CN2662529Y - A positively exciting constant current source - Google Patents
A positively exciting constant current source Download PDFInfo
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- CN2662529Y CN2662529Y CN 03276727 CN03276727U CN2662529Y CN 2662529 Y CN2662529 Y CN 2662529Y CN 03276727 CN03276727 CN 03276727 CN 03276727 U CN03276727 U CN 03276727U CN 2662529 Y CN2662529 Y CN 2662529Y
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Abstract
The utility model relates to a positive incentive constant-current source, which belongs to the high-frequency switching power supply field of the power electronic technology and comprises a positive incentive high-frequency isolated DC/DC converter, a waveform reference generation circuit, an outer ring current control circuit and an inner ring peak current limiting circuit. The positive incentive high-frequency isolated DC/DC converter uses a milliohm precision resistance [R3] as the detection of the output current, and the current at the primary side of the transformer is detected by the resistance [R2]. The waveform reference generation circuit processes the addition of waveforms to the precise sine reference and the direct-current component by the homophase summing circuit of an operational amplifier, and the result is regarded as the specified value of the last controlled current. The utility model has a stable and reliable work, and can output the constant current source of AC ripple superimposing the constant amplitude and frequency, and can be used in the electrochemical electrolysis occasion, such as the ozone generation and other occasions.
Description
Technical field
The utility model provides a kind of positive activation type constant-current source, and it belongs to the high frequency switch power technology of electric and electronic technical field.
Background technology
High frequency switch power is because its advantage efficient, high power density has purposes very widely in daily life and commercial Application.Yet Switching Power Supply commonly used generally is a voltage source, and for the switching mode current source document announcement is arranged seldom really, for the ripple of the current source of constant output, always wishes that it is the smaller the better.And for some special application scenario, occasion as the ozone generation, this additional low-frequency ripple is very necessary, the scheme of generally taking be stable be the DC component that will export, and the alternating current component of stack produces by the concussion of exporting, this control strategy is difficult to the ratio of control alternating current component and DC component, and there is tangible distortion in the AC wave shape of output.
In the 1st phase of " power electronic technology " calendar year 2001 " the resonant charging formula pulse laser power supply " literary composition, introduced the pulse laser power supply that a kind of resonance discharges and recharges, it is a kind of control idea of voltage source in itself.Adopt series resonance, improved the requirement of device to voltage and current stress, and had only a pi regulator, the dynamic response of power supply is slow.
Related electrical discharge machining pulse power in " power electronic technology " in April, 2002 " adopting the research of the novel electrical discharge machining pulse power of the Current Control Strategy " literary composition.Prime is output as the constant-current source of no low frequency pulsating, adopt inductance to carry out current limliting, though compare with traditional resistance current limliting, reliability and efficient all increase, but current limliting truly, because the high frequency current spikes on former limit through a flat ripple inductance after, control system can't be responsive to this current spike.
The utility model content
The purpose of this utility model is to overcome deficiency of the prior art, provides that a kind of principle is simple, working stability is reliable, and can export the constant-current source of the AC ripple of stack constant amplitude and frequency.
The utility model comprises: positive activation type high-frequency isolation DC/DC converter and control circuit.
Described positive activation type high-frequency isolation DC/DC converter adopts the detection of the precision resistance R3 of milliohm level as output current, and the electric current on the former limit of transformer adopts resistance R 2 to detect.Described control circuit mainly comprises sine wave generating circuit, adopts the benchmark generative circuit of waveform superimposing technique, the active amplifying circuit of sampling weak signal, circuit takes place in the signal conditioning circuit of milliohm level resistance sampling, PWM, the electric current outer shroud is regulated and the interior ring of peak current current-limiting circuit.Described benchmark generative circuit is that accurate sinusoid fiducial and DC component are carried out the waveform stack with the homophase summing circuit of amplifier, given as the electric current that will control at last.Described outer shroud current control circuit is that the ohmically voltage of detection is carried out active amplification through amplifier after the follower, and its output compares with waveform reference, adopts after the proportional plus integral control, and its output is isolated through the light lotus root is linear, sends into current regulator.The circular current current-limiting circuit is with the feedback of the voltage on the R2 as current regulator in described, and the adjuster of current inner loop adopts the current regulator of UC384X.
