CN1713474A - Overload protecting circuit of transformer - Google Patents
Overload protecting circuit of transformer Download PDFInfo
- Publication number
- CN1713474A CN1713474A CN 200410025365 CN200410025365A CN1713474A CN 1713474 A CN1713474 A CN 1713474A CN 200410025365 CN200410025365 CN 200410025365 CN 200410025365 A CN200410025365 A CN 200410025365A CN 1713474 A CN1713474 A CN 1713474A
- Authority
- CN
- China
- Prior art keywords
- voltage
- transformer
- output
- loop
- abnormal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention consists of: switching power outputting the AC power to voltage generating device through width pulse modulation; feedback control unit outputting feedback signal to switching power; voltage detecting unit selecting standard input voltage from voltage outputted from voltage generating device and controlling feedback control unit according to control signal outputted from standard voltage; abnormal voltage detecting unit connecting to all outputs of voltage generating device in order to monitor abnormal voltage generated from each output contact, when abnormal voltage occurs, cut off control signal to feedback control unit outputted from voltage detecting unit.
Description
(1) technical field
The invention relates to transformer overload protection loop; , refer in particular to the supervision of utilization to the many terminals short phenomenons of 2 sides of transformer, prevent overladen generation, thus a kind of transformer overload protection loop of protection transformer.
(2) background technology
All can application class in all electronics, the communication equipment like the supply unit of Switching Power Supply SMPS (Switch Mode PowerSupple).This supply unit produces direct current (DC) power supply of the inner required all size of product.So supply unit needs the input of external ac power source, and utilize equipment such as transformer that the DC power supply of required all size is provided to product.
1 side input voltage of above-mentioned transformer adopting, 2 sides produce the structure of variety classes voltages, so product is inner when needing various voltage, and the control by 2 side number of turns ratios of transformer and 2 different terminals of side produce the voltage of required size.
This Switching Power Supply that has transformer is necessary to take safeguard measure, prevents the superpotential generation of transformer.If 2 sides of transformer produce overvoltage, the control loop from transformer acquisition dc voltage will be in overvoltage condition originally, and at this moment owing to too high voltage, control loop will make a mistake or cause the loop breakage.
Below be the detailed description in existing transformer overload protection loop, can be with reference to figure 1.
Existing overload protection loop is connected with voltage VDD input and pulse-width modulation control loop (the PWM control loop among the figure) 10 as shown in the figure among 1 lateral coil 50a of transformer 50.Above-mentioned pulse-width modulation control loop 10 is by the control to pulse-width modulation (PWM:Pulse Width Modulation), and alternative supply is to the voltage of 1 lateral coil 50a of transformer 501.
2 lateral coils of above-mentioned transformer 50 are made of two coil 50b, 50c.These two 2 lateral coil 50b, 50c are by the voltages of the different number of turns than the different sizes of generation.Each side of 2 lateral coil 50b, 50c is connected with diode D1, D2 and capacitor C1, C2 respectively.The opposite side of above-mentioned 2 lateral coil 50b, 50c and capacitor C1, the opposite side of C2 all is connected on the grounding apparatus.Above-mentioned diode D1, D2 plays the effect of rectification, and capacitor C1, C2 then adjusts the supply of stable dc voltage.Like this, 2 times lateral coil 50b exports the 1st output voltage, and 2 lateral coil 50c of another one then export the 2nd output voltage.
In addition, in order to prevent the overload phenomenon of transformer 50, the output of 2 lateral coil 50b is connected with protection loop 30 by resistance R 1.Be provided with photoelectrical coupler 20 in the above-mentioned protection loop 30.Above-mentioned photoelectrical coupler 20 is by resistance R 1 picked up signal.
In the operation of photoelectrical coupler 20, thyristor SCR1 plays switch.That is, two resistance R 2 of resistance R 1 one ends series connection, R3, the tie point between these two resistance R 2, the R3 then is connected with gate terminal and the capacitor C4 of thyristor SCR1.In addition, the side terminal of an end of resistance R 3 and thyristor SCR1 links to each other with grounding apparatus; One side of capacitor C4 and photoelectrical coupler 20 is connected with the opposite side terminals of thyristor SCR1.
