CN103687192A - Switch power supply device - Google Patents
Switch power supply device Download PDFInfo
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- CN103687192A CN103687192A CN201310421850.4A CN201310421850A CN103687192A CN 103687192 A CN103687192 A CN 103687192A CN 201310421850 A CN201310421850 A CN 201310421850A CN 103687192 A CN103687192 A CN 103687192A
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Abstract
The invention provides a switch power supply device which can enable the current of loads to be constant even if the voltage of the load changes. A correction unit (valley bottom detection circuit 30) is used to detect the changes of the voltage of the loads (LED 21, 22). The opportune moment that a control unit (control circuit 1) enables a switch element Q1 to be conducted is corrected based on the detected changes of the voltage of the loads (LED 21, 22). Therefore, even if the voltage of the load (LED 21, 22) changes, the average current (average forward current ILED (avg)) of the loads (LED 21, 22) can be enabled to be constant.
Description
Technical field
The present invention relates to such as making LED(light-emitting diode) etc. the switching power unit of light source bright light.
Background technology
In the past, made LED(light-emitting diode) etc. light source bright light in the situation that, for high efficiency, in most cases use the switching power unit of constant-current type.
As such switching power unit, following LED lamp-enlightened device has for example been proposed in patent documentation 1, in this LED lamp-enlightened device, by full-wave rectifier, the electric current from commercial ac power source is carried out to full-wave rectification, from the 1st less capacitor of capacity, to switch power circuit part, applying is substantially the pulsating voltage of current waveform in full-wave rectifier, by the 2nd capacitor, make the pulse voltage of the switch based on switching power circuit portion level and smooth, be applied to LED illuminating part.
Patent documentation 1: TOHKEMY 2009-134945 communique
In above-mentioned patent documentation 1, input current from commercial ac power source becomes the waveform almost flowing through in all regions obtaining after the paddy portion of having removed all-wave, voltage after level and smooth by the 2nd capacitor is applied to LED illuminating part, can, when reducing the harmonic components of input current, obtain the light equal with the situation of carrying out bright light by direct current smooth voltage and export thus.
In addition,, in such LED lamp-enlightened device, while there is the variation in voltage as the LED as load, the brightness of LED is the situation of change also.
With reference to Fig. 9 and Figure 10, such phenomenon is described.At this, Fig. 9 illustrates for making the figure of an example of the switching power unit of LED bright light, and Figure 10 is the figure that this action waveforms is shown.
In addition, in Figure 10, the I shown in (a)
lEDit is the electric current flowing through in the LED of Fig. 9.V shown in this figure (b)
rEFit is the reference voltage V of Fig. 9
rEF.V shown in this figure (c)
sENthe detection voltage of the SEN terminal of Fig. 9.V shown in this figure (d)
oUTvariation in voltage in the OUT terminal of Fig. 9 is shown.(e) of this figure illustrates the switch element Q of Fig. 9
1conduction and cut-off.
First, in Fig. 9, after the Continuity signal by from control circuit 1 is connected switch element (MOSFET) Q1, current flowing I on the path of supply voltage (direct current) V1 → LED → inductor L1 → switch element Q1 → current sense resistor R1
on.
By current flowing I in current sense resistor R1
on, in SEN terminal, produce and electric current I
onthe detection voltage V being directly proportional
sEN.By comparator 2, will detect voltage V
sENwith outside reference voltage V
rEFcompare, at voltage, become V
sEN> V
rEFthe moment, control circuit 1 disconnects switch element Q1.
Now, due to the energy of putting aside in inductor L1, in LED, current flowing I on the path of inductor L1 → diode D1 → LED
off.Then, certain t deadline setting at the electric capacity through by control circuit 1 and capacitor C1
offafter, control circuit 1 makes switch element Q1 connect again.
In such switching power unit, can control by simple circuit structure, components number is less, is therefore applicable to require the purposes of narrower erection space.
But, in such switching power unit, as the voltage V of LED
lEDduring change, also change of the brightness of LED.