The utility model becomes direct current to the alternating voltage of input through rectification, adopts high-frequency inversion later on, becomes discrete pulse, becomes direct current through high-frequency rectification, filters wherein radio-frequency component with low-pass filter circuit.When input voltage or load change, change the pulsewidth of power tube, to keep the constant of output current.And the waveform of output current is decided by control; Adopt the waveform superimposing technique, generate accurate benchmark, and the ratio of alternating current component in the benchmark and DC component is identical with desired output, and the frequency of alternating current component is also identical with desired output in the benchmark.Adopt dual Current Control Technology from control mode, both generated the constant current that to export, limited the peak value of electric current in the power device again and reduced requirement power tube current stress.Peak current and output current on the utility model while sampled power pipe, can accomplish current limliting truly, compare that the system dynamics response is faster with above-mentioned Laser Power Devices scheme, and compare with above-mentioned electrical discharge machining pulse power, can accomplish current limliting truly.Adopt the waveform stack on the control circuit, generate needed fiducial value, because existing direct current has alternating current component again in the benchmark, and what adopt is direct feedback technique, so output must be followed the variation of benchmark, along with the variation of time, output waveform can distortion.
Description of drawings
Fig. 1 is a fundamental diagram of the present utility model;
Fig. 2 is the circuit diagram of the utility model normal shock isolation type high frequency DC/DC converter;
Fig. 3 is the control circuit figure of the utility model embodiment;
Fig. 4 is that Fig. 3 flows through electric current in the power tube;
The expansion of electric current in Fig. 5 power tube;
Given (CH1) of the outer circular current of Fig. 6 and feedback (CH2);
The waveform of Fig. 7 output current (100mv/A).
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is further specified.
The utility model comprises: positive activation type high-frequency isolation DC/DC converter and control circuit.
Operation principle as shown in Figure 1, ac output voltage obtains direct voltage after rectification, pass through high-frequency inversion then, obtain the high-frequency impulse ripple, isolate by the high frequency transformer transformation, after process high-frequency rectification and low-pass filtering, obtain needed electric current then.Because output current is a controlling object, so output current will be introduced FEEDBACK CONTROL, through current detecting and active amplification, feedback as the adjusting of electric current outer shroud, accurate sinusoidal take place and dc reference given, by the waveform stack, given as the adjusting of electric current outer shroud, the output that the electric current outer shroud is regulated is through the holding wire sexual isolation, as current inner loop regulate given, after interior circular current detects, as the feedback of current inner loop, output pwm signal then, the switch of control high-frequency inversion bridge.
Fig. 2 is the circuit diagram of normal shock isolation type high frequency DC/DC converter.Alternating current is through the RECT1 rectification, capacitor C 1 DC filtering, and capacitor C 1 positive pole, the end of the same name of transformer T1, C2, R1 connect 2 pin of rectifier bridge, and the non-same polarity on the former limit of transformer T1 connects the D utmost point of switching tube Q1, and the S utmost point of switching tube Q1 connects the ground on former limit by resistance R 2.4 pin ground connection of rectifier bridge.D1, R1, C2 are for absorbing circuit, and wherein the anode of D1 connects the D end of Q1, and the negative electrode of D1 connects the other end of C2 and R1.After the secondary process rectifying tube PD1 rectification of transformer, pass through L1, C3 low-pass filtering again, R0 is that load resistance, R3 are the detection resistance of output current.Wherein the secondary of transformer T1 connects two anodes of PD1, and negative electrode connects inductance L 1 one ends, and the positive pole of another termination capacitor C 3 of L1 and load R0, the end of another termination R3 of R0, the ground of another termination secondary of R3.
Operation principle becomes direct current to the alternating voltage of input through rectification as shown in Figure 1, adopts high-frequency inversion later on, becomes discrete pulse, becomes direct current through high-frequency rectification, filters wherein radio-frequency component with low-pass filter circuit.When input voltage or load change, change the pulsewidth of power tube, to keep the constant of output current.
