CN202363086U - Automobile air-conditioning liquid crystal backlight control circuit - Google Patents
Automobile air-conditioning liquid crystal backlight control circuit Download PDFInfo
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- CN202363086U CN202363086U CN2011204440619U CN201120444061U CN202363086U CN 202363086 U CN202363086 U CN 202363086U CN 2011204440619 U CN2011204440619 U CN 2011204440619U CN 201120444061 U CN201120444061 U CN 201120444061U CN 202363086 U CN202363086 U CN 202363086U
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- Arrangements Of Lighting Devices For Vehicle Interiors, Mounting And Supporting Thereof, Circuits Therefore (AREA)
Abstract
The utility model refers to an automobile air-conditioning liquid crystal backlight control circuit, comprising a resistor Ra, a triode TR1, a sampling resistor Rb and a feedback triode TR2. One end of the sampling resistor Rb and a base electrode of the feedback triode TR2 are in connection with an emitter electrode of the main circuit triode TR1 which controls backlight current; the other end of sampling resistor Rb is in ground connection with an emitter electrode of the triode TR2. A collector electrode of the feedback triode TR2 is in connection with a base electrode of the main circuit triode TR1 which controls backlight current. When a power supply of a saloon car changes between a scope of DC9V- DC16V, liquid crystal brightness of the utility model has no obvious change.
Description
Technical field
The utility model relates to a kind of control device, particularly a kind of automobile air conditioner LCD backlight control circuit.
Background technology
At present, a lot of automotive air-conditioning controllers adopt liquid crystal display displays air-conditioning state, and most of LED that adopts is as LCD backlight lamp source aspect LCD backlight, and the characteristics of LED are that color is much available, and ratio is from vehement Lantern Festival ability.But when requiring between power supply DC9V-DC16V owing to automobile, parts are in proper working order.And adopt method LED brightness on so wide power supply of existing resistance in series current limliting to change too greatly.
As shown in Figure 1, the electric current of every paths of LEDs is Iled=(V-0.7-Vled)/R, and wherein: Iled is the electric current of every paths of LEDs; V is that automobile provides power supply; 0.7 be the forward voltage drop of diode; R is the current-limiting resistance of every paths of LEDs; Vled is the forward voltage drop of LED, and for the LED that confirms color, Vled is a definite value basically; V is an automobile power source, and its value is between DC9V and DC16V, and as V during at DC9V and during DC16V, Iled alters a great deal.
The utility model content
The technical matters that the utility model will solve provides a kind of automobile air conditioner LCD backlight control circuit.
For achieving the above object, the technical scheme of the utility model is following:
A kind of automobile air conditioner LCD backlight control circuit comprises resistance R a and triode TR1; It is characterized in that; Also comprise sampling resistor Rb, feedback triode TR2; The base stage of the end of described sampling resistor Rb and feedback triode TR2 links to each other with the triode TR1 emitter of main circuit control backlight electric current, the grounded emitter of the other end of sampling resistor Rb and feedback triode TR2; The base stage of the triode TR1 of the collector of feedback triode TR2 and main circuit control backlight electric current is joined.
Through technique scheme, the beneficial effect of the utility model is:
When the brightness of the utility model liquid crystal changed in the scope of power supply from DC9V to DC16V of car, liquid crystal brightness did not have significant change.
Description of drawings
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art; To do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below only is some embodiment of the utility model, for those of ordinary skills; Under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
Fig. 1 tradition LED current control circuit figure:
Fig. 2 is the circuit diagram of the utility model.
Embodiment
For technological means, creation characteristic that the utility model is realized, reach purpose and be easy to understand understanding with effect, below in conjunction with concrete diagram, further set forth the utility model.
Referring to shown in Figure 2, the utility model comprises resistance R a, triode TR1; Also comprise a sampling resistor Rb, feedback triode TR2; The base stage of the end of described sampling resistor Rb and feedback triode TR2 links to each other with the triode TR1 emitter of main circuit control backlight electric current, the grounded emitter of the other end of sampling resistor Rb and feedback triode TR2; The base stage of the triode TR1 of the collector of feedback triode TR2 and main circuit control backlight electric current is joined.
O.7V, the electric current I led=O.7/Rb/n of every paths of LEDs in the utility model is the base stage of TR2 and the pressure drop of emitter, the i.e. forward voltage drop of the PN utmost point; Rb is a current sampling resistor, is used for the electric current of led circuit backlight is converted into voltage the base current of control TR2; Control the collector current of TR2 like this; Shunt the base current of TR1, control the collector current of TR1 like this, i.e. the total current of LED backlight.The variation relation of the electric current of LED and automobile power source is little like this.As long as choosing is to the size of Rb, during from the range of DC9V-DC16V, the current value that just can control every paths of LEDs lamp is constant at power supply, and like this at power supply during from the range of DC9V-DC 16V during variation, backlight illumination also remains unchanged.
More than show and described ultimate principle of the utility model and the advantage of principal character and the utility model.The technician of the industry should understand; The utility model is not restricted to the described embodiments; The principle of describing in the foregoing description and the instructions that the utility model just is described; Under the prerequisite that does not break away from the utility model spirit and scope, the utility model also has various changes and modifications, and these variations and improvement all fall in the utility model scope that requires protection.The utility model requires protection domain to be defined by appending claims and equivalent thereof.
Claims (1)
1. an automobile air conditioner LCD backlight control circuit comprises resistance R a and triode TR1; It is characterized in that; Also comprise sampling resistor Rb, feedback triode TR2; The base stage of the end of described sampling resistor Rb and feedback triode TR2 links to each other with the triode TR1 emitter of main circuit control backlight electric current, the grounded emitter of the other end of sampling resistor Rb and feedback triode TR2; The base stage of the triode TR1 of the collector of feedback triode TR2 and main circuit control backlight electric current is joined.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204440619U CN202363086U (en) | 2011-11-10 | 2011-11-10 | Automobile air-conditioning liquid crystal backlight control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204440619U CN202363086U (en) | 2011-11-10 | 2011-11-10 | Automobile air-conditioning liquid crystal backlight control circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202363086U true CN202363086U (en) | 2012-08-01 |
Family
ID=46574256
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011204440619U Expired - Lifetime CN202363086U (en) | 2011-11-10 | 2011-11-10 | Automobile air-conditioning liquid crystal backlight control circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202363086U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102903338A (en) * | 2012-10-22 | 2013-01-30 | 上海福太隆汽车电子科技有限公司 | Liquid crystal backlight control circuit for automobile air conditioner |
| CN111098781A (en) * | 2018-10-25 | 2020-05-05 | 杭州三花研究院有限公司 | Control device and control method |
-
2011
- 2011-11-10 CN CN2011204440619U patent/CN202363086U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102903338A (en) * | 2012-10-22 | 2013-01-30 | 上海福太隆汽车电子科技有限公司 | Liquid crystal backlight control circuit for automobile air conditioner |
| CN111098781A (en) * | 2018-10-25 | 2020-05-05 | 杭州三花研究院有限公司 | Control device and control method |
| CN111098781B (en) * | 2018-10-25 | 2021-06-18 | 杭州三花研究院有限公司 | Control device and control method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20120801 |
|
| CX01 | Expiry of patent term |