CN2938640Y - DC power supply conversion circuit and TV. and with multifunction function - Google Patents
DC power supply conversion circuit and TV. and with multifunction function Download PDFInfo
- Publication number
- CN2938640Y CN2938640Y CN 200620088444 CN200620088444U CN2938640Y CN 2938640 Y CN2938640 Y CN 2938640Y CN 200620088444 CN200620088444 CN 200620088444 CN 200620088444 U CN200620088444 U CN 200620088444U CN 2938640 Y CN2938640 Y CN 2938640Y
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- power supply
- power
- supply input
- output end
- negative pole
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- Dc-Dc Converters (AREA)
Abstract
The utility model discloses a DC power supply changeover circuit with multiple protection functions and a television set, comprising a DC power supply input terminal, a DC-DC conversion power board and a DC power output terminal. A transient voltage inhibitor is connected between the positive and negative poles of the DC power supply input terminal and those of the DC power output terminal to realize the inhibitory action of the power supply changeover circuit against the transient voltage. By connecting a Schottky diode in series between the negative pole of the DC power supply input terminal and the ground of the DC-DC conversion power board, the damage caused by reversal of the power input to the television set is avoided. A fuse is connected to the positive pole of the DC power supply input terminal is connected in series to realize the over-current protection of the circuit. The power supply changeover circuit of the utility model uses an LM2678T-ADJDC power supply conversion chip for conversion between DC voltages and is characterized by simple circuit structure, high reliability, and can be easily built into the enclosure of the car-borne television set.
Description
Technical field
The utility model belongs to the direct-current power supply converting circuit technical field, specifically, relates to a kind of direct-current power supply converting circuit that input overcurrent protection function, transient voltage protection function and input power supply connect anti-defencive function that has.
Background technology
At present, need the electric equipment of direct current supply more and more,, therefore, need the DC-DC change-over circuit to satisfy the power demands of distinct device because the needed direct voltage of machine intimate has nothing in common with each other.With regard to by the in-car TV that is applied on train or the automobile, because for the external power source of in-car TV power supply is generally direct current+24V (permissible variation is ± 10%), and the inner required voltage of TV is direct current+12V (permissible variation is ± 10%), so, must with input+the 12V direct voltage is depressured to+12V by the DC-DC change-over circuit.Because in-car TV is relatively complicated when mounted, the operator makes a fault in installation process easily, if lack necessary protective circuit in the DC-DC change-over circuit, is easy to cause the damage of in-car TV.For some direct-current power supply converting circuits that generally adopt at present, its protective circuit structure relative complex is not suitable for being applied in the less in-car TV of circuit board space.
Summary of the invention
The problem that the utility model easily causes in-car TV to damage for the direct-current power supply converting circuit that solves in-car TV in the prior art owing to lack effective protective circuit; a kind of novel direct-current power supply converting circuit with kinds of protect function is provided; its circuit structure is simple; defencive function is complete, is suitable for promoting the use of in the less in-car TV of circuit board space.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of direct-current power supply converting circuit and television set with kinds of protect function; comprise dc supply input, DC-DC conversion electric power plate and dc power output end, be connected with a transient voltage inhibitor respectively between the positive pole of described dc supply input and the negative pole and between the positive pole of dc power output end and the negative pole.
Described transient voltage suppressor is a TVS diode, its negative electrode connects the positive pole of described dc supply input or dc power output end, anode connects the negative pole of described dc supply input or dc power output end, to realize the inhibitory action of power-switching circuit to transient voltage.
Positive pole and negative pole for fear of the power supply input connect the damage that causes television set on the contrary, between the ground of the negative pole of described dc supply input and DC-DC conversion electric power plate, be in series with Schottky diode, the anode of described diode connects the ground of DC-DC conversion electric power plate, and negative electrode connects the negative pole of dc supply input.
Big for fear of single Schottky diode caloric value, the problem of job insecurity, be parallel with at least at the two ends of described Schottky diode one with its Schottky diode in the same way.
In order to simplify the structure of direct-current power supply converting circuit, on described DC-DC conversion electric power plate,, a direct current power conversion chip realizes conversion between the direct voltage by being set.Can the better protection its internal circuit when over current fault such as short circuit occurring at television set, the positive pole of described dc supply input connects the input of described DC power supply conversion chip through the fuse of series connection, to realize overcurrent protection function.The output of described DC power supply conversion chip is pressed with the output galvanic current through the positive pole that the inductance and the filter capacitor of ground connection of series connection is connected described dc power output end.The negative pole of described dc power output end and the earth terminal of DC power supply conversion chip all are connected the ground of power panel.
