CN104955211A - Lighting circuit, device and system - Google Patents

Abstract

The invention provides a lighting circuit, device and system; the lighting circuit comprises a power conversion portion, a current adjusting portion and a control portion; the power conversion portion is connected with a light dimmer through a supply path, and connected with a light load; an AC voltage with phase control and supplied by the light dimmer is converted into DC voltage, and the DC voltage is supplied to the light load; the current adjusting portion switches part of current passing the power supply path between a conduction state and non conduction state; the control portion conducts the current adjusting portion when the AC voltage is detected to be smaller than a first threshold voltage; when the detection voltage is above the first threshold voltage, the current adjusting portion is in non-conduction state; when the detection voltage changes from a minimum value to the maximum value, the current adjusting portion time sequence delay is above a second threshold voltage of the detection voltage; the lighting circuit is stable in motion.

Description

Lamp circuit, lighting device and illuminator

Technical field

The present invention relates to a kind of lamp circuit, lighting device and illuminator (system).

Background technology

Have following lamp circuit, it is connected to the dimmer of phase control mode, the alternating electromotive force supplied is converted to direct current power and is supplied to lighting load from dimmer, makes lighting load light thus.Have following lighting device, it comprises lamp circuit and lighting load.Have following illuminator, it comprises lighting device and dimmer.In such lamp circuit, lighting device and illuminator, expect having stable behavior.

[background technology document]

[patent documentation]

[patent documentation 1] Japanese Patent Laid-Open 2009-232625 publication

[patent documentation 2] Japanese Patent Laid-Open 2012-034569 publication

Summary of the invention

[problem of invention for solving]

The object of the present invention is to provide a kind of lamp circuit of having stable behavior, lighting device and illuminator.

[solving the means of problem]

The invention provides a kind of lamp circuit, it comprises power conversion unit, electric current adjustment part and control part.Described power conversion unit is connected to dimmer via power supply feed path, and is connected to lighting load, and by the carrying out supplied from described dimmer, the alternating voltage of phase control is converted to direct voltage and is supplied to described lighting load.Described electric current adjustment part has the individual path being connected to described power supply feed path, and switched conductive state and nonconducting state, thus the electric current of described power supply feed path is flow through in adjustment, described conducting state instigates a part for the electric current flowing through described power supply feed path to flow through described individual path, and described nonconducting state refers to and do not make electric current flow through described individual path.Described control part is when the detection voltage of described alternating voltage is less than first threshold voltage, described electric current adjustment part is made to be described conducting state, when described detection voltage becomes more than described first threshold voltage, described electric current adjustment part is made to be described nonconducting state, and be changed in the scope of maximum at described detection voltage from minimum value, by make described electric current adjustment part be sequential time delay to the described detection voltage of described nonconducting state become higher than described first threshold voltage Second Threshold voltage more than.

The present invention also provides a kind of lighting device, comprising: lighting load; And described lamp circuit, to described lighting load supply electric power.

The present invention also provides a kind of illuminator, comprising: described lighting device; And dimmer, the alternating voltage carrying out phase control is supplied to described lighting device.

[effect of invention]

According to the embodiment of the present invention, a kind of lamp circuit of having stable behavior, lighting device and illuminator can be provided.

Accompanying drawing explanation

Fig. 1 is the block diagram of the lighting device schematically showing execution mode.

Fig. 2 is the circuit diagram of the lamp circuit schematically showing execution mode.

Fig. 3 (a) and Fig. 3 (b) is the curve chart of an example of the action of the control part schematically showing execution mode.

Fig. 4 (a) and Fig. 4 (b) is the curve chart of the example schematically showing alternating voltage and control signal.

Fig. 5 (a) and Fig. 5 (b) is the curve chart of another example schematically showing alternating voltage and control signal.

Fig. 6 is the circuit diagram of another lamp circuit schematically showing execution mode.

Fig. 7 (a) and Fig. 7 (b) is the curve chart of another example schematically showing alternating voltage and control signal.

[explanation of symbol]

2: AC power

3: dimmer

3s, 78: switch element

4,5,30a, 30b: input terminal

6: terminal

7,8: lead-out terminal

10: lighting device

12: lighting load

14,114: lamp circuit

16: lighting source

20: power conversion unit

20a:AC-DC transducer

20b:DC-DC transducer

21a: the first power supply feed path

21b: second source feed path

22: control part

23: control power supply portion

24: electric current adjustment part

25: feedback circuit

27: wiring part

27a, 27b: distribution

28: individual path

30: rectification circuit

30c: high potential terminal

30d: electronegative potential terminal

32: smmothing capacitor

34,43: inductor

36: filtering capacitor

40: output element

41: current controling element

42,61 ~ 63: rectifier cell

44: feedback winding

45: coupling capacitor

46,47: divider resistance

48: output capacitor

49: bias resistance

50,70,100: semiconductor element

64,71,72,75,76,82,84 ~ 86,88,90,91,101,102,104: resistance

65: charge storage cell

66,83,87,92,103: capacitor

67: adjuster

68: Zener diode

80: differential amplifier circuit

81: operational amplifier

CGS: control signal

DMS: dim signal

LS: illuminator

S11, S12, S13: signal

Ton: conducting is interval

Toff: block interval

VC: the voltage of smmothing capacitor

VCT: alternating voltage

VDC1: the first direct voltage

VDC2: the second direct voltage

VDD: driving voltage

Vdet: detect voltage

VIN: supply voltage

Vth1: first threshold voltage

Vth2: Second Threshold voltage

Embodiment

Below, one side illustrates each execution mode with reference to accompanying drawing one side.

