CN209402627U - Backlight constant-current circuit - Google Patents
Backlight constant-current circuit Download PDFInfo
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- CN209402627U CN209402627U CN201920229807.0U CN201920229807U CN209402627U CN 209402627 U CN209402627 U CN 209402627U CN 201920229807 U CN201920229807 U CN 201920229807U CN 209402627 U CN209402627 U CN 209402627U
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- backlight
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- lamp bar
- current
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Abstract
The utility model relates to a kind of backlight constant-current circuit, voltage of the voltage Voltage stabilizing module according to the anode of backlight lamp bar, the cathode voltages of stability contorting optocoupler photophore.Simultaneously; the cathode of current control module connection backlight of television lamp bar; back facet current can be controlled in a stable range according to the cathode voltage and backlight adjustment signals of stable control optocoupler photophore, prevent back facet current from situations such as overshooting or fluctuating occur, be effectively protected backlight lamp bar.
Description
Technical field
The utility model relates to backlights to export control technology field, more particularly to a kind of backlight constant-current circuit.
Background technique
In the backlight output circuit of television set, alternating current is acquired generally by transformer, alternating current is converted into backlight
The output voltage of item.Meanwhile backlight of television output circuit further includes the control chip controlled back facet current and control
Optocoupler, wherein it controls the section ports of chip and is connected by the control optocoupler light-receiving device of conducting, according to the work relationship of connection,
It controls chip and stability contorting is carried out to back facet current.
However, will affect the work relationship of control chip when the case where voltage falls suddenly occurs in control optocoupler, causing
Back facet current overshoot or fluctuation, cause television set to generate splashette phenomenon.When back facet current is more than the maximum current of backlight lamp bar,
Backlight lamp bar can be made to damage, lead to television set blank screen.
Utility model content
Based on this, it is necessary to when there is the case where voltage falls suddenly for control optocoupler, will affect the work of control chip
Make relationship, causes back facet current to overshoot or fluctuate, television set is caused to generate splashette phenomenon.It is more than backlight lamp bar in back facet current
When maximum current, backlight lamp bar can be made to damage, lead to television set blank screen, a kind of backlight constant-current circuit is provided.
The utility model embodiment provides a kind of backlight constant-current circuit:
A kind of backlight constant-current circuit, applied to the backlight output circuit of television set, including current control module and voltage it is steady
Die block；
Current control module is used to connect the cathode of control optocoupler photophore, and for connecting the negative of backlight of television lamp bar
Pole is also used to access backlight adjustment signals；
Voltage Voltage stabilizing module is used to connect the anode of control optocoupler photophore, and the anode for connecting backlight lamp bar.
Above-mentioned backlight constant-current circuit, voltage of the voltage Voltage stabilizing module according to the anode of backlight lamp bar, stability contorting optocoupler hair
The cathode voltage of light device.Meanwhile the cathode of current control module connection backlight of television lamp bar, it can be according to stable control optocoupler
The cathode voltage and backlight adjustment signals of photophore control back facet current in a stable range, prevent back facet current
Situations such as appearance is overshooted or fluctuated, is effectively protected backlight lamp bar.
It in one of the embodiments, further include accessory power supply；
Accessory power supply is used to connect the anode of control optocoupler photophore.
Voltage Voltage stabilizing module includes voltage-stabiliser tube in one of the embodiments,；
Regulator tube negative is used to connect the anode of control optocoupler photophore, and the anode for connecting backlight lamp bar；
Voltage-stabiliser tube anode is for being grounded.
It in one of the embodiments, further include Linear processing module；
Voltage Voltage stabilizing module connects Linear processing module one end, Linear processing module other end connection control optocoupler photophore
Anode.
Linear processing module includes transistor in one of the embodiments,；
Transistor base and collector are used to connect the anode of backlight lamp bar；
Emitter is used to connect the anode of control optocoupler photophore.
Linear processing module further includes biasing resistor in one of the embodiments,；
The base stage of transistor connects the collector of transistor by biasing resistor.
It in one of the embodiments, further include the first division module and the second division module；
Regulator tube negative connects the anode of backlight lamp bar by the first division module；
Regulator tube negative is grounded by the second division module.