Compared with prior art; advantage of the present utility model and good effect are: the utility model is finished conversion between the direct voltage by adopting LM2678T-ADJ DC power supply conversion chip; have significant advantages such as circuit structure is simple, reliability height; and taken into full account the variety of issue that in-car TV occurs easily in installing and using process; on the power-switching circuit plate, design power supply and connect anti-protective circuit, transient voltage protection circuit and current foldback circuit, effectively improved the fail safe that in-car TV is installed and used.Power source conversion plate bulk of the present utility model is little, in light weight, is easy to be built in the cabinet of in-car TV, and the protective circuit of multiple practicality also provides necessary guarantee for television set complete machine and train, the safe and reliable work of automobile power source.
Description of drawings
Fig. 1 is the direct-current power supply converting circuit schematic diagram that the utlity model has the kinds of protect function.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done explanation in further detail.
The utility model is that the high efficiency dc-to-dc power conversion chip 801 of LM2678T-ADJ is finished the conversion between the direct voltage by adopting a model, referring to shown in Figure 1.Described DC-DC power conversion chip 801 input voltage ranges are between 8 to 40V, and electric current is 5A, and switching frequency is fixed, be used for in-car TV can with input+the 24V DC power supply converts to+the 12V DC power supply, for a back level master control borad circuit provides direct current supply.
Outside+24V DC power supply inserts the power source conversion plate by input XP803; the input PIN2 that connects power conversion chip 801 through the fuse F802 of series connection; utilize the characteristic of fuse overcurrent fusing; make late-class circuit open a way when short trouble causes overcurrent occurring, thereby cut-out+24V input power supply is with the protection TV set circuit.Be connected the input PIN2 of power conversion chip 801 and shunt capacitance C802, C804～C806 between the ground to input+the 24V power supply plays voltage stabilizing, filter action.After the output PIN1 output conversion of power conversion chip 801+the 12V direct voltage, after voltage stabilizing didoe VD803, inductance L 801 and filter capacitor C803, C807 carry out the voltage stabilizing processing, by the stable+12V direct voltage of dc power output end XP802 output.
Static discharge ESD and generator, motor, relay, switched inductors loads such as transformer all can produce transient voltage, for fear of or reduce the damage of transient voltage to the complete machine components and parts, cause the problem of television set cisco unity malfunction, be connected with a transient voltage inhibitor respectively between the positive pole of power input XP803 and the negative pole and between the positive pole of power output end XP802 and negative pole, with TVS diode VD801, VD802 is an example, adopting model respectively is the avalanche silicon diode realization of SA24CA and SA12CA, its negative electrode connects the positive pole of power input XP803 or power output end XP802, anode connects the negative pole of power input XP803 or power output end XP802, and power can reach 500 watts.
The positive pole of power supply input and negative pole connect when in-car TV is installed for fear of the operator and to cause machine to burn on the contrary; bring problems such as loss to the user, in DC converting circuit of the present utility model, designed by what Schottky diode VD804, VD805 formed and connect anti-protective circuit.Utilize the unidirectional on state characteristic and the little characteristics of forward conduction voltage drop of Schottky diode, Schottky diode VD805 connects between the ground of the ground of+24V input power supply and conversion electric power plate.Big for fear of single Schottky diode caloric value, finish the function of a Schottky diode with two same Schottky diode parallel connections.The ground of the negative electrode connection+24V input power supply of described Schottky diode VD804, VD805, anode connects the ground of conversion electric power plate.When power supply is correctly connected, Schottky diode VD804, VD805 normally, power work; Connect inverse time at power supply, Schottky diode VD804, VD805 oppositely end, and do not have electric current to flow through, and power supply is not worked, thereby have realized the anti-protection of connecing of power input voltage.
The utility model has been realized effective conversion between the DC power supply by adopting above-mentioned simple circuit configuration, and has multiple protection functions, for the operate as normal of television set complete machine provides reliable guarantee.Certainly; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example, and variation, remodeling, interpolation or replacement that those skilled in the art are made in essential scope of the present utility model also should belong to protection range of the present utility model.
Claims (10)
1. direct-current power supply converting circuit with kinds of protect function; comprise dc supply input, DC-DC conversion electric power plate and dc power output end, it is characterized in that: be connected with a transient voltage inhibitor respectively between the positive pole of described dc supply input and the negative pole and between the positive pole of dc power output end and the negative pole.
2. the direct-current power supply converting circuit with kinds of protect function according to claim 1; it is characterized in that: described transient voltage suppressor is a TVS diode; its negative electrode connects the positive pole of described dc supply input or dc power output end, and anode connects the negative pole of described dc supply input or dc power output end.