In addition, accompanying drawing is schematic or conceptual figure, and the thickness of each several part may not be identical with actual conditions with size ratio between the relation of width, part etc.In addition, even if when representing same section, sometimes also represent mutual size or ratio with reference to the accompanying drawings and differently.

In addition, in specification of the present invention and each figure, also suitably detailed description is omitted to the element annotation prosign identical with the key element described in the figure proposed.

Fig. 1 is the block diagram of the lighting device schematically showing execution mode.

As shown in Figure 1, illuminator LS comprises lighting device 10 and dimmer 3.Lighting device 10 comprises lighting load 12 and lamp circuit 14.Lighting load 12 such as has the lighting sources 16 such as light-emitting diode (Light-emitting diode:LED).Lighting source 16 such as also can be Organic Light Emitting Diode (Organic light-emitting diode:OLED) etc.For lighting source 16, such as, use and there is the light-emitting component that voltage falls in forward.Lighting load 12 by the applying of the output voltage from lamp circuit 14 and the supply of output current, lighting source 16 is lighted.The value of output voltage and output current specifies according to lighting source 16.

Lamp circuit 14 is connected with AC power 2 and dimmer 3.In addition, in the description of the present invention, so-called " connection " means to be electrically connected, and also comprises situation about physically not connecting or situation about connecting via other key elements.In addition, also comprise in " connection " via transformer (transformer) etc. and the situation of magnetic couplings.

AC power 2 is such as source power supply.Dimmer 3 is connected to AC power 2.Dimmer 3 produces the alternating voltage VCT having carried out the angle of flow and controlled from the supply voltage VIN of the interchange of AC power 2.Dimmer 3 is connected in series between an input terminal 4 of a pair power line (power line) of supply line voltage VIN, terminal 6.That is, dimmer 3 is dimmers of so-called TW two wire.Dimmer 3 is not limited thereto, and may also be such as three-wire type or four-wire type etc.

Lamp circuit 14 has pair of input terminals 4, input terminal 5 and pair of output 7, lead-out terminal 8.Lamp circuit 14 via each input terminal 4, input terminal 5 and be connected to AC power 2 and dimmer 3, and via each lead-out terminal 7, lead-out terminal 8 and be connected to lighting load 12.

Lamp circuit 14 is by the alternating voltage supplied from dimmer 3 VCT being converted to direct voltage and exporting lighting load 12 to, and lighting source 16 is lighted.In addition, lamp circuit 14 and the light modulation having carried out alternating voltage VCT that the angle of flow controls and synchronously carry out lighting source 16.In addition, dimmer 3 optionally arranges, and can omit.When not arranging dimmer 3, the supply voltage VIN of AC power 2 is supplied to lamp circuit 14.

For dimmer 3, use the dimmer of phase control (forward position (leading edge)) mode.Dimmer 3 controls the phase place of conducting during becoming maximum from the zero crossing (zero cross) of alternating voltage to the absolute value of alternating voltage.That is, in this embodiment, alternating voltage VCT has carried out the alternating voltage of phase control.The alternating voltage VCT having carried out phase control is supplied to lamp circuit 14 by dimmer 3.

Dimmer 3 is the dimmer corresponding to incandescent lamp bulb etc.Dimmer 3 comprises switch (switching) element 3s.Dimmer 3 disconnects (off) by the connection (on) of switch element 3s and switches the conducting interval of phase control and blocking-up interval.Such as when making switch element 3s be on-state, alternating voltage VCT becomes conducting interval, and when making switch element 3s be off state, it is interval that alternating voltage VCT becomes blocking-up.For switch element 3s, such as, use triac (triac) etc.

Dimmer 3 such as also comprises degree of dimming configuration part and variable resistor.Degree of dimming configuration part is such as slide switch (slide switch) or dial switch (dial switch) etc.Degree of dimming configuration part is connected to variable resistor.Degree of dimming configuration part is operation according to user etc. and makes variable-resistance resistance change.

Dimmer 3 makes electric current temporarily flow through the control terminal of switch element 3s.That is, dimmer 3 makes pulse current (pulse current) flow through the control terminal of switch element 3s.Switch element 3s corresponds to the supply of pulse current and becomes on-state, becomes off-state when the zero crossing of alternating voltage VCT.Switch element 3s is after becoming on-state, and no matter the current potential of control terminal how, becomes off-state when the potential difference all between main terminal becomes below setting.The generation of pulse current such as uses diac (trigger diode).Dimmer 3 is timing variations pulse current being flowed according to variable-resistance resistance value.Thus, supply voltage VIN is converted to alternating voltage VCT by dimmer 3.

Lamp circuit 14 comprises power conversion unit 20, first power supply feed path 21a, control part 22, control power supply portion 23, electric current adjustment part 24 and feedback (feedback) circuit 25.First power supply feed path 21a is connected to pair of input terminals 4, input terminal 5.

