CN2275781Y

CN2275781Y - Traffic signal lamp bulb life prolonging apparatus

Info

Publication number: CN2275781Y
Application number: CN 96247413
Authority: CN
Inventors: 赵伯南
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-07
Filing date: 1996-12-07
Publication date: 1998-03-04
Anticipated expiration: 2006-12-07

Abstract

The utility model relates to a device which can extend the service life of a lamp bulb of a traffic signal lamp. A circuit plate of a current limiting circuit of a starting current of the lamp bulb is arranged in a box, and is filled with epoxy resin to be sealed into a whole body. The current limiting circuit is mainly composed of a field effect transistor, a low value voltage comparator, a valve circuit, a charge circuit, and a discharge circuit. The output voltage of the charge circuit compares with the voltage of a valve, which leads the comparator to output a low level or a high level. The field effect transistor is controlled to stop or conduct a region, which leads the instant average impact current to be reduced when the lamp bulb is started. The service life of the lamp bulb can be extended by 5-10 times. The device which can extend the service life of a lamp bulb has the advantages of simple structure, low cost, and stable performance. The work load for replacing lamp bulbs of a traffic signal lamp is reduced.

Description

Traffic lights bulb life extender

The utility model relates to bulb starting current current limiting technique, particularly a kind of bulb life extender that is used for traffic lights.

Existing traffic lights bulb is the ordinary incandescent lamp bubble that adopts 100W, and the filament cold resistance specific thermal resistance of this bulb is little more than 10 times, and the electric current when that is to say starting is bigger more than 10 times than the electric current after stable.Because the characteristics of traffic signals are constantly to open and close, and promptly red, green light is alternately lighted, open and close every day reach hundreds of times more than again.Under frequent like this cranking current pulse, the filament of incandescent lamp bulb is easy to aging and damages.Be about 2 months the average life for general common 100W incandescent lamp bulb.This shows that the whole nation workload that changes the bulb of each city traffic signal lamp is very big, and will use engineering overall height idle job when changing the bulb, for some small cities for want of engineering truck then change the bulb just more difficult.So be difficult to guarantee the operate as normal of traffic signals, the traffic order in city is caused harmful effect.

The purpose of this utility model is to provide a kind of simple in structure, traffic lights bulb life extender that cost is low, stable and reliable for performance, it can make the impulse current of ordinary incandescent lamp bubble point bright moment reduce to bottom line, thereby prolongs 5 to 10 times of useful lifes of bulb.

The utility model purpose is achieved in that a kind of traffic lights bulb life extender, a bulb life extender is housed in the traffic signals light fixture, the structure of this bulb life extender is that bulb starting current current-limiting circuit wiring board is housed in plastic casing, filling in the box space with epoxy resin, to make it to become a sealing whole, and sealing is box-packed two input leads that connect the alternating current 220V external power and two output leads that are connected bulb.Bulb starting current current-limiting circuit comprises: bridge rectifier and D.C. regulated power supply; By ordinary incandescent lamp W, high back-pressure high-power FET T _r, sample resistance R ₆The major loop that is composed in series; Low voltage comparator IC output 3 and field effect transistor T _rThe control grid is connected; Low voltage comparator IC positive input 2 is connected with the valve circuit output; Field effect transistor T _rSource electrode and with reference to being connected to charge circuit between the ground, its output is connected with low voltage comparator IC negative input 4.Described valve circuit is by resistance R ₂, diode D ₆Be composed in series, be attempted by the D.C. regulated power supply output.Described charge circuit is by resistance R ₅, capacitor C ₂Be composed in series.

The positive input 2 of low voltage comparator IC has a stable threshold voltage, and the charge circuit output end voltage makes low voltage comparator IC output low level of 3 outputs or high level by comparison, thereby controls high back-pressure high-power FET T _rEnd or conducting, the average impulse current of bulb is significantly reduced, reach the purpose of effective prolongation bulb service life.

Advantage of the present utility model is that circuit structure is simple, cost is low, stable and reliable for performance, metering function fast and significantly, the impulse current that can make incandescent lamp bulb light moment cuts to bone, thereby reach 5 to 10 times the useful life that prolongs bulb.Reduced the workload that city traffic signal lamp changes the bulb widely, commander creates good working environment for urban traffic signal.

Fig. 1 is the utility model structural representation.

Fig. 2 is the utility model bulb starting current current-limiting circuit schematic diagram.

Fig. 3 is field effect transistor T shown in Figure 2 _rSource electrode A point voltage oscillogram.

Fig. 4 is a low voltage comparator IC output B point voltage oscillogram shown in Figure 2.