Current control module includes integrating circuit in one of the embodiments,；
The first input end of integrating circuit is for accessing backlight adjustment signals；
Second input terminal of integrating circuit is used to connect the cathode of backlight of television lamp bar；
The output end of integrating circuit is used to connect the cathode of control optocoupler photophore.
Integrating circuit includes operational amplifier, integrating resistor and integrating capacitor in one of the embodiments,；
The non-inverting input terminal of operational amplifier is the first input end of integrating circuit；
The inverting input terminal of operational amplifier is used to connect the cathode of backlight of television lamp bar by integrating resistor；
The inverting input terminal of operational amplifier connects the output end of operational amplifier by integrating capacitor；
The output end of operational amplifier is the output end of integrating circuit.
It in one of the embodiments, further include anti-jamming circuit；
The first input end of integrating circuit is used to access backlight adjustment signals by anti-jamming circuit.
Detailed description of the invention
Fig. 1 is backlight constant-current circuit function structure chart；
Fig. 2 is the integrating circuit figure of an embodiment；
Fig. 3 is the backlight constant-current circuit function structure chart of an embodiment；
Fig. 4 is the voltage Voltage stabilizing module circuit diagram of an embodiment.
Specific embodiment
The purpose of this utility model, technical solution and technical effect in order to better understand, below in conjunction with attached drawing and reality
It applies example and further explaining illustration is carried out to the utility model.It states simultaneously, embodiments described below is only used for explaining this
Utility model is not used to limit the utility model.
The utility model embodiment provides a kind of backlight constant-current circuit:
Fig. 1 is backlight constant-current circuit function structure chart, as shown in Figure 1, backlight constant-current circuit includes current control module 100
With voltage Voltage stabilizing module 101；
Current control module 100 is used to connect the cathode of control optocoupler photophore, and for connecting backlight of television lamp bar
Cathode, be also used to access backlight adjustment signals；
Wherein, current control module 100 is used for cathode voltage and backlight adjustment signals according to control optocoupler photophore, leads to
The cathode for crossing backlight of television lamp bar carries out back facet current control to backlight lamp bar.
Current control module 100 includes integrating circuit in one of the embodiments,；
The first input end of integrating circuit is for accessing backlight adjustment signals；
Second input terminal of integrating circuit is used to connect the cathode of backlight of television lamp bar；
The output end of integrating circuit is used to connect the cathode of control optocoupler photophore.
By integrating circuit, the cathode voltage of the control optocoupler photophore of access is passed through into integrating circuit and control optocoupler hair
The cathode of light device, backlight adjustment signals are handled, to control back facet current.
Fig. 2 is the integrating circuit figure of an embodiment, as shown in Fig. 2, integrating circuit includes operational amplifier U1, integral
Resistance R1 and integrating capacitor C1；
The non-inverting input terminal of operational amplifier U1 is the first input end of integrating circuit；
The inverting input terminal of operational amplifier U1 is used for the cathode by integrating resistor R1 connection backlight of television lamp bar；
The inverting input terminal of operational amplifier U1 passes through the output end of integrating capacitor C1 connection operational amplifier U1；
The output end of operational amplifier U1 is the output end of integrating circuit.
Wherein, integrating resistor R1 and integrating capacitor C1 is used for integral compensation, and associative operation amplifier U1 constitutes integrating circuit,
Back facet current is controlled.
It in one of the embodiments, further include anti-jamming circuit；
The first input end of integrating circuit is used to access backlight adjustment signals by anti-jamming circuit.
Wherein, the clutter of backlight adjustment signals is filtered out by anti-jamming circuit, improves the stability of back facet current control.
In one of the embodiments, as shown in Fig. 2, anti-jamming circuit includes the first filter resistance R2, the second filtered electrical
Hinder R3 and filter capacitor C2；
For accessing backlight adjustment signals, the other end is respectively used to through the second filter resistance for first one end filter resistance R2
R3 and filter capacitor are grounded C2.
RC filter circuit is constituted by the first filter resistance R2, the second filter resistance R3 and filter capacitor C2, filters out backlight
The clutter of adjustment signal.