Power conversion unit 20 comprises AC-DC (Alternating Current-Alternating Current, AC-AC) transducer (converter) 20a, DC-to-DC (Direct Current-Direct Current, DC-DC) transducer 20b and second source feed path 21b.AC-DC converter 20a is connected to the first power supply feed path 21a.AC-DC converter 20a is via the first power supply feed path 21a and each input terminal 4, input terminal 5 and be connected to dimmer 3.The alternating voltage VCT supplied via the first power supply feed path 21a is converted to the first direct voltage VDC1 by AC-DC converter 20a.

Dc-dc 20b is connected with AC-DC converter 20a via second source feed path 21b.The the first direct voltage VDC1 supplied from second source feed path 21b is converted to the second direct voltage VDC2 of the magnitude of voltage of the regulation corresponding to lighting load 12 and is supplied to lighting load 12 by dc-dc 20b.The absolute value of the second direct voltage VDC2 is different from the absolute value of the first direct voltage VDC1.The absolute value of the second direct voltage VDC2 is such as lower than the absolute value of the first direct voltage VDC1.In this embodiment, dc-dc 20b is buck converter.By supplying the second direct voltage VDC2, and the lighting source 16 of lighting load 12 is lighted.So, power conversion unit 20 is connected to dimmer 3 and lighting load 12, and by the carrying out supplied from dimmer 3, the alternating electromotive force of phase control is converted to direct current power and is supplied to lighting load 12.

Control power supply portion 23 has the wiring part 27 being connected to the first power supply feed path 21a.Wiring part 27 comprises the distribution 27a being connected to the input terminal 4 and distribution 27b being connected to input terminal 5.The alternating voltage VCT inputted via wiring part 27 is converted to the driving voltage VDD of the direct current corresponding to control part 22 by control power supply portion 23, and this driving voltage VDD is supplied to control part 22.Wiring part 27 such as also can be connected to second source feed path 21b.

Electric current adjustment part 24 has the individual path 28 being connected to the first power supply feed path 21a, changeable make a part for the electric current flowing through the first power supply feed path 21a flow through individual path 28 conducting state and electric current do not flow through the nonconducting state of individual path 28.Thus, electric current adjustment part 24 such as adjusts the electric current flowing through the first power supply feed path 21a.In this embodiment, the individual path 28 of electric current adjustment part 24 is connected to the first power supply feed path 21a via control power supply portion 23.Individual path 28 also can not be connected directly between the first power supply feed path 21a via control power supply portion 23.In addition, nonconducting state also comprises situation action being flow through to individual path 28 without the small electric current affected.Nonconducting state such as flowing through the little state of the electric current of individual path 28 compared with conducting state.Individual path 28 such as also can be connected to second source feed path 21b.

Control part 22 detects the angle of flow of alternating voltage VCT.Control part 22 produces the dim signal DMS corresponding to the detected angle of flow, and this dim signal DMS is inputed to feedback circuit 25.Thus, control part 22 controls to utilize the electric power of power conversion unit 20 to change according to the detected angle of flow.That is, control part 22 carries out light modulation according to the detected angle of flow to lighting load 12.

In addition, this control signal CGS by producing control signal CGS according to the detected angle of flow, and is inputed to electric current adjustment part 24 by control part 22, and controls the switching between the conducting state of electric current adjustment part 24 and nonconducting state.So, control part 22 by controlling electric current adjustment part 24 and feedback circuit 25 according to the detected angle of flow, and with the angle of flow control synchronization of dimmer 3 light modulation is carried out to lighting source 16.For control part 22, such as, use microprocessor (microprocessor).

Feedback circuit 25 is connected to the lead-out terminal 8 of the low potential side of lamp circuit 14.That is, feedback circuit 25 is connected to the end of the low potential side of lighting load 12.Feedback circuit 25 detects the electric current flowing through lighting load 12 (lighting source 16).Feedback circuit 25 is dim signal DMS based on inputting from control part 22 and detected electric current, and FEEDBACK CONTROL dc-dc 20b.

Feedback circuit 25 is based on dim signal DMS and detected electric current, and the electric current of control flow check over-illumination load 12.Feedback circuit 25 such as will flow through the Current Control of lighting load 12 for fixing in fact.Thus, such as the brightness of lighting load 12 can be remained fixing in fact.Overcurrent such as can be suppressed to flow through lighting load 12.

Fig. 2 is the circuit diagram of the lamp circuit schematically showing execution mode.

As shown in Figure 2, AC-DC converter 20a has rectification circuit 30, smmothing capacitor (smoothing condenser) 32, inductor (inductor) 34 and filtering capacitor (filter condenser) 36.

Rectification circuit 30 is such as diode bridge (diode bridge).The input terminal 30a of rectification circuit 30, input terminal 30b are connected to pair of input terminals 4, input terminal 5.For input terminal 30a, the input terminal 30b of rectification circuit 30, via dimmer 3, the alternating voltage VCT of phase control or inverse phase control has been carried out in input.Rectification circuit 30 such as by alternating voltage VCT full-wave rectification, the pulsating voltage produce full-wave rectification between high potential terminal 30c and electronegative potential terminal 30d after.Alternating voltage VCT is converted to commutating voltage by rectification circuit 30.Commutating voltage is such as pulsating voltage.