Below by embodiment the utility model is further elaborated.

With reference to shown in Figure 1, be contained in the bulb life extender in the existing traffic signals light fixture, form by epoxy resin filler 11 in square plastic box 12, bulb starting current current-limiting circuit wiring board 14 and the box 12, be respectively equipped with two alternating current 220V input leads 15 and two output leads 13 that join with the bulb electrode in box 12 both sides.

Bulb starting current current-limiting circuit is referring to shown in Figure 2.Diode D ₁-D ₄Form bridge rectifier, the 220V alternating voltage is become pulsating dc voltage.This direct voltage is added to by high-power of the high back-pressure of bulb W, VMOS should manage T _rWith current sampling resistor R ₆The major loop two ends that are composed in series.Manage to control field effect transistor T _rElectric current, even if reached the purpose that control flows is crossed the bulb electric current.Resistance R ₁, voltage stabilizing didoe D ₅, capacitor C ₁Composition+10V D.C. regulated power supply is attempted by the bridge rectifier output.IC is the low voltage comparator, and the valve circuit that is attempted by the D.C. regulated power supply output is by resistance R ₂With diode D ₆Be composed in series, at diode D ₆Two ends produce the threshold voltage of one+0.7V and are added on the low voltage comparator IC positive input 2.Current sampling resistor R ₆Be connected on VMOS field effect transistor T _rSource electrode and with reference between the ground.By resistance R ₅Hold C with circuit ₂The charge circuit of polyphone is also received resistance R ₆Two ends.Resistance R 5 and capacitor C ₂Contact be connected with low voltage comparator IC reverse input end 4.Current sampling resistor R ₆On voltage through resistance R ₅To capacitor C ₂Capacitor C is worked as in charging ₂Both end voltage is during greater than the 0.7V threshold voltage, and low voltage comparator IC output 3 is a low level, and this voltage is through a little resistance resistance R ₃Directly be added to VMOS field effect transistor T _rThe control grid on, make field effect transistor T _rEnd.At this moment, there is not electric current to flow through VMOS field effect transistor T _rAnd resistance R ₆, capacitor C ₂On electric charge pass through resistance R ₅, R ₆Discharge, capacitor C ₂On voltage reduce.Work as capacitor C ₂On voltage when being reduced to less than the 0.7V threshold values, comparator IC output 3 transfers high level to, VMOS field effect transistor T _rSaturation conduction.So just form a circulation by, conducting.Cycle period length depends on resistance R ₅, capacitor C ₂Size, generally get RC≤1MS.

When the moment that bulb W lights, impulse current is very big, resistance R ₆On voltage drop also become very big, will produce a sheet ofly like this by, conducting region, Fig. 3 represents VMOS field effect transistor T this moment _rSource electrode A point voltage waveform, Fig. 4 are represented VMOS field effect transistor T this moment _rThe voltage waveform that control grid B is ordered.Owing to a sheet of cut-off region occurs, bulb average impulse current of starting moment is significantly reduced, thereby, reach the purpose that prolongs bulb service life effectively.

Resistance R shown in Figure 2 ₃, R ₄Be VMOS field effect transistor T _rGrid circuit.Be connected on VMOS field effect transistor T _rDrain electrode is to the piezo-resistance R with reference to ground _yBe protection field effect transistor T _rAvoiding the moment overvoltage damages.Adopt high back-pressure high-power FET owing to adjust control valve, make control circuit greatly simplify, reliability also improves greatly.

Claims

1, a kind of traffic lights bulb life extender is equipped with a bulb life extender in the traffic signals light fixture, it is characterized in that:

(1) bulb starting current current-limiting circuit wiring board is housed in plastic casing, it is whole to make it to become a sealing with space in the epoxy resin filling box;

(2) bulb starting current current-limiting circuit comprises:

Bridge rectifier and D.C. regulated power supply;

By ordinary incandescent lamp W, high back-pressure high-power FET T _r, sample resistance R ₆The major loop that is composed in series;

Low voltage comparator IC output 3 and field effect transistor T _rThe control grid is connected;

Low voltage comparator IC positive input 2 joins with the valve circuit output;

Field effect transistor T _rSource electrode and with reference to being connected to charge circuit between the ground, its output and low voltage comparator IC negative input 4 join.

2, bulb life extender according to claim 1 is characterized in that described valve circuit is by resistance R ₂, diode D ₆Polyphone is formed, and is attempted by the D.C. regulated power supply output.

3, bulb life extender according to claim 1 is characterized in that described charge circuit is by resistance R ₅, capacitor C ₂Be composed in series.