CN2572665Y - Switch power source - Google Patents
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- CN2572665Y CN2572665Y CN 02249259 CN02249259U CN2572665Y CN 2572665 Y CN2572665 Y CN 2572665Y CN 02249259 CN02249259 CN 02249259 CN 02249259 U CN02249259 U CN 02249259U CN 2572665 Y CN2572665 Y CN 2572665Y
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Abstract
The utility model relates to a switch power source which comprises an input rectification filter circuit, a self-excited oscillation circuit, a surge voltage absorption circuit, a transformer, a short circuit protecting circuit, a secondary rectification filter circuit, a secondary voltage regulator circuit and a feedback control circuit, wherein the surge voltage absorption circuit is connected in parallel with the two ends of a primary winding TIA of the transformer, the feedback control circuit mainly inputs a feedback control signal into the self-excited oscillation circuit for controlling the on-off of a switch transistor by a pair of photoelectric couplers U1-A, U1-B. The two ends of a charging capacitor C4 supplying conduction voltage for a switch transistor are connected in parallel with a discharge circuit composed of a triode. Furthermore, the utility model is provided with the short circuit protecting circuit which prevents the charging capacitor C4 from being charged in an accelerated mode when an output is in a short circuit mode. The utility model is a switch power source without a special pulse width integration controller, has the advantages of small start-up current and sustained operating current, simple circuit and short circuit protection performance and can realize constant voltage output.
Description
Technical field
The utility model relates to a kind of Switching Power Supply, and especially a kind of have one-period ground and switch through the switching type power supply that is applied to the primary winding voltage.This Switching Power Supply is allowed very wide input voltage range, adapts to the voltage request of global different regions, is suitable for general DC power supply or charge power supply, is specially adapted to the charge power supply of cordless telephone, and the power supply of MD, CD and electronics hand account etc.
Background technology
General Switching Power Supply all is to adopt special-purpose pulsewidth integrated manipulator, for example " novel switched power supply practical technique " the 62nd, 63 page of Switching Power Supply of being introduced in the Electronic Industry Press---use pulsewidth integrated manipulator UC3842, it is the integrated circuit of applied current control (Current ModeControl) PWM.The deficiency of its existence is: 1, need special-purpose pulsewidth integrated manipulator, cost of manufacture height; 2, need bigger start and ongoing operation electric current; 3, the peripheral components requirement is more, is unfavorable for microminiaturization.
Summary of the invention
The purpose of this utility model is intended to overcome above-mentioned the deficiencies in the prior art, and proposing does not a kind ofly need that special-purpose pulsewidth integrated manipulator, start and ongoing operation electric current are little, circuit is simple and has the Switching Power Supply of short-circuit protection.
Realize the technical scheme of above-mentioned purpose: a kind of Switching Power Supply, comprise input rectifying filter circuit, self-maintained circuit, surge voltage absorbing circuit, transformer, short-circuit protection circuit and secondary commutation filter circuit, wherein:
Transformer T is made up of elementary winding T1-A, elementary winding T1-B and secondary winding T1-C;
The output of input rectifying filter circuit meets elementary winding T1-A;
Surge voltage absorbing circuit is attempted by the two ends of primary winding T1-A;
Self-maintained circuit is by R2, C4, R7 ~ R10, primary winding T1-B, switching transistor Q2, Q1 and diode D8 connect to form, the end ground connection of elementary winding T1-B, the other end is through resistance R 7, capacitor C 4, resistance R 2 connects the output of input rectifying filter circuit, the input of switching transistor Q2 and capacitor C 4, the anode of resistance R 2 and D8 also connects, the output of switching transistor Q2 is connected in series elementary winding T1-A and through R9 ground connection, the negative electrode of D8 connects the collection utmost point of transistor Q1, the emitter grounding of transistor Q1, between the base stage of transistor Q1 and the emitter-base bandgap grading and connect capacitor C 5, the base stage of transistor Q1 and connecting resistance R8, R10, the other end of resistance R 8 also connects the anode of elementary winding T1-B and D7, and the other end of resistance R 10 is through resistance R 9 ground connection;
Short-circuit protection circuit comprises resistance R 19, capacitor C 13 and diode D6; the grid of one termination switching transistor Q2 of resistance R 19; the negative electrode of another terminating diode D6 of resistance R 19 and an end of capacitor C 13, the plus earth of diode D6, the other end of C13 also meets R7 and C4.