Smmothing capacitor 32 is connected between the high potential terminal 30c of rectification circuit 30 and electronegative potential terminal 30d.Smmothing capacitor 32 makes the pulsating voltage smoothing having been carried out rectification by rectification circuit 30.Thus, the first direct voltage VDC1 is presented at the two ends of smmothing capacitor 32.

Inductor 34 is connected in series in input terminal 4.Inductor 34 is such as connected in series in the first power supply feed path 21a.Filtering capacitor 36 is connected between input terminal 4 and input terminal 5.Filtering capacitor 36 is such as connected in parallel in the first power supply feed path 21a.Noise (noise) contained in alternating voltage VCT is such as removed by inductor 34 and filtering capacitor 36.

Dc-dc 20b is connected to the two ends of smmothing capacitor 32.Thus, the first direct voltage VDC1 is input to dc-dc 20b.First direct voltage VDC1 is converted to the second different direct voltage VDC2 of absolute value by dc-dc 20b, and this second direct voltage VDC2 is exported to lead-out terminal 7, the lead-out terminal 8 of lamp circuit 14.Lighting load 12 is connected to lead-out terminal 7, lead-out terminal 8.Lighting load 12 makes lighting source 16 light by the second direct voltage VDC2 supplied from lamp circuit 14.

Dc-dc 20b such as has output element 40, current controling element 41, rectifier cell 42, inductor 43, feedback winding (feedback winding) (driving element) 44 of driver output element 40, coupling capacitor 45, divider resistance 46, divider resistance 47, output capacitor 48 and bias voltage (bias) resistance 49.

Output element 40 and current controling element 41 are such as field-effect transistor (FET), and be such as High Electron Mobility Transistor (High Electron Mobility Transistor:HEMT), and be the element of normal conducting (normally on) type.

The drain electrode (drain) of current controling element 41 is electrically connected at second source feed path 21b via output element 40.The source electrode (source) of current controling element 41 is electrically connected at lighting load 12.The grid of current controling element 41 is used to the electrode of the electric current between the Drain-Source of control flow check excess current control element 41.

Current controling element 41 has the first state and the second state, and described first state refers to that electric current flows through between drain electrode and source electrode, described second state refer to flow through compared with the first state drain and electric current between source electrode little.First state is such as on-state, and the second state is such as off state.First state is not limited to on-state.Second state is not limited to off-state.First state can be the relatively large free position of the electric current of flowing compared with the second state.Second state can be the relatively little free position of the electric current of flowing compared with the first state.

In the current controling element 41 of the element as normally-ON type, by making the current potential of current potential lower than source electrode of grid, and be the second state from the first state variation.Such as current controling element 41 by make the current potential of grid relative to the current potential relativity of source electrode for negative potential, and be changed to off-state from on-state.

The drain electrode of output element 40 is connected to the high potential terminal 30c of rectification circuit 30.The source electrode of output element 40 is connected to the drain electrode of current controling element 41.The grid of output element 40 is connected to one end of feedback winding 44 via coupling capacitor 45.

The source electrode of current controling element 41 is connected to one end of inductor 43 and the other end of feedback winding 44.For the grid of current controling element 41, input the voltage utilizing divider resistance 46, divider resistance 47 the source potential dividing potential drop of current controling element 41 to be obtained.Protection diode is respectively connected at the grid of output element 40 and the grid of current controling element 41.

Bias resistance 49 is connected between the drain electrode of output element 40 and the source electrode of current controling element 41, supplies direct voltage to divider resistance 46, divider resistance 47.Its result, the current potential lower than the current potential of source electrode to the grid supply of current controling element 41.

Inductor 43 and feedback winding 44, with following polarity magnetic couplings, namely when the electric current that the flowing from one end of inductor 43 to the other end increases, supply the voltage of positive polarity to the grid of output element 40.

Rectifier cell 42 is set to forward by from electronegative potential terminal 30d to the direction of current controling element 41, and be connected between the source electrode of current controling element 41 and the electronegative potential terminal 30d of rectification circuit 30.

In this embodiment, semiconductor element 50 is set between rectifier cell 42 and the source electrode of current controling element 41.For semiconductor element 50, such as, use FET or GaN-HEMT etc.Semiconductor element 50 is such as normally-ON type.The grid of semiconductor element 50 is connected to the electronegative potential terminal 30d of rectification circuit 30.Thus, semiconductor element 50 is held in on-state.

The other end of inductor 43 is connected to lead-out terminal 7.The electronegative potential terminal 30d of rectification circuit 30 is connected to lead-out terminal 8.Output capacitor 48 is connected between lead-out terminal 7 and lead-out terminal 8.Lighting load 12 is and output capacitor 48 is connected in parallel between lead-out terminal 7 and lead-out terminal 8.

Control power supply portion 23 has rectifier cell 61 ~ rectifier cell 63, resistance 64, charge storage cell 65, capacitor 66, adjuster (regulator) 67, Zener diode (zener diode) 68 and semiconductor element 70.

Rectifier cell 61, rectifier cell 62 are such as diode.The anode (anode) of rectifier cell 61 is the high potential terminal 30c being connected to rectification circuit 30 via distribution 27a.The anode of rectifier cell 42 is the electronegative potential terminal 30d being connected to rectification circuit 30 via distribution 27b.