Fig. 3 is the backlight constant-current circuit function structure chart of an embodiment, as shown in figure 3, backlight constant-current circuit further includes
Accessory power supply 200；
Accessory power supply 200 is used to connect the anode of control optocoupler photophore.
Wherein, accessory power supply 200 is provided by the connection of the anode with control optocoupler photophore for control optocoupler photophore
Supply voltage.
Voltage Voltage stabilizing module 101 is used to connect the anode of control optocoupler photophore, and the anode for connecting backlight lamp bar.
Wherein, voltage Voltage stabilizing module 101 is by the positive connection with backlight lamp bar, according to the electricity of the anode of backlight lamp bar
It presses to control the anode of optocoupler photophore and providing stable voltage, is carried out at pressure stabilizing with the cathode voltage to control optocoupler photophore
Reason.
Voltage Voltage stabilizing module 101 is control optocoupler according to the voltage of the anode of backlight lamp bar in one of the embodiments,
Voltage swing provided by the anode of photophore is identical as the supply voltage size that accessory power supply 200 provides.
Fig. 4 is the voltage Voltage stabilizing module circuit diagram of an embodiment, as shown in figure 4, voltage Voltage stabilizing module 101 includes steady
Pressure pipe D1；
Voltage-stabiliser tube D1 cathode is used to connect the anode of control optocoupler photophore, and the anode for connecting backlight lamp bar；
Voltage-stabiliser tube D1 anode is for being grounded.
Wherein, voltage-stabiliser tube D1 carries out pressure stabilizing according to the anode of backlight lamp bar, is greater than one in the cathode voltage of backlight lamp bar
When preset value, the anode to control optocoupler photophore is provided to the burning voltage for being equal to preset value.
Voltage-stabiliser tube D1 is to provide the voltage-stabiliser tube of 12V burning voltage in one of the embodiments,.
Liquid crystal display panel further includes Linear processing module 300 in one of the embodiments,；
Voltage Voltage stabilizing module 101 connects 300 one end of Linear processing module, the connection control of 300 other end of Linear processing module
The anode of optocoupler photophore.
Wherein, Linear processing module 300 makes the voltage of one end being connected by the connection with voltage Voltage stabilizing module 101
Tend to be linear, voltage Voltage stabilizing module 101 is made to tend to linear voltage stabilization.
In one of the embodiments, as shown in figure 4, Linear processing module 300 includes transistor Q1；
Transistor Q1 base stage and collector are used to connect the anode of backlight lamp bar；
Transistor Q1 emitter is used to connect the anode of control optocoupler photophore.
In one of the embodiments, as shown in figure 4, Linear processing module 300 further includes biasing resistor Rp；
The base stage of transistor Q1 passes through the collector of biasing resistor Rp connection transistor Q1.
Wherein, bias voltage is provided for the base stage of transistor Q1 and the inter-collector of transistor Q1 by biasing resistor Rp,
Improve the job stability of transistor Q1.
It in one of the embodiments, further include the first division module and the second division module；
Voltage-stabiliser tube D1 cathode connects the anode of backlight lamp bar by the first division module；
Voltage-stabiliser tube D2 cathode is grounded by the second division module.
Voltage-stabiliser tube D1 cathode voltage is adjusted by the first division module and the second division module, that is, is adjusted to control optocoupler hair
The cathode voltage of light device.
In one of the embodiments, as shown in figure 4, the first division module includes the first divider resistance Rf1, the second partial pressure
Module includes the first divider resistance Rf2.
Above-mentioned backlight constant-current circuit, voltage of the voltage Voltage stabilizing module 101 according to the anode of backlight lamp bar, stability contorting optocoupler
The cathode voltage of photophore.Meanwhile current control module 100 connects the cathode of backlight of television lamp bar, it can be according to stable control
The cathode voltage and backlight adjustment signals of optocoupler photophore processed control back facet current in a stable range, prevent from carrying on the back
There is situations such as overshooting or fluctuating in photoelectric current, and is effectively protected backlight lamp bar.