The signal that photoelectrical coupler 20 produces supplies in the pulse-width modulation control loop 10.
Existing transformer overload protection circuit's principle to said structure describes below.
By the control of 10 pairs of pulse-width modulations of pulse-width modulation control loop, 1 lateral coil 50a of transformer 50 obtains voltage and supplies with.Because 1 time lateral coil 50a produces induced voltage, 2 lateral coil 50b, 50c produces the voltage (the 1st output voltage, the 2nd output voltage) of different sizes, and the voltage of above-mentioned generation then supplies in the corresponding control loop (not shown) of product inside.
At this moment, the output voltage of 2 lateral coil 50b supplies to photoelectrical coupler 20 by resistance R 1.When thyristor SCR1 is in conducting (ON) state, photoelectrical coupler 20 will receive the voltage that obtains from resistance R 1, produce signal immediately.Thyristor SCR1 only receives by resistance R 2 at gate terminal, just starts working during voltage that R3 distributes.The signal that photoelectrical coupler 20 produces will be sent in the pulse-width modulation control loop 10; In case there is the signal of photoelectrical coupler 20 to pass to pulse-width modulation control loop 10, will be judged as normal condition, keep normal pulse width modulation controlled operating state afterwards.
But because the mistake that various electronic components take place in 2 sides of transformer 50, when making the tie point current potential of resistance R 1 be in zero potential, protection loop 30 will quit work.That is, the gate terminal of thyristor SCR1 can not get voltage, and thyristor SCR1 will be in not conducting (OFF) state, and therefore, photoelectrical coupler 20 can't form current path, just can't produce signal.
Pulse-width modulation control loop only when the signal of photoelectrical coupler 20 normally receives, is just started working, and just is not judged as abnormality if receive the signal of photoelectrical coupler 20, and the voltage that blocks 1 side of disconnected transformer 50 is supplied with.Suppress 2 superpotential generations of side of transformer 50 in this way, thereby prevent the damage of the control loop that causes because of overvoltage.
But there is following problem in existing transformer overload protection loop.
Existing transformer overload protection loop is to utilize the feedback of 2 side voltages of transformer to prevent overladen generation, but can't monitor the generation signal of 2 all terminals of side of transformer.That is because as shown in Figure 1, and in numerous voltages that 2 sides of transformer take place, equipment only feeds back the voltage that is decided to be standard to be controlled, so be difficult to accomplish to monitor all voltages that 2 sides of transformer produce comprehensively.Since the problems referred to above, the transformer overload phenomenon that produces in the instruments such as the very difficult inhibition in existing transformer overload protection loop audio devices.
(3) summary of the invention
The objective of the invention is in order to solve above-mentioned the problems of the prior art, propose a kind of transformer overload protection loop that can monitor all voltages of transformer and can suppress the overload generation.
Purpose of the present invention is achieved in that a kind of transformer overload protection loop, is the device for generating voltage that a kind of input that utilizes AC power can produce the required various direct voltages of product, it is characterized in that comprising:
Switching Power Supply alternately outputs to described device for generating voltage with described AC power through pwm switch;
The FEEDBACK CONTROL parts are to described Switching Power Supply output feedback signal;
The voltage detecting parts, choice criteria voltage is imported in the output voltage of described device for generating voltage, and controls the work of described FEEDBACK CONTROL parts according to described normal voltage output control signal;
The abnormal voltage detection part, be connected all outlet terminals of described device for generating voltage, monitor the generation of the many terminals abnormal voltages of output with this, when any outlet terminal produces when unusual, the disconnected control signal that outputs to described FEEDBACK CONTROL parts from described voltage detecting parts of card.
Effect of the present invention:
Aforesaid transformer overload protection of the present invention loop, can monitor the voltage of all generations of transformer that can produce all size voltage comprehensively, therefore, monitor and prevent overladen generation more exactly than existing transformer overload protection loop; In addition, the present invention needing to go for the audio devices and the video-unit of various voltage conditions; And, by application of the present invention, can ensure the supply of burning voltage, improved the reliability of product.