For semiconductor element 70, such as, use FET or GaN-HEMT etc.Next, semiconductor element 70 is set to FET to be described.In this embodiment, semiconductor element 70 is n passage (channel) FET strengthening (enhancement) type.Semiconductor element 70 has source electrode, drain electrode and grid.The current potential of drain electrode is set to the current potential higher than source electrode.Grid is used to switching first state and the second state, and described first state refers to that electric current flows through between source electrode and drain electrode, and described second state refers to that the electric current flow through between source electrode and drain electrode compared with the first state is little.In the second state, electric current does not flow through in fact between source electrode and drain electrode.Semiconductor element 70 both can be p channel-style, also can be vague and general (depression) type.Such as when making semiconductor element 70 for p channel-style, the current potential of source electrode is set to the current potential higher than drain electrode.

The drain electrode of semiconductor element 70 is connected to the negative electrode (cathode) of rectifier cell 61 and the negative electrode of rectifier cell 62.That is, the drain electrode of semiconductor element 70 is via rectifier cell 61, rectifier cell 62 and be connected to the first power supply feed path 21a.The source electrode of semiconductor element 70 is connected to the anode of rectifier cell 63.The grid of semiconductor element 70 is connected to the negative electrode of Zener diode 68.In addition, the grid of semiconductor element 70 is connected to the high potential terminal 30c of rectification circuit 30 via resistance 64.

The negative electrode of rectifier cell 63 is connected to one end of charge storage cell 65 and the input terminal of adjuster 67.The lead-out terminal of adjuster 67 is connected to one end of control part 22 and capacitor 66.

Electric current with each polarity of the applying of alternating voltage VCT is the drain electrode flowing through semiconductor element 70 via rectifier cell 61.Thus, the drain electrode of semiconductor element 70 is applied to pulsating voltage alternating voltage VCT full-wave rectification obtained.

For the negative electrode of Zener diode 68, apply pulsating voltage via resistance 64 and rectifier cell 61.Thus, the grid of semiconductor element 70 is applied to the voltage fixing in fact of the puncture voltage corresponding to Zener diode 68.Be accompanied by this, electric current fixing in fact flows through between the Drain-Source of semiconductor element 70.Semiconductor element 70 such as plays function as determining current element.The electric current of wiring part 27 is flow through in semiconductor element 70 adjustment.

Charge storage cell 65 is connected between the negative electrode of rectifier cell 63 and the electronegative potential terminal 30d of rectification circuit 30.In this embodiment, charge storage cell 65 is capacitor.Charge storage cell 65 makes the pulsating voltage smoothing supplied via rectifier cell 63 from the source electrode of semiconductor element 70, and pulsating voltage is converted to direct voltage.

Adjuster 67 is for comprising the what is called three terminal adjuster of input terminal, lead-out terminal and common terminal.The input terminal of adjuster 67 is connected to charge storage cell 65.Thus, charge storage cell 65 utilized to the input terminal input of adjuster 67 and carried out the direct voltage of smoothing.The lead-out terminal of adjuster 67 is connected to control part 22.The common terminal of adjuster 67 is connected to the electronegative potential terminal 30d of rectification circuit 30.Adjuster 67 produces the driving voltage VDD of direct current fixing in fact from inputted direct voltage, and exports control part 22 to.Thus, driving voltage VDD is supplied to control part 22, thus control part 22 action.

Capacitor 66 is connected to the lead-out terminal of adjuster 67.Capacitor 66 is such as used to the noise etc. removing driving voltage VDD.Thus, driving voltage VDD is supplied to control part 22.

Control power supply portion 23 also comprises resistance 71, resistance 72.One end of resistance 71 is connected to the negative electrode of rectifier cell 61, rectifier cell 62.The other end of resistance 71 is connected to one end of resistance 72.The other end of resistance 72 is connected to the electronegative potential terminal 30d of rectification circuit 30.The contact of resistance 71, resistance 72 is connected to control part 22.Thus, the voltage corresponding with the voltage ratio of resistance 71, resistance 72 is inputed to control part 22 by as detecting voltage, and described detection voltage is used to the absolute value detecting alternating voltage VCT.

Control part 22 such as detects the angle of flow of alternating voltage VCT based on detecting voltage.Control part 22 produces dim signal DMS based on this testing result, and this dim signal DMS is inputed to feedback circuit 25.The pwm signal corresponding with the detected angle of flow is such as inputed to feedback circuit 25 as dim signal DMS by control part 22.

Electric current adjustment part 24 has resistance 75, resistance 76 and switch element 78.For switch element 78, such as, use FET or GaN-HEMT etc.Next, switch element 78 is set to FET to be described.

One end of resistance 75 is connected to the source electrode of semiconductor element 70.The other end of resistance 75 is connected to the drain electrode of switch element 78.The grid of switch element 78 is connected to control part 22 via resistance 76.The gate input control signal CGS of control part 22 pairs of switch elements 78.For switch element 78, such as, normal off is used to open (normally off) type.Such as by the control signal CGS inputted from control part 22 is switched to Hi (height) from Lo (low), and switch element 78 is changed to on-state from off-state.

When making switch element 78 for on-state, the part flowing through the electric current of the first power supply feed path 21a such as flows through individual path 28 via rectifier cell 61, rectifier cell 62 and semiconductor element 70.That is, by making switch element 78 for on-state, electric current adjustment part 24 becomes conducting state, and by making switch element 78 be off state, electric current adjustment part 24 becomes nonconducting state.