With reference to Figure 11, this phenomenon is described.That is, electric current I during switch element Q1 conducting
onpeak I
peakby reference voltage V
rEFdetermine with current sense resistor R1, be not therefore substantially subject to the impact of the change of LED voltage.Electric current I when in addition, switch element Q1 ends
offslope di/dt by the inductance of LED voltage and inductor L1, determined, deadline t
offaccording to the capacity of control circuit 1 and capacitor C1, be set to fixing.In addition the electric current I when cut-off,
offslope di/dt while changing, to electric current I
offthe time becoming till 0 changes.
Therefore, as shown in the drawing, when LED variation in voltage, due to the variation of the current waveform between the off period, the mean forward current I of LED
lED(
avg) change.In this situation, because the light beam of LED is directly proportional to forward current, therefore as mean forward current I
lED(
avg) while changing, the brightness of LED also changes.
In addition, the change of known LED voltage is because temperature and manufacture deviation produce.Therefore, due to these main cause, even if wish to develop the voltage change as the LED of load, the forward current of LED, be, the mean forward current I of LED
lED(
avg) also constant device still.
Summary of the invention
The present invention completes in view of such situation just, even if its object is to provide a kind of voltage change of load, also can make the constant switching power unit of average current of load.
Switching power unit of the present invention, it provides constant current to load, and this switching power unit is characterised in that to have: power supply circuit, it offers described load by the electric power from power supply; ON-OFF control circuit, it controls the supply from the electric power of this power supply circuit by switch motion; And correcting unit, it proofreaies and correct the switch motion of this ON-OFF control circuit, and described ON-OFF control circuit has: switch element, it carries out described switch motion; Voltage detection unit, it detects voltage according to the electric current that flows through described load; And control unit, it ends described switch element when the voltage being detected by this voltage detection unit surpasses reference voltage, after the deadline through certain, make described switch element conducting, described correcting unit detects the variation in voltage of described load, the variation in voltage of the described load detecting according to this, proofreaies and correct the opportunity that described control unit makes described switch element conducting.
In addition, switching power unit is characterised in that, described power supply circuit has: inductor, and itself and described load are connected in series; And diode, another distolateral connection of its anode-side and this inductor, and cathode side is connected with DC power supply, described correcting unit is the lowest point testing circuit, this the lowest point testing circuit detects the lowest point point that becomes the vibration of described diode after 0 and the voltage between described inductor at the electric current that flows through described inductor, and so that the mode of the lowest point point place's conducting that described switch element detects at this proofread and correct.
In addition, switching power unit is characterised in that, described control unit has voltage and is taken into terminal, and this voltage is taken into terminal and is taken into and illustrates for making the voltage on the opportunity of described switch element conducting, and described the lowest point testing circuit has: the clamper element that the vibration of described voltage is carried out to clamper; And on draw element, its conducting when the trailing edge due to described vibration makes to be applied to the voltage drop of clamper element, is taken into terminal to become for the mode of the voltage of described switch element conducting is drawn on carrying out to described voltage.
In ON-OFF control circuit of the present invention, by correcting unit, detect the variation in voltage of load, the variation in voltage of the load detecting according to this, proofreaies and correct the opportunity that control unit makes switch element conducting.
According to switching power unit of the present invention, by correcting unit, detect the variation in voltage of load, the variation in voltage of the load detecting according to this, proofreaies and correct the opportunity that control unit makes switch element conducting, even if therefore the variation in voltage of load, also can make the average current of load constant.
Accompanying drawing explanation
Fig. 1 is the figure that an execution mode of switching power unit of the present invention is shown.
Fig. 2 is the figure for the action of the switching power unit of key diagram 1.
Fig. 3 is the figure for the action of the lowest point testing circuit of the switching power unit of key diagram 1.
Fig. 4 is the figure for the action of the lowest point testing circuit of the switching power unit of key diagram 1, (a) of this figure illustrates by the lowest point testing circuit the movement oscillogram of the situation of aliging with the lowest point point the opportunity of the connection of switch element, the movement oscillogram that (b) of this figure obtains after the time scale of this Fig. 4 (a) is amplified to 10 times (wherein, the moment shown in arrow e, later voltage waveform was changed to sinuous part, was the movement oscillogram that the situation of not alignd the opportunity of the connection of switch element Q1 with the lowest point point is shown.）。
Fig. 5 is the figure for the action of the lowest point testing circuit of the switching power unit of key diagram 1, and is LED electric current to be shown for the figure of the experimental result (load regulation) of LED voltage.