For further specifying above-mentioned purpose of the present invention, design feature and effect, the present invention is described in detail below with reference to accompanying drawing.
(4) description of drawings
Fig. 1 is a transformer overload protection loop diagram of using prior art;
Fig. 2 uses transformer overload protection circuit element figure of the present invention;
Fig. 3 uses the detailed pie graph in transformer overload protection of the present invention loop.
The symbol description of major part in the accompanying drawing:
101: Switching Power Supply (SMPS switch block) 103: FEEDBACK CONTROL parts
105: voltage detecting parts 107: the abnormal voltage detection part
T100: transformer
(5) embodiment
With reference to the accompanying drawings, describe the execution mode in transformer overload protection of the present invention loop in detail.
Fig. 2 is transformer overload protection circuit element figure of the present invention.
Transformer overload protection of the present invention loop is the device for generating voltage that a kind of input that utilizes AC power can produce the required various direct voltages of product.
As shown in the figure; transformer overload protection of the present invention loop; 1 side of its transformer T100 is connected with Switching Power Supply 101 (promptly; be the SMPS switch block 101 among Fig. 2); be that described AC power is alternately outputed to above-mentioned device for generating voltage through pwm switch; that is, the power supply of 1 lateral coil T101 of transformer T100 is supplied with by the switch alternation of Switching Power Supply 101.Switching Power Supply 101 is by the voltage of pulse width modulation controlled switch alternative supply to 1 lateral coil T101 of transformer T100.
From shown in Figure 2,2 ends of transformer T100 are made of 32 lateral coils.These 32 lateral coil T102, T103, T104 utilize the number of turns than producing different or identical voltage.That is, the side of 2 side the 1st coil T102 is connected the anode tap of diode D101; The cathode terminal of diode D101 then is connected with capacitor C101 one side power supply output C (the 1st voltage) outlet terminal.In addition, the side of 2 side the 2nd coil T103 links to each other with the anode tap of diode D103; The cathode terminal of diode D103 then is connected with power supply output B (the 2nd voltage) outlet terminal with capacitor C106 one end.The side of 2 side the 3rd coil T104 links to each other with the anode tap of diode D102; The cathode terminal of diode D102 then is connected with power supply output A (the 3rd voltage) outlet terminal with capacitor C103 one end.Also have, the other end of 2 side the 1st coil T102 and the 2nd coil T103, the 3rd coil T104 links to each other with grounding apparatus; Equally, three capacitor C101, C106, the other end of C103 also links to each other with grounding apparatus.Above-mentioned diode D101, D103, D122 play rectification; Above-mentioned capacitor C101, C106, C103 then can adjust the stable of direct current (DC) voltage supply.
The various voltages that produce at 2 sides of transformer T100 form and can suppress the protection loop that the transformer overload produces.
Above-mentioned protection loop is made of two parts; One is the voltage detecting parts 105 that produce normal voltage at 2 side voltages of transformer T100, and choice criteria voltage is imported (selecting the power supply of 2 lateral coil T102 of T100 to export A as the feedback power supply in the present embodiment) in the output voltage of described device for generating voltage; Another is FEEDBACK CONTROL parts 103, it is device to described Switching Power Supply 101 output feedback signals, it is according to the output voltage output of voltage detecting parts 105, specific aim provides the control signal of Switching Power Supply 101 actions, that is, voltage detecting parts 105 are controlled the work of described FEEDBACK CONTROL parts 103 according to the control signal of above-mentioned normal voltage output.In addition, also comprised the abnormal voltage detection part 107 that goes out abnormal voltage according to 2 side voltage detecting of transformer T100, abnormal voltage detection part 107, be connected all outlet terminals (2 lateral coil T101 of abnormal voltage detection part 107 and transformer T100 in the embodiment of Fig. 2 of described device for generating voltage, the output of T103 connects), monitor the generation of the many terminals abnormal voltages of output with this, when any outlet terminal produces when unusual, the disconnected control signal that outputs to described FEEDBACK CONTROL parts 103 from described voltage detecting parts 105 of card.