Control circuit is seen Fig. 3: mainly comprise the benchmark generative circuit of drawing together sine wave generating circuit, adopting the waveform superimposing technique, the active amplifying circuit of sampling weak signal, circuit takes place in the signal conditioning circuit of milliohm level resistance sampling, PWM, the electric current outer shroud is regulated and the interior ring of peak current current-limiting circuit.Concrete control circuit as shown in Figure 3, wherein VCC and VC value are the 15V and the power supply on ground altogether not.Sinusoidal wave generation circuit is the ICL8038 function generator, 6 corner connection VCC of this chip, and 11 pin ground connection, R3 and R4 connect 5 jiaos and 4 jiaos of this chip.8 pin and 7 jiaos of short circuits, 9 jiaos meet positive supply VCC by resistance R 2.10 jiaos by capacitor C 1 ground connection, and 12 jiaos by resistance R 1 ground connection, and C21 separates lotus root electric capacity for this chip, and two ends connect VCC and ground respectively.2 pin of this chip are output as the low frequency pulsating of a stack DC component, and the frequency of this low frequency pulsating is identical with the frequency of the low frequency pulsating of output current, and it exports y
1=A
1Sin (wt)+D
1(V), A wherein
1Be sinusoidal wave amplitude, D
1Be the size of direct current biasing, y1 connects the in-phase end 3 of LM324 by resistance R 7, and R5 and R6 are bleeder circuit, one of R5 and R6 terminates at together, and another termination VCC of R5, the other end ground connection of R6, dividing potential drop connects 3 pin of LM324 later on through resistance R 8, R33 connects 3 pin of LM32 to ground.R9 connects 2 pin and the ground of LM324, and R8 connects 2 pin and the output pin 1 of LM324.This output pin 1 connects 10 pin of LM324 through R13.The electric current I o of the output of sampling connects 5 pin of LM324 through resistance R 20, and connects a resistance R 21 between 6 pin and 7 pin, and R22 is connected between 7 pin and 12 pin, and R23 is connected between 12 pin and the ground.R24 is connected between 13 pin and the ground, and R38 and C38 series connection are in the middle of 13 and 14, and R25 also is connected in the middle of 13 and 14.Export 9 pin that 14 pin process resistance R 14 meets LM324, R11 and capacitor C 2 proportion of composing integrating circuit are connected on 9 pin and 8 pin of LM324.The anode of exporting the input of 8 pin process resistance R 12 and light lotus root PC817 joins the minus earth of input.The emitter-base bandgap grading of output is by resistance R 16 ground connection, voltage on the resistance R 16 is received 1 pin of UC3845 then, IP is the voltage on the resistance R 3 among Fig. 2, this voltage is connected on 3 pin of UC3845 through the low-pass filter circuit of R17 and C26 composition, and connect by resistance R 19 between 4 pin of this chip and 8 pin, and 8 pin are by capacitor C 27 ground connection, 7 pin meet positive supply VC, and 4 pin are by capacitor C 25 ground connection, 6 pin of output amplify by the triode of Q1～Q4, and it amplifies output connects switching tube in the power circuit by a resistance R 35 MG end.And R34 is the bleed off resistance of grid, is connected on MG and MS end.Concrete operation principle is expressed as follows: in order to adjust the promptly sinusoidal amplitude of final benchmark and the ratio of direct current biasing, the homophase summing circuit has been adopted in the waveform stack, the amplitude of the given benchmark medium and low frequency of assurance outer shroud alternating current component and the ratio of DC component are consistent with an output electric current that requires, dc reference
Because R
8//R
7//R
33=R
9//R
10So, the output of summation equally:
The output of this homophase summation is given through the forward that a resistance connects the outer shroud electric current loop.Io among Fig. 3 is that output current is through the later amount of resistance detection, i.e. pressure drop on the resistance R 3 among Fig. 1.In order to reduce the detection loss, because sampling resistor is a milliohm level resistance, pressure drop on the sampling resistor is very low, and the as easy as rolling off a log influence that is interfered of weak signal and distortion, so adopt active amplifying technique, promptly use the in-phase proportion circuit, wherein, the end of Io connecting resistance R20, and 5 pin (in-phase end) of another termination U3B of resistance R 20, the end of 6 pin (negative phase end) the connecting resistance R21 of U3B then, and the output of another termination U3B of R21, and the end of the output connecting resistance R22 of U3B, 12 ends of another termination amplifier U3D of R22,12 ends are by resistance R 23 ground connection, and the 13 termination R24 of U3D, R38, the end of R25.Another termination control ground of R24, the output 14 of another termination U3D of R25, the other end of R38 are received the output of U3D by polyphone C38.And the end of the 14 pin connecting resistance R14 of U3D, and 9 pin of another termination U3C of R14, and 9 pin of U3C connect its 8 pin by resistance R 11 and C2, and its 8 pin connects the end of R12, and the anode of another termination optocoupler U4 of R12, and the collector electrode of PC817 meets VC and its emitter-base bandgap grading connects the end of R16, and another termination control ground of R16.The emitter-base bandgap grading of Pc817 connects 1 pin of Uc3845.Do not consider the effect of R38 and C38, think that its path is a high-impedance state to low-frequency ac and DC component, the then output of amplifier U3D