Fig. 6 is other the figure of example illustrating in the situation of structure of the lowest point testing circuit that has changed Fig. 1.
Fig. 7 be illustrate in the situation of structure of the lowest point testing circuit that has changed Fig. 1 other the figure of example.
Fig. 8 be illustrate in the situation of structure of the lowest point testing circuit that has changed Fig. 1 other the figure of example.
Fig. 9 be illustrate in the past for making the figure of an example of the switching power unit of LED bright light.
Figure 10 is the figure that the action waveforms in the switching power unit of Fig. 9 is shown.
Figure 11 is the figure that the action waveforms in the switching power unit of Fig. 9 is shown.
Label declaration
1: control circuit
2: comparator
3:OUT terminal
4:SEN terminal
5:REF terminal
6:PWM terminal
10: ON-OFF control circuit
11: schmitt inverter
12: NAND gate
13: minimum circuit deadline
14: with door
15: maximum circuit deadline
16: inverter
20: power supply circuit
21、22：LED
30: the lowest point testing circuit
C1, C2: capacitor
D1: diode
Q1: switch element (MOSFET)
Q2: switch element (transistor)
Q3: switch element (P type MOS)
R1: current sense resistor
R2～R5: resistance
V1, V3: supply voltage
ZD1, ZD2: Zener diode
Embodiment
An execution mode of switching power unit of the present invention is described below.In addition, in figure shown below, the part common with Fig. 9 marked to identical label, suitably carry out the explanation of repetition.
First, as shown in Figure 1, switching power unit has ON-OFF control circuit 10, power supply circuit 20 and the lowest point testing circuit 30.
ON-OFF control circuit 10 has control circuit 1, comparator 2 and switch element (MOSFET) Q
1.Control circuit 1 carries out for making the PWM(pulse width modulation of LED bright light: pulse-width modulation) control.
At this, control circuit 1 is connected with the grid of switch element (MOSFET) Q1, the outlet side of comparator 2 and PWM terminal 6.
The drain electrode of switch element Q1 is connected with OUT terminal 3.The source electrode of switch element Q1 is connected between the SEN terminal 4 and the negative terminal of comparator 2 being connected with current sense resistor R1.
The plus end of comparator 2 be connected with reference voltage V
rEFrEF terminal 5 connect.PWM terminal 6 is connected with the lowest point testing circuit 30 with capacitor C1.
The lowest point testing circuit 30 as the correcting unit of ON-OFF control circuit of the present invention has switch element (transistor) Q2.Base stage side at switch element Q2 is connected in series with resistance R 4, R5, capacitor C2.In addition, another of one end of capacitor C2 and above-mentioned inductor L1 is distolateral is connected with the tie point of OUT terminal 3.In addition, on the tie point of resistance R 4 and resistance R 5, be connected with Zener diode ZD2.
The emitter side of switch element Q2 is connected with the anode-side of Zener diode ZD1, via Zener diode ZD1, is connected with supply voltage V3.In addition, the tie point of the cathode side of Zener diode ZD1 and supply voltage V3 is connected with the base stage side of switch element Q2 via resistance R 3.One distolateral connection of the collector electrode side of switch element Q2 and resistance R 2.In addition, another distolateral with above-mentioned PWM terminal 6 of resistance R 2 and distolateral a connection of capacitor C1, another distolateral being grounded of capacitor C1.
Then, with reference to Fig. 2 and Fig. 3, action is described.In addition, the ILED shown in Fig. 2 (a) is the electric current that flows through the LED of Fig. 1.V shown in Fig. 2 (b)
rEFit is the reference voltage V of Fig. 1
rEF.V shown in Fig. 2 (c)
sENthe detection voltage in the SEN terminal 4 of Fig. 1.V shown in Fig. 2 (d)
oUTvariation in voltage in the OUT terminal 3 of Fig. 1 is shown.(e) of Fig. 2 illustrates the conduction and cut-off of the switch element Q1 of Fig. 1.