That is, FEEDBACK CONTROL parts 103 are according to voltage detecting parts 105 detected normal voltage output feedback signals; This feedback signal can be communicated to Switching Power Supply 100 and just illustrate that operating state is normal.But, anomaly appears in 2 side outputs that in a single day abnormal voltage detection part 107 detects transformer T100, voltage detecting parts 105 just can't output feedback signal, and then 103 of FEEDBACK CONTROL parts can't provide normal feedback signal to Switching Power Supply 100.
Shown in Figure 3 is the detailed loop diagram in transformer overload protection of the present invention loop.
Below with reference to Fig. 3, the detailed formation in protection of the present invention loop is described.
The abnormal voltage detection part 107 in protection loop is made of diode D107, and this diode D107 links to each other with 2 side voltage output ends of transformer T100.The anode tap of above-mentioned diode D107 is connected with tie point A100; Negative electrode then links to each other with 2 side voltage output ends of transformer T100.As shown in Figure 3,2 of transformer T100 sides have only two outputs; Wherein must there be the output voltage of 2 side voltage output ends to be applied to normal voltage, so as long as the another one voltage output end is carried out the supervision (end of diode D107 is connected with the output of 2 lateral coil T101 of transformer T100 in the present embodiment) of abnormal voltage.When 2 sides of transformer T100 had three voltage output ends, 107 of above-mentioned abnormal voltage detection parts were made of the diode that is connected to two off-standard voltage outputs but as shown in Figure 2.
Above-mentioned voltage detecting parts 105 link to each other with 2 side normal voltage outputs of transformer T100 (linking to each other with 2 lateral coil T102 of transformer T100 in Fig. 3 embodiment) by two resistance R 103, the R104 of series connection.In addition, two resistance R 103 have tie point A100 between the R104; This tie point A100 links to each other with the gate terminal of thyristor (SCR) element IC102.The end of above-mentioned thyristor element IC102 is connected with grounding apparatus, and another section then links to each other with photoelectrical coupler IC101.
Include photoelectrical coupler IC101 in the FEEDBACK CONTROL parts 103, its effect is that feedback signal is communicated to Switching Power Supply 100.The light-emitting component of above-mentioned photoelectrical coupler IC101 is connected between resistance R 101 and the thyristor element IC102.The photo detector of photoelectrical coupler IC101 is connected between Switching Power Supply 100 and the earthing device in addition.Connect resistance R 102 on the tie point between resistance R 101 and the light-emitting component again; And the other end of resistance R 102 then is connected on the tie point between light-emitting component and the thyristor element IC102.An end that connects capacitor C105 on the above-mentioned tie point; The other end of capacitor C105 then links to each other with tie point A100.
Loop shown in the figure can only monitor a transformer voltage, and suppress overladen generation.But the transformer overload protection loop among the present invention is not subjected to this restriction.If the SMPS supply unit has 2 transformers, and 2 side voltages of each transformer produce to be held when all being 6,6 diodes (as the diode D107 among Fig. 3) are set on the abnormal voltage detection part, just can monitor 2 times of two transformers voltage that side produced simultaneously.
In addition, the inductor L102 and capacitor C102, the C104 that in Fig. 3, comprise 2 sides that are connected transformer T100.
Below above-mentioned transformer overload protection circuit's principle is described.
The power supply of 1 lateral coil T101 of transformer T100 is supplied with the control of the pulse-width modulation that is subjected to Switching Power Supply 100.Then according to resulting from lateral coil T101 induced voltage 1 time, at the voltage (be respectively 3.3v in the present embodiment, reach 5.3v) of 2 lateral coil T102, T104 generation different sizes.The voltage of above-mentioned generation is fed in the corresponding control loop of product inside.
At this moment transformer T100 the output voltage of 2 lateral coil T104 pass on to photoelectrical coupler IC101 by resistance R 101.