And y
3Through a resistance, connect the negative of outer shroud electric current loop, R11, C2 are pi regulator.Level needs to isolate before and after considering power circuit, so having passed through a smooth lotus root PC817, the output of pi regulator carried out linear isolation, and the output of the Voltage loop of UC3845 is received in the output of light lotus root, and the voltage regulator of this current mode pwm chip is not used, and has only used the current regulator of this chip.IP among Fig. 3 is the current detecting in the power device, voltage on the resistance R 2 among Fig. 1 just, this voltage is through R17, the low-pass filtering of C26 is sent into the end of oppisite phase of current regulator later on, compare with the given of current regulator, after the proportional integral adjusting, constantly output duty cycle is less than 0.5 PWM ripple, drive amplification through Q1～Q4 and promote main power MOSFET Q1 among Fig. 1 later on, Q1 wherein, the base stage of Q3 connects 6 pin of UC3845, Q1 then, the emitter of Q3 meets Q2, the Q4 base stage, and Q2, the emitter-base bandgap grading of Q4 meets driving resistor R35, and the other end MG of R35 connects the end of R34, and another termination control ground of R34.And MG is connected to the grid of the Q1 of Fig. 2.4 pin of UC3845 connect its 8 pin by resistance R 19, and 8 pin are by C27 ground connection.5 pin ground connection, and 7 pin meet control power supply VC.4 pin are by C25 ground connection.
Fig. 2 is a normal shock isolation type high frequency DC/DC converter, by the control circuit of Fig. 3 it is controlled.
The technical solution of the utility model has obtained checking on a 60W model machine.The working condition of this model machine is as follows: input ac voltage is 220V ± 20%, exports the low frequency 100Hz that superposeed, and amplitude is the sine wave of 2～4V, and the mean value of output current is 12A, and the output voltage excursion is 0～5V, and switching frequency is 100KHz.The used device parameters of experimental prototype is: 1. the high frequency transformer magnetic core is EI40B, former limit N1=68 circle, φ=2 strands of 0.3mm copper cash and around.Secondary N2=4.25 circle, φ=32 strands of 0.3mm copper cash and around.2. the filter inductance magnetic core is ring-like sendust core, and φ is outer=47mm, in the φ=24mm, and thickness d=18mm, sensibility reciprocal L=90uH adopts copper cash 38 circles of φ=0.3mm and around, totally 21 circles.3. power device Q1 is SSH5N90.4. rectifier diode PD1 is 6045PT.5. C3 is a high-frequency filter capacitor, is 47uf/25V.6. R3 is the inspection leakage resistance, and value is 0.02 ohm.7. former frontier inspection leakage resistance R2 is 1 ohm.Experimental result as shown in Figure 4 to 7.Wherein Fig. 4 and Fig. 5 are the pressure drop on the linear resistance R2 (shown in Figure 2), have also reacted the Changing Pattern of primary current.As seen from Figure 4, the envelope of primary current modulation is sinusoidal.And the figure that Fig. 5 launches for primary current, owing to adopted the peak current sampling, and so current waveform is very smooth, no spike.Fig. 6 is the waveform that outer circular current is given and feed back, and wherein Ch1 is the given of electric current, and Ch2 is a current feedback signal.Fig. 7 is the waveform of output current.
The utility model order phase civil power just can be used, and in the occasion of other power supply, just can use as long as reasonably design high frequency transformer.Be mainly used in the occasion of the electrolysis in the electrochemistry, as ozone generation etc.
Claims (3)
1, a kind of positive activation type constant-current source is characterized in that it comprises: positive activation type high-frequency isolation DC/DC converter and control circuit; The precision resistance [R3] of positive activation type high-frequency isolation DC/DC converter using milliohm level is as the detection of output current, and the electric current on the former limit of transformer adopts resistance [R2] to detect; Described control circuit mainly comprises sine wave generating circuit, adopts the benchmark generative circuit of waveform superimposing technique, the active amplifying circuit of sampling weak signal, circuit takes place in milliohm level resistance sampling signal conditioning circuit, PWM, the electric current outer shroud is regulated and the interior ring of peak current current-limiting circuit; Described benchmark generative circuit is that accurate sinusoid fiducial and DC component are carried out the waveform stack with the homophase summing circuit of amplifier, given as the electric current that will control at last; Described outer shroud current control circuit is that the ohmically voltage of detection is carried out active amplification through amplifier after the follower, and its output compares with waveform reference, adopts after the proportional plus integral control, and its output is isolated through the light lotus root is linear, sends into current regulator; The circular current current-limiting circuit is with the feedback of the voltage on the R2 as current regulator in described, and the adjuster of current inner loop adopts the current regulator of UC384X.