Feedback circuit 25 has differential amplifier circuit 80 and semiconductor element 100.In this embodiment, semiconductor element 100 is npn transistor.Semiconductor element 100 is the element of normal off open form.Semiconductor element 100 also can be pnp transistor or FET etc.Semiconductor element 100 also can be normally-ON type.

Differential amplifier circuit 80 such as has operational amplifier (operational amplifier) 81, resistance 82 and capacitor 83.Resistance 82 is connected between the lead-out terminal of operational amplifier 81 and the reversed input terminal of operational amplifier 81.Capacitor 83 is connected in parallel in resistance 82.That is, differential amplifier circuit 80 has negative feedback.

The non-inverting input terminal of operational amplifier 81 is connected to one end of resistance 84.The other end of resistance 84 is connected to one end of one end of resistance 85, one end of resistance 86 and capacitor 87.The other end of capacitor 87 is connected to the electronegative potential terminal 30d of rectification circuit 30.The other end of resistance 85 is connected to lead-out terminal 7.The other end of resistance 86 is connected to one end of lead-out terminal 8 and resistance 88.The other end of resistance 88 is connected to the electronegative potential terminal 30d of rectification circuit 30.

Thus, for the non-inverting input terminal of operational amplifier 81, the direct voltage that input utilizes resistance 85, resistance 86 to be applied to the second direct voltage VDC2 dividing potential drop between lead-out terminal 7 and lead-out terminal 8 and obtains is as detecting voltage.That is, the non-inverting input terminal of operational amplifier 81 is connected to the end of the low potential side of lighting load 12.Thus, the electric current flowing through lighting source 16 can be detected.When the light-emitting components such as LED are used for lighting source 16, the voltage of lighting source 16 falls voltage corresponding to forward and is fix in fact.Therefore, when the light-emitting components such as LED are used for lighting source 16, by lighting source 16 being connected to the end of the low potential side of lighting load 12, and can suitably detect the electric current flowing through lighting source 16.

The reversed input terminal of operational amplifier 81 is connected to one end of resistance 90.The other end of resistance 90 is connected to one end of resistance 91 and one end of capacitor 92.The other end of capacitor 92 is connected to the electronegative potential terminal 30d of rectification circuit 30.The other end of resistance 91 is connected to control part 22.So, the reversed input terminal of operational amplifier 81 is connected to control part 22 via resistance 90,91.Thus, the dim signal DMS from control part 22 is inputted to the reversed input terminal of operational amplifier 81.

Capacitor 92 is such as utilized to make pwm signal smoothing and the direct voltage obtained is inputed to the reversed input terminal of operational amplifier 81 as dim signal DMS.For the reversed input terminal of operational amplifier 81, such as input corresponds to the direct voltage of the degree of dimming of dimmer 3 as dim signal DMS.The voltage level (level) of dim signal DMS sets corresponding to the voltage level of the detection voltage inputing to non-inverting input terminal.More specifically, the voltage level of dim signal DMS such as corresponding to required degree of dimming be set to when lighting source 16 identical in fact with the voltage level of detection voltage during Intensity LEDs corresponding to this degree of dimming.

So, for the non-inverting input terminal of operational amplifier 81, input the detection voltage corresponding with the electric current flowing through lighting source 16, for the reversed input terminal input dim signal DMS of operational amplifier 81.Thus, export from the lead-out terminal of operational amplifier 81 signal corresponding to the difference detecting voltage and dim signal DMS.Be greater than dim signal DMS along with detection voltage becomes, the output of operational amplifier 81 also becomes large.That is, when overcurrent flows through lighting source 16, the output of operational amplifier 81 becomes large.So, in this embodiment, dim signal DMS is used as fiducial value.In addition, when not carrying out light modulation, also the direct voltage fixing in fact becoming fiducial value can be inputed to the reversed input terminal of operational amplifier 81.

The collector electrode (collector) of semiconductor element 100 is connected to one end of divider resistance 47.The collector electrode of semiconductor element 100 is electrically connected at the grid of current controling element 41 via divider resistance 47.The emitter (emitter) of semiconductor element 100 is connected to one end of resistance 101.The other end of resistance 101 is connected to the electronegative potential terminal 30d of rectification circuit 30.Thus, the emitter of semiconductor element 100 is set to the current potential lower than the current potential of the source electrode of current controling element 41.The base stage (base) of semiconductor element 100 is connected to the lead-out terminal of operational amplifier 81.Thus, the electric current flowing through the emitter-inter-collector of semiconductor element 100 is controlled by the output from operational amplifier 81.

Semiconductor element 100 has the 3rd state and the 4th state, and described 3rd state refers to that electric current flows through between collector electrode and emitter, and described 4th state refers to that the electric current flow through between collector electrode and emitter compared with the 3rd state is little.3rd state is such as on-state, and the 4th state is such as off state.3rd state is not limited to on-state.4th state is not limited to off-state.3rd state can be the relatively large free position of the electric current of flowing compared with the 4th state.4th state can be the relatively little free position of the electric current of flowing compared with the 3rd state.

In this embodiment, semiconductor element 100 is normal off open form, and by making the current potential of current potential higher than emitter of base stage, and be the 3rd state from the 4th state variation.Such as by making the current potential of current potential higher than emitter of base stage, semiconductor element 100 is changed to on-state from off-state.

As mentioned above, when detecting voltage and being greater than dim signal DMS, the output of operational amplifier 81 becomes large.Therefore, semiconductor element 100 such as becomes on-state when detecting voltage and being greater than dim signal DMS, becomes off-state when detection voltage is below dim signal DMS.Such as be greater than dim signal DMS along with detection voltage becomes, the ER effect of the emitter-inter-collector of semiconductor element 100 is large.

In addition, semiconductor element 100 collector electrode so that be connected to one end of resistance 102 and one end of capacitor 103.The other end of resistance 102 is connected to the base stage of semiconductor element 100.The other end of capacitor 103 is connected to the electronegative potential terminal 30d of rectification circuit 30.The base stage of semiconductor element 100 and then be connected to one end of resistance 104.The other end of resistance 104 is connected to the electronegative potential terminal 30d of rectification circuit 30.So, the reference potential of feedback circuit 25 is set to the current potential of the electronegative potential terminal 30d of rectification circuit 30.That is, the reference potential of feedback circuit 25 and the reference potential of dc-dc 20b share.The reference potential of feedback circuit 25 is identical in fact with the reference potential of dc-dc 20b.

Fig. 3 (a) and Fig. 3 (b) is the curve chart of an example of the action of the control part schematically showing execution mode.

The transverse axis of Fig. 3 (a) and Fig. 3 (b) is time t.

The longitudinal axis of Fig. 3 (a) is for detecting voltage Vdet.

The longitudinal axis of Fig. 3 (b) is the magnitude of voltage of control signal CGS.

In this embodiment, alternating voltage VCT full-wave rectification is produced detection voltage Vdet.When not carrying out full-wave rectification, the longitudinal axis of Fig. 3 (a) is the absolute value detecting voltage Vdet.

As shown in Fig. 3 (a) and Fig. 3 (b), control part 22 such as sets these two threshold values of first threshold voltage Vth1 and Second Threshold voltage Vth2 to detection voltage Vdet.First threshold voltage Vth1 is such as set to the degree slightly larger than 0V.First threshold voltage Vth1 is such as being used for detecting the threshold value of zero crossing of voltage Vdet (alternating voltage VCT).

As shown in the signal S11 ~ S13 of Fig. 3 (a) and Fig. 3 (b), when detecting voltage Vdet and being less than first threshold voltage Vth1, control signal CGS is set as Hi by control part 22.That is, make switch element 78 for on-state, and make electric current adjustment part 24 for conducting state.

Second Threshold voltage Vth2 is the threshold value with deciding sequential electric current adjustment part 24 being switched to nonconducting state.Second Threshold voltage Vth2 is set to be higher than first threshold voltage Vth1.

As shown in signal S11, be changed in the scope of maximum in detection voltage Vdet (absolute value) from minimum value (such as 0V), when detecting voltage Vdet and becoming first threshold more than voltage Vth1 in the sequential being less than Second Threshold voltage Vth2, become the sequential of Second Threshold voltage Vth2 at detection voltage Vdet, control signal CGS is switched to Lo from Hi by control part 22.Switch element 78 is switched to off-state from on-state, makes electric current adjustment part 24 for nonconducting state.

On the other hand, as shown in signal S12, be changed in the scope of maximum at detection voltage Vdet from minimum value, when detecting voltage Vdet and becoming first threshold more than voltage Vth1 in the sequential becoming Second Threshold more than voltage Vth2, become the sequential of first threshold more than voltage Vth1 at detection voltage Vdet, control signal CGS is switched to Lo from Hi by control part 22.

In addition, as shown in signal S13, be changed in the scope of minimum value at detection voltage Vdet from maximum, when detecting voltage Vdet and becoming first threshold more than voltage Vth1, become the sequential of first threshold more than voltage Vth1 at detection voltage Vdet, control signal CGS is switched to Lo from Hi by control part 22.Such as be changed in the scope of minimum value at detection voltage Vdet from maximum, be less than the sequential of Second Threshold voltage Vth2 at detection voltage Vdet, control part 22 makes lighting load 12 extinguish.

So, control part 22 is when detecting voltage Vdet and being less than first threshold voltage Vth1, make electric current adjustment part 24 for conducting state, when detecting voltage Vdet and becoming first threshold more than voltage Vth1, make electric current adjustment part 24 for nonconducting state, and being changed in the scope of maximum at detection voltage Vdet from minimum value, is that the sequential time delay of nonconducting state is to detection voltage Vdet becomes Second Threshold more than voltage Vth2 by making electric current adjustment part 24.

In addition, so-called voltage Vdet is changed to maximum scope from minimum value is detected, in other words as the scope of the phase place detecting voltage Vdet (alternating voltage VCT) from 0 ° to 90 °.So-called detect voltage Vdet is changed to minimum value scope from maximum, in other words as the scope of the phase place detecting voltage Vdet from 90 ° to 180 °.

" detect the sequential that voltage Vdet is less than Second Threshold voltage Vth2 " and such as both can judge based on detection voltage Vdet, also can judge based on the time from control signal CGS being set as the sequential of Hi.That is, " sequential that voltage Vdet is less than Second Threshold voltage Vth2 is detected ", in other words as " when detection voltage Vdet is less than Second Threshold voltage Vth2 ".In addition, " detecting the sequential that voltage Vdet is less than Second Threshold voltage Vth2 ", in other words as " when the elapsed time from control signal CGS being set as the sequential of Hi is less than the stipulated time ".Also identical about " detecting the sequential that voltage Vdet becomes Second Threshold voltage Vth2 " and " detecting the sequential that voltage Vdet becomes Second Threshold more than voltage Vth2 " etc.