First, as shown in Fig. 2 (e), after the Continuity signal by from control circuit 1 is connected switch element (MOSFET) Q1, on the path of supply voltage V1 → LED21,22 → inductor L1 → switch element Q1 → current sense resistor R1, flow through the forward current I shown in (a) of Fig. 2
lED(electric current I
on).
Electric current I
oncurrent flowing detects resistance R 1, thus, in SEN terminal 4, produces and electric current I
ondetection voltage V shown in the Fig. 2 being directly proportional (c)
sEN.By comparator 2, will detect voltage V
sENwith the outside reference voltage V shown in (b) of Fig. 2
rEFcompare, at voltage, become V
sEN> V
rEFthe moment, as shown in Fig. 2 (e), control circuit 1 disconnects switch element Q1.
Now, due to the energy of putting aside, in LED21,22, on the path of inductor L1 → diode D1, flow through the forward current I shown in (a) of Fig. 2 in inductor L1
lED(electric current I
off).Then, at certain t deadline through setting according to the capacity of control circuit 1 and capacitor C1
offafter, as shown in Fig. 2 (e), control circuit 1 makes switch element Q1 connect again.
At this, in inductor L1 under the state of current flowing, the voltage V of the OUT terminal 3 shown in Fig. 2 (d)
oUTv1 equates substantially with supply voltage.In addition, if at certain t deadline through setting according to the capacity of control circuit 1 and capacitor C1
offin the past, the energy regeneration of inductor L1 finished, as shown in the arrow a of Fig. 2 (d), and the voltage V of OUT terminal 3
oUTbecause the stray capacitance of the inductance of inductor L1 and switch element Q1 etc. is vibrated.
Now, in the lowest point testing circuit 30, by the voltage V of OUT terminal 3
oUTtrailing edge differential in capacitor C2 of vibration, by Zener diode ZD2, undertaken after clamper, at the cathode side of Zener diode ZD2, produce from V
zD2change to-V
fwaveform.In addition, V
zD2the reverse voltage (Zener voltage) of Zener diode ZD2, V
fit is the forward voltage of Zener diode ZD2.
When the signal of this waveform being input to after the base stage of switch element Q2, switch element Q2 is connection before the lowest point of the signal of this waveform is tight.Now, due to the connection of switch element Q2, PWM terminal 6 is connected with supply voltage V3 with resistance R 2 via Zener diode ZD1, thus the voltage of PWM terminal 6 by draw, by control circuit 1, switch element Q1 is connected.
At this, as shown in Figure 3, in adjusting the opportunity of connecting, by the value of adjusting resistance R2, can be alignd the opportunity of the connection of switch element Q1 with the lowest point point.In addition, the lowest point point herein refers to, as shown in the arrow a of Fig. 2 (d), from the energy of inductor L1 has been emitted opportunity through moment in 1/4 cycle of harmonic period.
Like this, alignd the opportunity of the connection of switch element Q1 with the lowest point point, according to the change of LED voltage, carry out thus the opportunity of the connection of correcting switch element Q1.In other words, although t deadline of switch element Q1
offaccording to the capacity of control circuit 1 and capacitor C1, be set to constant, but this deadline t
offcan be corrected.
And, alignd the opportunity of the connection of switch element Q1 with the lowest point point, even if thus at LED21,22 voltage V
lEDin the situation that has occurred to change, (the I of Fig. 2 (a) between the off period
oFF) average current substantially constant.
Thus, as shown in Fig. 3 (a), (c), even if in the situation that LED21,22 voltage drop or rising and change has occurred, compare with the situation of the standard shown in (b) of Fig. 3 known, mean forward current I
lED(
avg) be also substantially retained as constantly, so LED21,22 brightness can change.