2, positive activation type constant-current source according to claim 1, it is characterized in that in the said normal shock isolation type high frequency DC/DC converter, alternating current is through the RECT1 rectification, capacitor C 1 DC filtering, capacitor C 1 positive pole, the end of the same name of transformer T1, C2, R1 connect 2 pin of rectifier bridge, the non-same polarity on the former limit of transformer T1 connects the D utmost point of switching tube Q1, and the S utmost point of switching tube Q1 connects the ground on former limit by resistance R 2.4 pin ground connection of rectifier bridge; D1, R1, C2 are for absorbing circuit, and wherein the anode of D1 connects the D end of Q1, and the negative electrode of D1 connects the other end of C2 and R1; After the secondary process rectifying tube PD1 rectification of transformer, pass through L1, C3 low-pass filtering again, R0 is that load resistance, R3 are the detection resistance of output current.Wherein the secondary of transformer T1 connects two anodes of PD1, and negative electrode connects inductance L 1 one ends, and the positive pole of another termination capacitor C 3 of L1 and load R0, the end of another termination R3 of R0, and the ground of another termination secondary of R3.
3, positive activation type constant-current source according to claim 1, the sine wave generating circuit that it is characterized in that said control circuit is the ICL8038 function generator, 6 corner connection VCC of this chip, 11 pin ground connection, R3 and R4 connect 5 jiaos and 4 jiaos of this chip; 8 pin and 7 jiaos of short circuits, 9 jiaos meet positive supply VCC by resistance R 2; 10 jiaos by capacitor C 1 ground connection, and 12 jiaos by resistance R 1 ground connection, and C21 separates lotus root electric capacity for this chip, and two ends connect VCC and ground respectively; 2 pin of this chip are output as the low frequency pulsating of a stack DC component, and the frequency of this low frequency pulsating is identical with the frequency of the low frequency pulsating of output current, and it exports y
1=A
1Sin (wt)+D
1(V), A wherein
1Be sinusoidal wave amplitude, D
1Be the size of direct current biasing, y1 connects the in-phase end 3 of LM324 by resistance R 7, and R5 and R6 are bleeder circuit, one of R5 and R6 terminates at together, and another termination VCC of R5, the other end ground connection of R6, dividing potential drop connects 3 pin of LM324 later on through resistance R 8, R33 connects 3 pin of LM32 to ground; R9 connects 2 pin and the ground of LM324, and R8 connects 2 pin and the output pin 1 of LM324; This output pin 1 connects 10 pin of LM324 through R13; The electric current lo of the output of sampling connects 5 pin of LM324 through resistance R 20, and connects a resistance R 21 between 6 pin and 7 pin, and R22 is connected between 7 pin and 12 pin, and R23 is connected between 12 pin and the ground; R24 is connected between 13 pin and the ground, and R38 and C38 series connection are in the middle of 13 and 14, and R25 also is connected in the middle of 13 and 14; Export 9 pin that 14 pin process resistance R 14 meets LM324, R11 and capacitor C 2 proportion of composing integrating circuit are connected on 9 pin and 8 pin of LM324; The anode of exporting the input of 8 pin process resistance R 12 and light lotus root PC817 joins the minus earth of input; The emitter-base bandgap grading of output is by resistance R 16 ground connection, voltage on the resistance R 16 is received 1 pin of UC3845 then, IP is the voltage on the resistance R 3, this voltage is connected on 3 pin of UC3845 through the low-pass filter circuit of R17 and C26 composition, and connect by resistance R 19 between 4 pin of this chip and 8 pin, and 8 pin are by capacitor C 27 ground connection, 7 pin meet positive supply VC, and 4 pin are by capacitor C 25 ground connection, 6 pin of output amplify by the triode of Q1～Q4, and it amplifies output connects switching tube in the power circuit by a resistance R 35 MG end.And R34 is the bleed off resistance of grid, is connected on MG and MS end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03276727 CN2662529Y (en) | 2003-08-26 | 2003-08-26 | A positively exciting constant current source |