On the other hand, 2 of above-mentioned transformer lateral coil T104 output voltages will be charged to inductor L102 and capacitor C104; Output voltage after the R104 dividing potential drop, is communicated to the gate terminal of thyristor element IC102 by resistance R 103.Till signal is communicated to gate terminal, thyristor element IC102 will keep on-state.Therefore, by resistance R 103, institute's sizing of R104 dividing potential drop (about 2.5 volts) voltage is used as connecting the voltage of thyristor element IC102.
Because such controlled condition, when thyristor element IC102 was in conducting (ON) state, photoelectrical coupler IC101 started working under the effect of voltage, and produced signal.The signal that photoelectrical coupler IC101 produces is communicated to Switching Power Supply 100; Once receive signal from photoelectrical coupler IC101, the voltage that transformer T100 is produced is judged as normal condition, and keeps normal pulse width modulation controlled operating state when Switching Power Supply 100.
In addition, when 2 side operate as normal of transformer T100, affact on the diode D107 of abnormal voltage detection part 107 and will produce back voltage, so diode D107 is in off position.
But when be short-circuited phenomenon or when abnormality takes place of the capacitor C102 that is connected T1002 lateral coil T102 of transformer, 3.3 volts of output lines are output voltage normally, thereby the cathode terminal voltage of diode D107 becomes 0 volt.In other words, the cathode terminal of diode D107 will be in ground state.At this moment, the anode tap of diode D107 will be in conducting state under the effect of tie point A100 voltage.
For above-mentioned reasons, the voltage of thyristor element IC102 gate terminal can't reach work required decide 2.5 volts of voltages, thereby thyristor element IC102 will be in closed condition.Meanwhile, photoelectrical coupler IC101 can't form current path, therefore can't produce feedback signal.
Originally be set at the Switching Power Supply 100 of when the generation signal of photoelectrical coupler IC101 is normally imported, just starting working, if can't receive signal from photoelectrical coupler IC101, to be judged as abnormal condition automatically, and the service voltage of disconnected T1001 the side of transformer of card.Thereby suppress the superpotential generation of T1002 side of transformer, and prevent the damage of the control loop that overvoltage causes.
In sum, characteristics of the present invention are exactly the voltage that can monitor the generation of 2 side institutes of transformer live end, and prevent the superpotential generation of any output of 2 sides of transformer.In order to reach this purpose, be equipped with the abnormal voltage detection part that can monitor all 2 side output end voltages of transformer among the present invention.When generation is unusual, the abnormal voltage detection part will block the disconnected gate voltage that is used for the control voltage thyristor element of tranformer protection loop works.
In addition, the overload protection loop among the present invention is not limited in the supervision of transformer generation voltage; It also can be applied in other supply units, can monitor the voltage of the element output that produces the required institute of product sizing direct voltage, and suppresses the generation of abnormal voltage.
Though the present invention describes with reference to current specific embodiment, but those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the present invention, should understand and wherein can make variations and modifications and do not break away from the present invention in a broad sense, so be not as limitation of the invention, as long as in connotation scope of the present invention, all will drop in the scope of application for patent of the present invention variation, the distortion of the above embodiment.
Claims (3)
1, a kind of transformer overload protection loop is the device for generating voltage that a kind of input that utilizes AC power can produce the required various direct voltages of product, it is characterized in that comprising:
Switching Power Supply alternately outputs to described device for generating voltage with described AC power through pwm switch;
The FEEDBACK CONTROL parts are to described Switching Power Supply output feedback signal;
The voltage detecting parts, choice criteria voltage is imported in the output voltage of described device for generating voltage, and controls the work of described FEEDBACK CONTROL parts according to described normal voltage output control signal;
The abnormal voltage detection part, be connected all outlet terminals of described device for generating voltage, monitor the generation of the many terminals abnormal voltages of output with this, when any outlet terminal produces when unusual, the disconnected control signal that outputs to described FEEDBACK CONTROL parts from described voltage detecting parts of card.