That is,, as Fig. 3 (a), the in the situation that of LED voltage drop, in the mode postponing on opportunity of the connection of switch element Q1, proofread and correct.In this situation, t deadline of switch element Q1
offelongated.On the other hand, as Fig. 3 (b), in the situation that LED voltage rises, in the mode shifting to an earlier date on opportunity of the connection of switch element Q1, proofread and correct.In this situation, t deadline of switch element Q1
offshorten.
At this, be below by the experimental result in the situation of aliging with the lowest point point the opportunity of the connection of switch element Q1 by the lowest point testing circuit 30 in present embodiment.
That is, (a) of Fig. 4 illustrates by the lowest point testing circuit 30 movement oscillogram of the situation of aliging with the lowest point point the opportunity of the connection of switch element Q1, the movement oscillogram after (b) of Fig. 4 amplifies 10 times by the time scale of Fig. 4 (a).Wherein, the moment shown in arrow e, later voltage waveform was changed to sinuous part, was the movement oscillogram that the situation of not alignd the opportunity of the connection of switch element Q1 with the lowest point point is shown.
When voltage first, as shown in the arrow a of Fig. 4 (a), the known drain electrode that becomes 0, OUT terminal 3(switch element Q1 at LED electric current) becomes the lowest point, the voltage of PWM terminal 6 rises, and carries out the pseudoharmonic vibration of switch element Q1 connection and does.In addition voltage as shown in the arrow b of Fig. 4 (a), the known voltage drop when PWM terminal 6, when switch element Q1 disconnects, the drain electrode of OUT terminal 3(switch element Q1) rises.In addition, known between arrow a-b, flow through the above-mentioned electric current I as LED electric current
on.
When voltage in addition, as shown in arrow c, the known drain electrode at OUT terminal 3(switch element Q1) becomes the lowest point, the voltage of PWM terminal 6 rises, and carries out and above-mentioned same pseudoharmonic vibration is done.In addition, known between arrow b-c, flow through the above-mentioned electric current I as LED electric current
off.That is, known in (a) of Fig. 4, the voltage rising edge of PWM terminal 6 constantly with start to flow through the electric current I as LED electric current
onthe moment between produce skew.In addition, the known voltage drop at PWM terminal 6 along constantly with start to flow through the above-mentioned electric current I as LED electric current
offthe moment between produce skew.
On the other hand, (b) of Fig. 4 of obtaining after time amplification carried out Fig. 4 (a) in observation, as shown in arrow d, when the voltage drain electrode as OUT terminal 3(switch element Q1) starts to decline, due to the stray capacitance of the inductance of the inductor L1 of Fig. 1 and switch element Q1 etc., the drain electrode of OUT terminal 3(switch element Q1) voltage V
oUT(drain voltage) vibrates (harmonic wave).In addition, although known at the moment shown in arrow e, voltage V
oUT(drain voltage) becomes the lowest point, but the voltage at the middle PWM terminal 6 of arrow d-e starts to rise, in the lowest point of the harmonic wave in the moment shown in arrow e (from the energy of above-mentioned inductor L1 has been emitted opportunity through moment of 1/4 week after date of harmonic period), switch element Q1 connects.In addition, known from the moment shown in arrow e, flow through the above-mentioned electric current I as LED electric current
on.
In addition, Fig. 5 illustrates LED electric current for the figure of the experimental result (load regulation) of above-mentioned LED voltage.
As shown in the drawing, to the situation (pseudo-resonance) of aliging with the lowest point point the opportunity of the connection of switch element Q1 being compared with the situation of by the lowest point testing circuit 30, not alignd the opportunity of the connection of switch element Q1 with the lowest point point (circuit conventionally) by the lowest point testing circuit 30, the change of the LED electric current of the known change with respect to LED voltage obtains larger improvement.