The output of described secondary commutation filter circuit is provided with feedback control circuit, feedback control circuit is made up of photoelectronic coupler U1-A, U1-B, resistance R 11, secondary voltage stabilizing circuit, capacitor C 12, diode D7 and resistance R 5, the output of secondary commutation filter circuit connects secondary voltage stabilizing circuit through photoelectronic coupler U1-A, resistance R 11, the end ground connection of charging capacitor C12, the end of the negative electrode of the other end and D7 and photoelectronic coupler U1-B also connects, and the other end of photoelectronic coupler U1-B connects the base stage of transistor Q1 through resistance R 5.
Described secondary voltage stabilizing circuit comprises the constant voltage circuit that is made of R14, R15, C8, R16, R18 and U2, the end of R14 and R16 also connects the output of secondary commutation filter circuit, the negative electrode of another termination voltage-stabiliser tube U2 of R14, the other end of R16 connects the anode of voltage-stabiliser tube U2 through R18, and the R15 of series connection and C8 are attempted by between the negative electrode and the control utmost point of voltage-stabiliser tube U2.
Described secondary voltage stabilizing circuit also comprises by triode Q3, resistance R 13, capacitor C 10 and current-limiting resistance R12 and constitutes current-limiting control circuit, be attempted by the two ends of voltage-stabiliser tube U2 behind the collection utmost point of triode Q3, the base stage connecting resistance R13 respectively, capacitor C 10 is connected in parallel on emitter-base bandgap grading and the base stage two ends of Q3, and the output of secondary commutation filter circuit is in parallel with the emitter-base bandgap grading of Q3 after C11 ground connection through capacitor C 7.
At described capacitor C 4 two ends and be connected to discharge loop, discharge circuit comprises that resistance R 20, R6 and transistor Q4 form, and the base stage of transistor Q4 is through resistance R 20 ground connection, and the emitter-base bandgap grading of transistor Q4 connects the collection utmost point through C4 and R6 and forms discharge loop.
Described discharge loop comprises unidirectional conducting diode D10, and the emitter-base bandgap grading of transistor Q4 connects collection utmost point formation discharge loop through D10, C4 and R6.
Described input rectifying filter circuit is made up of diode bridge rectifier circuit and LC low pass filter, and the output of diode bridge rectifier circuit connects the LC low pass filter, and the output of LC low pass filter meets elementary winding T1-A.
Described input rectifying filter circuit comprises filter capacitor C1, common-mode inductor L1, diode rectifier bridge and filter capacitor C2, the input of common-mode inductor L1 also meets filter capacitor C1, and the output of common-mode inductor L1 is after the diode rectifier bridge rectification and meet filter capacitor C2.
Described surge voltage absorbing circuit is connected in series R4 after by R3, C3 parallel connection, D5 constitutes.
Described voltage stabilizing circuit is a voltage-stabiliser tube.
Switching Power Supply according to the such scheme making, press the work of flyback converter principle, when switching transistor is switched on, electric current flows through transformer and it is magnetized, when switching transistor is turned off, magnetic energy will be coupled to secondary, secondary control circuit control by transformer and be output as constant voltage source or constant-current supply.Its tangible technique effect is: 1, do not need special-purpose pulsewidth integrated manipulator, realize the effect of Current Control PWM with minimum components and parts.2, feedback control circuit and output voltage stabilizing circuit are set, can both provide overvoltage and overcurrent and protect timely and regulate.3, short-circuit protection circuit is set, power diminishes when making short circuit, and is safe and reliable.4, discharge loop is set, can effectively reduces when underload and the switching frequency of switching transistor during the input too high voltages, avoid the superheating phenomenon of transistor Q2, the useful life of improving Q2.5, do not have complicated circuit, it is very little that static state is kept operating current, only needs very little start and ongoing operation electric current, thereby, the less miniaturized component of optional diligent loss-rate.6, this Switching Power Supply active and passive device of very few number, therefore very cost saving.Simultaneously, because number of devices seldom, so be easy to be made into small-sized portable Switching Power Supply, is specially adapted to the power supply of charge power supply and MD, CD and the electronics hand account etc. of cordless telephone.7, the very wide input voltage range of design tolerable of entire circuit is to adapt to the voltage request of global different regions.In sum, the utility model is a kind of have short-circuit protection, small-sized and cheap Switching Power Supply.