2, transformer overload protection as claimed in claim 1 loop is characterized in that:
Described FEEDBACK CONTROL parts have comprised the photoelectrical coupler of output feedback signal and the thyristor element of control photoelectrical coupler current path, during described device for generating voltage generation overload, be voltage by the disconnected described thyristor element gate terminal of described abnormal voltage detection part card.
3, transformer overload protection as claimed in claim 2 loop is characterized in that:
Described abnormal voltage detection part is to adopt diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410025365 CN1713474A (en) | 2004-06-23 | 2004-06-23 | Overload protecting circuit of transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410025365 CN1713474A (en) | 2004-06-23 | 2004-06-23 | Overload protecting circuit of transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1713474A true CN1713474A (en) | 2005-12-28 |
Family
ID=35718967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410025365 Pending CN1713474A (en) | 2004-06-23 | 2004-06-23 | Overload protecting circuit of transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1713474A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101924348B (en) * | 2010-02-05 | 2012-06-27 | 保定天威集团有限公司 | Control method for judging overload of converter transformer |
| CN102047521B (en) * | 2008-05-29 | 2014-03-26 | Abb研究有限公司 | Protection system for voltage transformers |
| CN110118907A (en) * | 2019-05-30 | 2019-08-13 | 裕文新兴电子(深圳)有限公司 | Transformer synthesis detection device |
-
2004
- 2004-06-23 CN CN 200410025365 patent/CN1713474A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102047521B (en) * | 2008-05-29 | 2014-03-26 | Abb研究有限公司 | Protection system for voltage transformers |
| CN101924348B (en) * | 2010-02-05 | 2012-06-27 | 保定天威集团有限公司 | Control method for judging overload of converter transformer |
| CN110118907A (en) * | 2019-05-30 | 2019-08-13 | 裕文新兴电子(深圳)有限公司 | Transformer synthesis detection device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5944099B2 (en) | Voltage limiting and reverse polarity series connection type LED device | |
| CN2710244Y (en) | Voltage-stabilizing switch power supply with over voltage output protective circuit and electronic equipment | |
| US9504121B2 (en) | System and method for providing surge protection for an AC direct step driver lighting system | |
| CN102625519B (en) | Driving circuit capable of improving electric energy conversion efficiency and driving method thereof | |
| CN101715265A (en) | LED driving power supply control circuit and LED lamp by using same | |
| CN1909314A (en) | Electronic trip device with a power supply circuit means, and circuit breaker comprising such device | |
| CN101034798A (en) | Power convertor output protection circuit | |
| KR20120018460A (en) | Reverse polarity series type led and drive circuit | |
| CN1394383A (en) | Self-driven synchronous reftification circuit for low output voltage DC-DC converters | |
| CN1574591A (en) | Power supply for positive and negative output voltages | |
| CN102801308A (en) | Power supply device and lamp and vehicle including same | |
| CN1713474A (en) | Overload protecting circuit of transformer | |
| US6664660B2 (en) | Parallel power supply system with over-voltage protection circuit | |
| US20160050729A1 (en) | Drive circuit for illumination device and illumination device | |
| US20070223260A1 (en) | Power supply device with inrush current control circuit | |
| DE112015007243B4 (en) | solid state lighting assembly | |
| CN1713475A (en) | Overload protecting circuit of transformer | |
| DE102009050203B4 (en) | Device with a suppression circuit of a residual light | |
| CN1412946A (en) | Reversed polarity induction electric energy generation circuit of pulse power supply | |
| CN113162011A (en) | Overvoltage protection circuit and power supply circuit | |
| CN1659487A (en) | Measuring device used in process technology, comprising a central power supply unit | |
| CN1269280C (en) | Parallel power supply device with over voltage protection function | |
| CN2565230Y (en) | Electric arc detecting and protecting apparatus | |
| CN1319269A (en) | Power supply Device for protective device for switchgear | |
| CN101588671B (en) | Electronic ballast and detection circuit thereof for abnormal fluorescent tube |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |