

On the basis of such scheme, at the two ends of light-emitting diode group row pressure-active element protection in parallel light-emitting diode group row.

Characteristics of the present utility model are:

1. utilize electric capacity capacitive reactance in alternating circuit Produce capacity current to the power supply of light-emitting diode group row, can satisfy the needs of light emitting diode, reach the effect of perceptual reactive current in the compensation network again, play energy-conservation effect.Because the AC supply voltage major part drops on the electric capacity, the size of loop current is not subjected to the influence of load (light-emitting diode group row) basically, so claim that this kind power supply is the constant current power supply;

2. utilize capacitor to produce the constant-current supply power supply and compare with adopting the power supply of transformer constant voltage, volume, cost greatly reduce, and reliability is improved;

3. because the number of required demonstration immobilizes, can save decoding and control circuit in the traditional monitor, thereby cost is further reduced, reliability further improves;

4. adopt light emitting diode to make the light-emitting component of digital display, low in energy consumption, the brightness height, the life-span is long, can reach 100,000 hours;

5. easy to use.Manufacturer can produce the display single-piece of ten different digitals of 0-9, and the user can select and makes up according to the needed number of controlling oneself.

Accompanying drawing is that the utility model is implemented circuit theory diagrams.Below in conjunction with accompanying drawing the utility model is done a detailed description.

The utility model in actual use, when display incoming transport power supply, owing to electrically contact what is called " shake " phenomenon that can produce off and on, this may make remaining voltage and supply voltage instantaneous value homophase on the capacitor that is in series with the light-emitting diode group row, the two is superimposed as very high voltage (limit situation is two times of crest voltage) and is added in light-emitting diode group and lists, make diode flow through very big electric current, these can very fast damage diode group row.For fear of this situation, need in circuit, to add protecting component.

In the light-emitting diode group row, per 2 light emitting diode inverse parallels are one group in the accompanying drawing, make alternating current be able to by, every group of diode is in series with some, its serial number is decided by the stroke length of its numeral of forming.Voltage dependent resistor (VDR) is parallel to the two ends of light-emitting diode group row, and when overtension, the divided current effect is played in the voltage dependent resistor (VDR) conducting.

Claims (3)

1. constant current power supply fixed digital indicator of long-life comprises capacitor, and light-emitting diode group row and voltage dependent resistor (VDR) is characterized in that: constant current source is realized that by a capacitive branch this capacitive branch is connected the incoming transport power supply with the light-emitting diode group row:

2. display according to claim 1 is characterized in that: light emitting diode inverse parallel, and then series connection.

3. display according to claim 1 is characterized in that: voltage dependent resistor (VDR) in parallel at light-emitting diode group row two ends.

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