Description of drawings
Fig. 1 is a circuit diagram of the present utility model.
Fig. 2 is a kind of input rectifying filter circuit figure.
Embodiment
Embodiment: with reference to Fig. 1; a kind of Switching Power Supply comprises input rectifying filter circuit, self-maintained circuit, surge voltage absorbing circuit, transformer, discharge loop, short-circuit protection circuit, secondary commutation filter circuit, secondary voltage stabilizing circuit and feedback control circuit.
Constitute the input rectifying filter circuit by R1, D1-D4, C1, L1 and C2.By the surge voltage absorbing circuit that R3, C3, R4, D5 constitute, surge voltage absorbing circuit is attempted by the two ends of primary winding T1-A.Form transformer T by elementary winding T1-A, elementary winding T1-B and secondary winding T1-C.
Self-maintained circuit is by R2, C4, R7 ~ R10, primary winding T1-B, switching transistor Q2, Q1 and diode D8 connect to form, the end ground connection of elementary winding T1-B, the other end is through resistance R 7, capacitor C 4, resistance R 2 connects the output of input rectifying filter circuit, switching transistor Q2 is the MOS field-effect transistor, the input of switching transistor Q2 and capacitor C 4, the anode of resistance R 2 and D8 also connects, the output of switching transistor Q2 is connected in series elementary winding T1-A and through R9 ground connection, the negative electrode of D8 connects the collection utmost point of transistor Q1, the emitter grounding of transistor Q1, between the base stage of transistor Q1 and the emitter-base bandgap grading and connect capacitor C 5, the base stage of transistor Q1 and connecting resistance R8, R10, the other end of resistance R 8 also connects the anode of elementary winding T1-B and D7, the other end of resistance R 10 is through resistance R 9 ground connection
At capacitor C 4 two ends and be connected to discharge loop, discharge circuit comprises that resistance R 20, R6 and transistor Q4 form, and the base stage of transistor Q4 is through resistance R 20 ground connection, and the emitter-base bandgap grading of transistor Q4 connects the collection utmost point through C4 and R6 and forms discharge loop.
Short-circuit protection circuit comprises resistance R 19, capacitor C 13 and diode D6; the grid of one termination switching transistor Q2 of resistance R 19; the negative electrode of another terminating diode D6 of resistance R 19 and an end of capacitor C 13, the plus earth of diode D6, the other end of C13 also meets R7 and C4.
Constitute the secondary commutation filter circuit by D9, C6 and C7.The output of secondary commutation filter circuit is provided with feedback control circuit, feedback control circuit is made up of photoelectronic coupler U1-A, U1-B, resistance R 11, secondary voltage stabilizing circuit, capacitor C 12, diode D7 and resistance R 5, the output of secondary commutation filter circuit connects secondary voltage stabilizing circuit through photoelectronic coupler U1-A, resistance R 11, the end ground connection of charging capacitor C12, the end of the negative electrode of the other end and D7 and photoelectronic coupler U1-B also connects, and the other end of photoelectronic coupler U1-B connects the base stage of transistor Q1 through resistance R 5.
Secondary voltage stabilizing circuit comprises constant voltage circuit and current-limiting control circuit, constant voltage circuit is made up of R14, R15, C8, R16, R18 and U2, the end of R14 and R16 also connects the output of secondary commutation filter circuit, the negative electrode of another termination voltage-stabiliser tube U2 of R14, the other end of R16 connects the anode of voltage-stabiliser tube U2 through R18, and the R15 of series connection and C8 are attempted by between the negative electrode and the control utmost point of voltage-stabiliser tube U2.Current-limiting control circuit comprises by triode Q3, resistance R 13, capacitor C 10 and current-limiting resistance R12 and constitutes current-limiting control circuit, be attempted by the two ends of voltage-stabiliser tube U2 behind the collection utmost point of triode Q3, the base stage connecting resistance R13 respectively, capacitor C 10 is connected in parallel on emitter-base bandgap grading and the base stage two ends of Q3, and the output of secondary commutation filter circuit is in parallel with the emitter-base bandgap grading of Q3 after C11 ground connection through capacitor C 7.