Like this, possess in the present embodiment following structure, have: power supply circuit (20), it offers load (LED21,22) by the electric power from power supply (supply voltage V1); ON-OFF control circuit (10), it controls the supply from the electric power of this power supply circuit (20) by switch motion; And correcting unit (the lowest point testing circuit 30), it proofreaies and correct the switch motion of this ON-OFF control circuit (10), and ON-OFF control circuit (10) has: switch element (Q1), it carries out switch motion; Voltage detection unit (SEN terminal 4 and resistance R 1), it detects voltage according to the electric current that flows through load (LED21,22); And control unit (control circuit 1), it surpasses reference voltage (V at the voltage being detected by this voltage detection unit (SEN terminal 4 and resistance R 1)
rEF) time make switch element (Q1) cut-off, after the deadline through certain, make switch element (Q1) conducting, correcting unit (the lowest point testing circuit 30) detects the variation in voltage of load (LED21,22), the variation in voltage of the load detecting according to this (LED21,22), proofreaies and correct the opportunity that control unit (control circuit 1) makes switch element (Q1) conducting.
Particularly, power supply circuit 20 has: inductor L1, and itself and LED21,22 are connected in series; And diode D1, another distolateral connection of its anode-side and this inductor L1, and cathode side is connected with DC power supply (supply voltage V1), the lowest point point of diode D1 when testing circuit 30 sense switch element Q1 in the lowest point switch to conducting from cut-off and the vibration of the voltage between inductor L1, proofreaies and correct the mode of switch element Q1 conducting with the lowest point point detecting at this.
More particularly, control circuit 1 has voltage and is taken into terminal (PWM terminal 6), this voltage is taken into terminal (PWM terminal 6) and is taken into and illustrates for making the voltage on the opportunity of switch element Q1 conducting, the lowest point testing circuit 30 has: clamper element (Zener diode ZD2), and it carries out clamper to the voltage of the lowest point point of the vibration of voltage; And on draw element (switch element Q2), its conducting when the voltage of the lowest point point being carried out to clamper by this clamper element (Zener diode ZD2), is taken into terminal (PWM terminal 6) to become for the mode of the voltage of switch element Q1 conducting is drawn on carrying out to voltage.
By such structure, by correcting unit (the lowest point testing circuit 30), detect the variation in voltage of load (LED21,22), the variation in voltage of the load detecting according to this (LED21,22), correction control unit (control circuit 1) makes the opportunity of switch element (Q1) conducting, therefore, even if the variation in voltage of load (LED21,22), also can make average current (the mean forward current I of load (LED21,22)
lED(
avg)) constant.
In addition, due to the lowest point point of the vibration of the voltage between the switching of the conduction and cut-off of switch element Q1 and diode D1 and inductor L1 is alignd, thereby carry out efficiently the switch motion of switch element Q1, therefore can also expect the low effect that subtracts of noise and switch infringement.
In addition, the lowest point testing circuit 30 is not limited to the structure shown in Fig. 1, can be also following structure.
; example as shown in Figure 6; schmitt inverter 11, inverter 16, switch element (P type MOS) Q3 are set and replace the switch element Q2 of Fig. 1, the anode that detects Zener diode ZD2 by schmitt inverter 11 becomes negative situation, makes switch element (MOSFET) Q3 conducting.
In this situation, also with above-mentioned same, even if LED21,22 variation in voltage also can make LED21,22 mean forward current I
lED(
avg) constant.
In addition, can be also that example as shown in Figure 7, adopts minimum deadline of the circuit 13 that NAND gate 12 and fixing minimum deadline be set to replace the structure of switch element (the P type MOS) Q3 of Fig. 6.
In this situation, owing to being fixed to cut-off by minimum circuit 13 official hours deadline, the OUT terminal 3 that therefore can prevent at Fig. 1 is connected and is shifted to an earlier date singularly when noise is overlapping.That is,, when arriving by minimum deadline during circuit 13 official hour, from minimum deadline of circuit 13 output, be provided for NAND gate 12.
In addition, can be also as shown in Figure 8, to adopt in circuit 15 structure maximum deadline of the outlet side setting of the NAND gate 12 of Fig. 7 and door 14 and regulation maximum deadline.
In this situation, in the situation that can not detect the differential signal of the resonance in OUT terminal 3, switch element Q1 by former state be fixed as cut-off, even if but through certain hour t
off(
max) can not detect in the situation of differential signal, when after by maximum circuit 15 official hours deadline, can make forcibly switch element Q1 conducting.That is,, when reaching by after maximum deadline circuit 15 official hours, from maximum deadline of circuit 15 output, be provided for and door 14.