Each technical characteristic of above embodiments can be combined arbitrarily, for simplicity of description, not to above-described embodiment
In each technical characteristic it is all possible combination be all described, as long as however, the combination of these technical characteristics be not present lance
Shield all should be considered as described in this specification.
Above embodiments only express the several embodiments of the utility model, and the description thereof is more specific and detailed, but simultaneously
The limitation to utility model patent range therefore cannot be interpreted as.It should be pointed out that for the ordinary skill people of this field
For member, without departing from the concept of the premise utility, various modifications and improvements can be made, these belong to this reality
With novel protection scope.Therefore, the scope of protection shall be subject to the appended claims for the utility model patent.
Claims (10)
1. a kind of backlight constant-current circuit, the backlight output circuit applied to television set, which is characterized in that including current control module
With voltage Voltage stabilizing module；
The current control module is used to connect the cathode of control optocoupler photophore, and for connecting the negative of backlight of television lamp bar
Pole is also used to access backlight adjustment signals；
The voltage Voltage stabilizing module is used to connect the anode of the control optocoupler photophore, and for connecting the backlight lamp bar
Anode.
2. backlight constant-current circuit according to claim 1, which is characterized in that further include accessory power supply；
The accessory power supply is used to connect the anode of the control optocoupler photophore.
3. backlight constant-current circuit according to claim 1, which is characterized in that the voltage Voltage stabilizing module includes voltage-stabiliser tube；
The regulator tube negative is used to connect the anode of the control optocoupler photophore, and for connecting the backlight lamp bar just
Pole；
The voltage-stabiliser tube anode is for being grounded.
4. backlight constant-current circuit according to claim 1, which is characterized in that further include Linear processing module；
The voltage Voltage stabilizing module connects described Linear processing module one end, and the Linear processing module other end connects the control
The anode of optocoupler photophore processed.
5. backlight constant-current circuit according to claim 4, which is characterized in that the Linear processing module includes transistor；
The transistor base and collector are used to connect the anode of the backlight lamp bar；
The emitter is used to connect the anode of the control optocoupler photophore.
6. backlight constant-current circuit according to claim 5, which is characterized in that the Linear processing module further includes biased electrical
Resistance；
The base stage of the transistor connects the collector of the transistor by the biasing resistor.
7. backlight constant-current circuit according to claim 3, which is characterized in that further include the first division module and the second partial pressure
Module；
The regulator tube negative connects the anode of the backlight lamp bar by first division module；
The regulator tube negative is grounded by second division module.
8. backlight constant-current circuit according to claim 1, which is characterized in that the current control module includes integral electricity
Road；
The first input end of the integrating circuit is for accessing the backlight adjustment signals；
Second input terminal of the integrating circuit is used to connect the cathode of the backlight of television lamp bar；
The output end of the integrating circuit is used to connect the cathode of the control optocoupler photophore.
9. backlight constant-current circuit according to claim 8, which is characterized in that the integrating circuit include operational amplifier,
Integrating resistor and integrating capacitor；
The non-inverting input terminal of the operational amplifier is the first input end of the integrating circuit；
The inverting input terminal of the operational amplifier is used to connect the negative of the backlight of television lamp bar by the integrating resistor
Pole；
The inverting input terminal of the operational amplifier connects the output end of the operational amplifier by the integrating capacitor；
The output end of the operational amplifier is the output end of the integrating circuit.
10. backlight constant-current circuit according to claim 8, which is characterized in that current control module further includes anti-interference electricity
Road；
The first input end of the integrating circuit is used to access the backlight adjustment signals by the anti-jamming circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920229807.0U CN209402627U (en) | 2019-02-21 | 2019-02-21 | Backlight constant-current circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920229807.0U CN209402627U (en) | 2019-02-21 | 2019-02-21 | Backlight constant-current circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209402627U true CN209402627U (en) | 2019-09-17 |
Family
ID=67899393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920229807.0U Active CN209402627U (en) | 2019-02-21 | 2019-02-21 | Backlight constant-current circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209402627U (en) |
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2019
- 2019-02-21 CN CN201920229807.0U patent/CN209402627U/en active Active
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