The output of secondary voltage stabilizing circuit is provided with filter circuit; filter circuit constitutes a low pass LC filter by L2, C9, and its resonance frequency can be reduced to the ripple of output current very low far below switching frequency; voltage-stabiliser tube Z1 is as output over-voltage protection, to prevent too high output voltage.
The course of work: receive civil power when this Switching Power Supply and get on, capacitor C1 and C2 are charged to the peak value of supply voltage immediately, supply voltage is through the high resistant resistance R 2 of series connection, C4,7 pairs of elementary winding T1-B chargings of low-resistance resistance R, voltage on C4 rises to the conducting voltage of Q2, Q2 promptly begins conducting, positive feedback voltage along with elementary winding T1-B, switching transistor Q2 enters the deep layer conducting, the electric current of primary winding T1-A begins to rise, this electric current flow through simultaneously Q2 and R9, voltage on R9 rises and makes the Q1 conducting, voltage on the Q2 grid reduces and makes the output current of switching transistor Q2 reduce, secondary winding T1-C output voltage reduces, thereby makes output voltage maintain a steady state value.Simultaneously, elementary winding T1-B produces a negative voltage immediately and makes Q2 quicken to end.In this process, the energy that is stored among the transformer T begins to be stored into C7 through secondary winding T1-C, D9, C6, and the energy in transformer T discharges and finishes, and switching transistor Q2 is conducting again more again, finishes a cycle of oscillation.When output voltage was higher than the partial pressure value that is set by R16 and R18, the U2 cathode voltage descended, and the electric current of U1A and U1B can increase.At this moment, the bias voltage that the electric current of U1B produces on resistance R 10 increases, and makes Q1 do sth. in advance conducting, and the ON time of switching transistor Q2 reduces thereupon, and final, output voltage can be adjusted on the predefined numerical value of the voltage divider of being made up of R16 and R18 automatically.When load current very little, voltage can maintain this preset value, if load current constantly increases, the voltage of R12 can be followed rising, when the voltage on the R12 is raised to set point, Q3 is conducting immediately, the electric current of photoelectronic coupler U1A, U1B increases, and Q1 does sth. in advance conducting, and the ON time of switching tube Q2 also reduces thereupon, the energy that is stored in transformer also reduces, the output voltage of secondary winding T1-C thereby reduction.After output voltage reduced, therefore output current also reduced, and ultimate current can maintain near the preset value.At this moment, this Switching Power Supply is operated in constant current state, and constant current output is provided.
In above-mentioned adjustment process, when making the output current minimizing of switching transistor Q2 whenever the minimizing of the voltage on the Q2 grid, elementary winding T1-B flyback immediately produces a negative voltage, and this negative voltage makes Q2 quicken to end on the one hand; On the other hand, under the negative voltage effect when elementary winding T1-B flyback, triode Q4 conducting, the discharge loop discharge that charging capacitor C4 connects formation through the collection utmost point and emitter-base bandgap grading, the diode D10 of resistance R 6, triode Q4, before taking place feasible next cycle of oscillation, C4 will charge to the conducting voltage of Q2 through R2, thereby produces a time of delay, when preventing underload and high voltage when input too fast switching frequency to infringement that switching transistor caused.
In the charging process of capacitor C 4,, provide another path to make the C4 charging by accelerated charging resistance R 19.Because normal operating frequency is by the voltage decision of accelerated charging resistance R 19 and C13; when output short-circuit, the voltage at T1C two ends is very little, thereby the voltage of the voltage at T1B two ends and C13 becomes very little; output frequency and power diminish, and C13, D10 and R19 will bring into play short-circuit protection function.
Switching Power Supply changes the inversion frequency of switching transistor Q2 by the function of load.Its operating frequency is approximately by 50K to 200KHZ, and operating frequency is the highest when underload maximum input voltage; On the contrary, frequency is minimum when maximum load and minimum input voltage.
If the voltage control required precision is not high, voltage stabilizing circuit in the secondary control circuit (R14, R15, C8, R16, R18 and U2) can be replaced by single voltage-stabiliser tube, the negative electrode of voltage-stabiliser tube is connected on the collection utmost point of Q3, and the anode of voltage-stabiliser tube is connected on the ground end of output, the i.e. negative pole of capacitor C 9.