Claims (3)
1. a switching power unit, it provides constant current to load, and this switching power unit is characterised in that to have:
Power supply circuit, it offers described load by the electric power from power supply;
ON-OFF control circuit, it controls the supply from the electric power of this power supply circuit by switch motion; And correcting unit, it proofreaies and correct the switch motion of this ON-OFF control circuit,
Described ON-OFF control circuit has:
Switch element, it carries out described switch motion;
Voltage detection unit, it detects voltage according to the electric current that flows through described load; And
Control unit, it ends described switch element when the voltage being detected by this voltage detection unit surpasses reference voltage, makes described switch element conducting after the deadline through certain,
Described correcting unit detects the variation in voltage of described load, and the variation in voltage of the described load detecting according to this is proofreaied and correct the opportunity that described control unit makes described switch element conducting.
2. switching power unit according to claim 1, is characterized in that,
Described power supply circuit has:
Inductor, itself and described load are connected in series; And
Diode, another distolateral connection of its anode-side and this inductor, and cathode side is connected with DC power supply,
Described correcting unit is the lowest point testing circuit, this the lowest point testing circuit detects the lowest point point that becomes the vibration of described diode after 0 and the voltage between described inductor at the electric current that flows through described inductor, and so that the mode of the lowest point point place's conducting that described switch element detects at this proofread and correct.
3. switching power unit according to claim 2, is characterized in that,
Described control unit has voltage and is taken into terminal, and this voltage is taken into terminal and is taken into and illustrates for making the voltage on the opportunity of described switch element conducting,
Described the lowest point testing circuit has:
Clamper element, it carries out clamper to the vibration of described voltage; And
On draw element, its conducting when the trailing edge due to described vibration makes to be applied to the voltage drop of clamper element, is taken into terminal so that its voltage becomes for the mode of the voltage of described switch element conducting is drawn on carrying out to described voltage.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012-208151 | 2012-09-21 | ||
| JPJP2012-208151 | 2012-09-21 | ||
| JP2012208151A JP2014064393A (en) | 2012-09-21 | 2012-09-21 | Switching power supply device |
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| Publication Number | Publication Date |
|---|---|
| CN103687192A true CN103687192A (en) | 2014-03-26 |
| CN103687192B CN103687192B (en) | 2016-08-17 |
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| CN201310421850.4A Expired - Fee Related CN103687192B (en) | 2012-09-21 | 2013-09-16 | Switching power unit |
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| CN (1) | CN103687192B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110247553A (en) * | 2018-03-09 | 2019-09-17 | 台达电子工业股份有限公司 | Converter and its control method |
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| KR102417316B1 (en) * | 2015-06-05 | 2022-07-05 | 주식회사 엘엑스세미콘 | Switching power supply apparatus and contorl method thereof |
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| JP5508095B2 (en) * | 2010-03-30 | 2014-05-28 | パナソニック株式会社 | Lighting device, lighting fixture using the same, and lighting system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012128245A1 (en) * | 2011-03-18 | 2012-09-27 | 株式会社ソディック | Straight tube led illumination lamp |
| CN102186292A (en) * | 2011-04-30 | 2011-09-14 | 杭州电子科技大学 | Primary edge current reference generating circuit and method for high power factor constant-current switch power supply |
| CN202335020U (en) * | 2011-11-29 | 2012-07-11 | 叶军 | Light-emitting diode (LED) driving circuit and LED driving chip |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110247553A (en) * | 2018-03-09 | 2019-09-17 | 台达电子工业股份有限公司 | Converter and its control method |
| US10644606B2 (en) | 2018-03-09 | 2020-05-05 | Delta Electronics, Inc. | Converter and control method thereof |
| CN110247553B (en) * | 2018-03-09 | 2020-11-06 | 台达电子工业股份有限公司 | Converter and control method thereof |
| US10938312B2 (en) | 2018-03-09 | 2021-03-02 | Delta Electronics, Inc. | Converter and control method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103687192B (en) | 2016-08-17 |
| JP2014064393A (en) | 2014-04-10 |
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