3. the direct-current power supply converting circuit with kinds of protect function according to claim 1; it is characterized in that: between the ground of the negative pole of described dc supply input and DC-DC conversion electric power plate, be in series with Schottky diode; the anode of described diode connects the ground of DC-DC conversion electric power plate, and negative electrode connects the negative pole of dc supply input.
4. the direct-current power supply converting circuit with kinds of protect function according to claim 3 is characterized in that: be parallel with at least at the two ends of described Schottky diode one with its Schottky diode in the same way.
5. according to claim 1 or 3 described direct-current power supply converting circuits with kinds of protect function, it is characterized in that: described DC-DC conversion electric power plate is provided with a direct current power conversion chip, the positive pole of dc supply input connects the input of described DC power supply conversion chip through the fuse of series connection, and its output is connected the positive pole of described dc power output end through the filter capacitor of the inductance of series connection and ground connection; The negative pole of described dc power output end and the earth terminal of DC power supply conversion chip all are connected the ground of power panel.
6. one kind has the described television set with direct-current power supply converting circuit of kinds of protect function of claim 1; comprise dc supply input, DC-DC conversion electric power plate and dc power output end, it is characterized in that: be connected with a transient voltage inhibitor respectively between the positive pole of described dc supply input and the negative pole and between the positive pole of dc power output end and the negative pole.
7. television set according to claim 6, it is characterized in that: described transient voltage suppressor is a TVS diode, its negative electrode connects the positive pole of described dc supply input or dc power output end, and anode connects the negative pole of described dc supply input or dc power output end.
8. television set according to claim 6, it is characterized in that: between the ground of the negative pole of described dc supply input and DC-DC conversion electric power plate, be in series with Schottky diode, the anode of described diode connects the ground of DC-DC conversion electric power plate, and negative electrode connects the negative pole of dc supply input.
9. television set according to claim 8 is characterized in that: be parallel with at least at the two ends of described Schottky diode one with its Schottky diode in the same way.
10. according to claim 6 or 8 described television sets, it is characterized in that: described DC-DC conversion electric power plate is provided with a direct current power conversion chip, the positive pole of dc supply input connects the input of described DC power supply conversion chip through the fuse of series connection, and its output is connected the positive pole of described dc power output end through the filter capacitor of the inductance of series connection and ground connection; The negative pole of described dc power output end and the earth terminal of DC power supply conversion chip all are connected the ground of power panel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620088444 CN2938640Y (en) | 2006-08-23 | 2006-08-23 | DC power supply conversion circuit and TV. and with multifunction function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620088444 CN2938640Y (en) | 2006-08-23 | 2006-08-23 | DC power supply conversion circuit and TV. and with multifunction function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2938640Y true CN2938640Y (en) | 2007-08-22 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620088444 Expired - Fee Related CN2938640Y (en) | 2006-08-23 | 2006-08-23 | DC power supply conversion circuit and TV. and with multifunction function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2938640Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102723858A (en) * | 2012-07-04 | 2012-10-10 | 铭薪电子（深圳）有限公司 | Car-mounted wide power supply voltage stabilization plate and navigation television |
| CN108683239A (en) * | 2018-08-04 | 2018-10-19 | 东莞市三敏电子科技有限公司 | A kind of USB charging circuits of electric intelligent household |
| CN112688292A (en) * | 2020-12-28 | 2021-04-20 | 深圳市安帕尔科技有限公司 | Prevent that DC power connects circuit of reversal among gaseous check out test set |
-
2006
- 2006-08-23 CN CN 200620088444 patent/CN2938640Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102723858A (en) * | 2012-07-04 | 2012-10-10 | 铭薪电子（深圳）有限公司 | Car-mounted wide power supply voltage stabilization plate and navigation television |
| CN102723858B (en) * | 2012-07-04 | 2015-04-08 | 铭薪电子（深圳）有限公司 | Car-mounted wide power supply voltage stabilization plate and navigation television |
| CN108683239A (en) * | 2018-08-04 | 2018-10-19 | 东莞市三敏电子科技有限公司 | A kind of USB charging circuits of electric intelligent household |
| CN108683239B (en) * | 2018-08-04 | 2024-02-23 | 东莞市三敏电子科技有限公司 | USB charging circuit of electric intelligent home |
| CN112688292A (en) * | 2020-12-28 | 2021-04-20 | 深圳市安帕尔科技有限公司 | Prevent that DC power connects circuit of reversal among gaseous check out test set |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20070822 Termination date: 20110823 |