If the numerical value of C4 is not too big, the emitter-base bandgap grading of Q4 and collection extremely can reverse grafts, can save D10; D10 can be connected on the also contact of R7, D7 and R8; The serial connection position of R7 and C4 is interchangeable; The value of R5, R6 and C12 can be zero (C12 disconnection); R19 can be infinitely great or disconnection does not exist, and C4 is not carried out accelerated charging.And the voltage stabilizing circuit in the secondary control circuit (R14, R15, C8, R16, R18 and U2) can be replaced by single voltage-stabiliser tube, and the negative electrode of voltage-stabiliser tube is connected on the collection utmost point of Q3, and the anode of voltage-stabiliser tube is connected on the ground end of output, i.e. the negative pole of capacitor C 9.
The also available another kind of input rectifying filter circuit as shown in Figure 2 of input rectifying filter circuit among Fig. 1 replaces, in Fig. 2, the input rectifying filter circuit comprises filter capacitor C1, common-mode inductor L1, diode rectifier bridge and filter capacitor C2, the input of common-mode inductor L1 also meets filter capacitor C1, and the output of common-mode inductor L1 is after the diode rectifier bridge rectification and meet filter capacitor C2.
The present embodiment Switching Power Supply is provided with surge absorbing circuit, and purpose is the surge voltage that absorbs switching transistor, thereby reduces the noise of Switching Power Supply.This circuit can change over single formed (D5 short circuit, R3 open a way) by R4 and C3 and changes a voltage-stabiliser tube into again or with R4, R3, C3, the negative electrode of the negative electrode of voltage-stabiliser tube and diode D5 joins, the anode of voltage-stabiliser tube is connected on the positive pole of capacitor C2, and these three kinds of surge absorbing circuits also are applicable in the utility model.
The present embodiment Switching Power Supply also can be made into two or above output, as long as add one or more windings at transformer, one or more current rectifying and wave filtering circuits just can be realized the Switching Power Supply of many group outputs.
Claims (10)
1; a kind of Switching Power Supply; comprise the input rectifying filter circuit; self-maintained circuit; surge voltage absorbing circuit; transformer and secondary commutation filter circuit; transformer T is by elementary winding T1-A; elementary winding T1-B and secondary winding T1-C form; the output of input rectifying filter circuit meets elementary winding T1-A; surge voltage absorbing circuit is attempted by the two ends of primary winding T1-A; self-maintained circuit is by R2; C4; R7 ~ R10; primary winding T1-B; switching transistor Q2; Q1 and diode D8 connect to form; the end ground connection of elementary winding T1-B; the other end is through resistance R 7; capacitor C 4; resistance R 2 connects the output of input rectifying filter circuit; the input of switching transistor Q2 and capacitor C 4; the anode of resistance R 2 and D8 also connects; the output of switching transistor Q2 is connected in series elementary winding T1-A and through R9 ground connection; the negative electrode of D8 connects the collection utmost point of transistor Q1; the emitter grounding of transistor Q1; between the base stage of transistor Q1 and the emitter-base bandgap grading and connect capacitor C 5; the base stage of transistor Q1 and connecting resistance R8; R10; the other end of resistance R 8 also connects the anode of elementary winding T1-B and D7; the other end of resistance R 10 is through resistance R 9 ground connection; it is characterized in that: be provided with short-circuit protection circuit; short-circuit protection circuit comprises resistance R 19; capacitor C 13 and diode D6; the grid of one termination switching transistor Q2 of resistance R 19; the negative electrode of another terminating diode D6 of resistance R 19 and an end of capacitor C 13; the plus earth of diode D6, the other end of capacitor C 13 and connecting resistance R7 and capacitor C 4.
2, according to the described a kind of Switching Power Supply of claim 1, it is characterized in that: the output of described secondary commutation filter circuit is provided with feedback control circuit, feedback control circuit is by photoelectronic coupler U1-A, U1-B, resistance R 11, secondary voltage stabilizing circuit, capacitor C 12, diode D7 and resistance R 5 are formed, the output of secondary commutation filter circuit is through photoelectronic coupler U1-A, resistance R 11 connects secondary voltage stabilizing circuit, the end ground connection of charging capacitor C12, the end of the negative electrode of the other end and D7 and photoelectronic coupler U1-B also connects, and the other end of photoelectronic coupler U1-B connects the base stage of transistor Q1 through resistance R 5.