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| CN 03276727 CN2662529Y (en) | 2003-08-26 | 2003-08-26 | A positively exciting constant current source |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100405833C (en) * | 2006-06-01 | 2008-07-23 | 南京Lg同创彩色显示***有限责任公司 | Compensation loop for eliminating switch frequency change to generate electromagnetic interference phenomenon |
| CN100454732C (en) * | 2006-05-23 | 2009-01-21 | 广州电器科学研究院 | High accuracy high power constant current source and its realizing method |
| CN102104340A (en) * | 2009-12-18 | 2011-06-22 | 上海仪器仪表研究所 | High-precision direct current power supply device adopting pulse width modulation |
| CN102882366A (en) * | 2012-09-06 | 2013-01-16 | 海能达通信股份有限公司 | Ripple power supply device and method for providing direct-current voltage with ripples |
| CN103715881A (en) * | 2012-10-09 | 2014-04-09 | 中兴通讯股份有限公司 | Output method, apparatus and control circuit for DC switch power supply |
| CN103792452A (en) * | 2014-01-29 | 2014-05-14 | 重庆长安汽车股份有限公司 | Superimposed alternating voltage test tester for automobile low-voltage electric appliance |
| CN103872883A (en) * | 2014-04-15 | 2014-06-18 | 武汉中原电子集团有限公司 | Voltage limiting and current limiting control device for flyback power supply |
| CN106771542A (en) * | 2016-12-29 | 2017-05-31 | 深圳市科陆电子科技股份有限公司 | A kind of battery voltage acquisition calibrates circuit |
| CN112965563A (en) * | 2021-01-15 | 2021-06-15 | 惠州三华工业有限公司 | Two-stage constant current circuit with time delay and drive control method thereof |
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2003
- 2003-08-26 CN CN 03276727 patent/CN2662529Y/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100454732C (en) * | 2006-05-23 | 2009-01-21 | 广州电器科学研究院 | High accuracy high power constant current source and its realizing method |
| CN100405833C (en) * | 2006-06-01 | 2008-07-23 | 南京Lg同创彩色显示***有限责任公司 | Compensation loop for eliminating switch frequency change to generate electromagnetic interference phenomenon |
| CN102104340A (en) * | 2009-12-18 | 2011-06-22 | 上海仪器仪表研究所 | High-precision direct current power supply device adopting pulse width modulation |
| CN102104340B (en) * | 2009-12-18 | 2013-03-20 | 上海仪器仪表研究所 | High-precision direct current power supply device adopting pulse width modulation |
| CN102882366B (en) * | 2012-09-06 | 2015-06-17 | 海能达通信股份有限公司 | Ripple power supply device and method for providing direct-current voltage with ripples |
| CN102882366A (en) * | 2012-09-06 | 2013-01-16 | 海能达通信股份有限公司 | Ripple power supply device and method for providing direct-current voltage with ripples |
| CN103715881A (en) * | 2012-10-09 | 2014-04-09 | 中兴通讯股份有限公司 | Output method, apparatus and control circuit for DC switch power supply |
| CN103792452A (en) * | 2014-01-29 | 2014-05-14 | 重庆长安汽车股份有限公司 | Superimposed alternating voltage test tester for automobile low-voltage electric appliance |
| CN103872883A (en) * | 2014-04-15 | 2014-06-18 | 武汉中原电子集团有限公司 | Voltage limiting and current limiting control device for flyback power supply |
| CN103872883B (en) * | 2014-04-15 | 2016-03-02 | 武汉中原电子集团有限公司 | A kind of pressure-limit current-limit control device of flyback power supply |
| CN106771542A (en) * | 2016-12-29 | 2017-05-31 | 深圳市科陆电子科技股份有限公司 | A kind of battery voltage acquisition calibrates circuit |
| CN106771542B (en) * | 2016-12-29 | 2019-08-13 | 深圳市科陆电子科技股份有限公司 | A kind of battery voltage acquisition calibration circuit |
| CN112965563A (en) * | 2021-01-15 | 2021-06-15 | 惠州三华工业有限公司 | Two-stage constant current circuit with time delay and drive control method thereof |
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Granted publication date: 20041208 Termination date: 20100826 |