3, according to the described a kind of Switching Power Supply of claim 2, it is characterized in that: described secondary voltage stabilizing circuit comprises the constant voltage circuit that is made of R14, R15, C8, R16, R18 and U2, the end of R14 and R16 also connects the output of secondary commutation filter circuit, the negative electrode of another termination voltage-stabiliser tube U2 of R14, the other end of R16 connects the anode of voltage-stabiliser tube U2 through R18, and the R15 of series connection and C8 are attempted by between the negative electrode and the control utmost point of voltage-stabiliser tube U2.
4, according to the described a kind of Switching Power Supply of claim 3, it is characterized in that: described secondary voltage stabilizing circuit also comprises by triode Q3, resistance R 13, capacitor C 10 and current-limiting resistance R12 and constitutes current-limiting control circuit, be attempted by the two ends of voltage-stabiliser tube U2 behind the collection utmost point of triode Q3, the base stage connecting resistance R13 respectively, capacitor C 10 is connected in parallel on emitter-base bandgap grading and the base stage two ends of Q3, and the output of secondary commutation filter circuit is in parallel with the emitter-base bandgap grading of Q3 after C11 ground connection through capacitor C 7.
5, according to the described a kind of Switching Power Supply of claim 1 ~ 4, it is characterized in that: at described capacitor C 4 two ends and be connected to discharge loop, discharge circuit comprises that resistance R 20, R6 and transistor Q4 form, the base stage of transistor Q4 is through resistance R 20 ground connection, and the emitter-base bandgap grading of transistor Q4 connects collection utmost point formation discharge loop through C4 and R6.
6, according to the described a kind of Switching Power Supply of claim 5, it is characterized in that: described discharge loop comprises unidirectional conducting diode D10, and the emitter-base bandgap grading of transistor Q4 connects collection utmost point formation discharge loop through D10, C4 and R6.
7, according to the described a kind of Switching Power Supply of claim 5, it is characterized in that: described input rectifying filter circuit is made up of diode bridge rectifier circuit and LC low pass filter, the output of diode bridge rectifier circuit connects the LC low pass filter, and the output of LC low pass filter meets elementary winding T1-A.
8, according to the described a kind of Switching Power Supply of claim 7, it is characterized in that: described input rectifying filter circuit comprises filter capacitor C1, common-mode inductor L1, diode rectifier bridge and filter capacitor C2, the input of common-mode inductor L1 also meets filter capacitor C1, and the output of common-mode inductor L1 is after the diode rectifier bridge rectification and meet filter capacitor C2.
9, described according to Claim 8 a kind of Switching Power Supply is characterized in that: described surge voltage absorbing circuit is connected in series R4 after by R3, C3 parallel connection, D5 constitutes.
10, described according to Claim 8 a kind of Switching Power Supply, it is characterized in that: described voltage stabilizing circuit is a voltage-stabiliser tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02249259 CN2572665Y (en) | 2002-09-20 | 2002-09-20 | Switch power source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02249259 CN2572665Y (en) | 2002-09-20 | 2002-09-20 | Switch power source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2572665Y true CN2572665Y (en) | 2003-09-10 |
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ID=33719721
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02249259 Expired - Fee Related CN2572665Y (en) | 2002-09-20 | 2002-09-20 | Switch power source |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2572665Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102044981A (en) * | 2009-10-16 | 2011-05-04 | 深圳Tcl新技术有限公司 | Switching power supply with capacitor discharge circuit |
| CN103051197A (en) * | 2013-01-16 | 2013-04-17 | 绍兴光大芯业微电子有限公司 | Primary-side-control based control circuit structure for flyback switching power supply |
-
2002
- 2002-09-20 CN CN 02249259 patent/CN2572665Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102044981A (en) * | 2009-10-16 | 2011-05-04 | 深圳Tcl新技术有限公司 | Switching power supply with capacitor discharge circuit |
| CN102044981B (en) * | 2009-10-16 | 2013-12-25 | 深圳Tcl新技术有限公司 | Switching power supply with capacitor discharge circuit |
| CN103051197A (en) * | 2013-01-16 | 2013-04-17 | 绍兴光大芯业微电子有限公司 | Primary-side-control based control circuit structure for flyback switching power supply |
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| CF01 | Termination of patent right due to non-payment of annual fee |