So, control part 22 makes switch element 78 for on-state when being less than first threshold voltage Vth1.Thus, such as make the maintenance electric current needed for triac contained in dimmer 3 connection flow through electric current adjustment part 24 (individual path 28).Thus, the having stable behavior of dimmer 3 can such as be made.

In addition, control part 22 according to carried out phase control alternating voltage VCT rising sequential and make timing variations electric current adjustment part 24 being set to nonconducting state.Thus, the action of dimmer 3 such as can be made more stable.

Second Threshold voltage Vth2 such as has the forward voltage of the lighting source 16 of light-emitting component (forward voltage) according to use and sets.Such as in the scaled value of alternating voltage VCT, Second Threshold voltage Vth2 is set to become more than the forward voltage of lighting source 16 and scope below the maximum of alternating voltage VCT.The scaled value of so-called alternating voltage VCT refers to and will correspond to the magnitude of voltage detecting voltage Vdet and be converted to the value of the magnitude of voltage corresponding to alternating voltage VCT according to the voltage ratio of resistance 71, resistance 72 etc.Such as when the effective value of supply voltage VIN is 100V (maximum is 141V), the forward voltage of lighting source 16 is such as about 60V.Second Threshold voltage Vth2 is such as set to the value of 60V dividing potential drop gained.

In addition, detection voltage Vdet is such as less than the interval Toff of blocking-up that the interval judgement of first threshold voltage Vth1 is the angle of flow control of dimmer 3 by control part 22.And, the interval Ton of conducting that the angle of flow that the interval judgement that detection voltage Vdet is first threshold more than voltage Vth1 is dimmer 3 by control part 22 controls.Interval judgement control signal CGS being set to Lo is the interval Ton of conducting of the angle of flow control of dimmer 3.And the interval judgement that control signal CGS is set to Hi by control part 22 is the interval Toff of blocking-up that the angle of flow of dimmer 3 controls.

Thus, control part 22 is the angles of flow detecting alternating voltage VCT according to the interval Ton of conducting and the ratio blocking interval Toff.Control part 22 such as produces and makes the interval Ton of detected conducting be Hi and make the interval Toff of blocking-up be that the pwm signal of Lo is as dim signal DMS.The test example of the angle of flow is as also carried out based on the threshold value different from first threshold voltage Vth1.

Next, the action of lamp circuit 14 is described.

First, to the degree of dimming of dimmer 3 being set as roughly 100% and the situation inputted supply voltage VIN roughly being kept originally state and transmit, namely the situation of the highest the first direct voltage VDC1 of dc-dc 20b input is described.

When supply voltage VIN is supplied to lamp circuit 14, because output element 40 and current controling element 41 are the element of normally-ON type, therefore output element 40 and current controling element 41 are all connected.And electric current flows in the path of output element 40, current controling element 41, inductor 43, output capacitor 48, and output capacitor 48 is charged.The voltage at the two ends of output capacitor 48, voltage namely between lead-out terminal 7 and lead-out terminal 8 are supplied to the lighting source 16 of lighting load 12 as the second direct voltage VDC2.In addition, because output element 40 and current controling element 41 are connected, therefore reverse voltage is applied with to rectifier cell 42.Electric current does not flow through rectifier cell 42.

When the second direct voltage VDC2 reaches assigned voltage, electric current flows through lighting source 16, and lighting source 16 is lighted.Now, electric current flows in the path of output element 40, current controling element 41, inductor 43, output capacitor 48 and lighting source 16.Such as when lighting source 16 is LED, this assigned voltage is that voltage falls in the forward of LED, and determines according to lighting source 16.In addition, when lighting source 16 extinguishes, not streaming current, therefore output capacitor 48 keeps the value of output voltage.

The the first direct voltage VDC1 inputing to dc-dc 20b is enough high compared with the second direct voltage VDC2.That is, the potential difference Δ V between input and output is enough large.Therefore, the electric current flowing through inductor 43 increases.Due to feedback winding 44 and inductor 43 magnetic couplings, therefore have in the induction of feedback winding 44 and make coupling capacitor 45 side be the electromotive force of the polarity of high potential.Therefore, for the grid of output element 40, via coupling capacitor 45, supply is positive current potential relative to source electrode, and output element 40 maintains the state connected.

When the electric current flowing through current controling element 41 exceedes higher limit, the voltage between the Drain-Source of current controling element 41 sharply rises.Therefore, the voltage between the gate-to-source of output element 40 is lower than threshold voltage, and output element 40 disconnects.Higher limit is the saturation current value of current controling element 41, is specified by the current potential of the grid inputing to current controling element 41.The grid potential of current controling element 41 sets according to the electric current being supplied to divider resistance 46, the direct voltage of divider resistance 47, the voltage of lighting source 16, divider resistance 46, the voltage ratio of divider resistance 47 and the emitter-inter-collector of semiconductor element 100 via bias resistance 49.In addition, as mentioned above, the grid potential of current controling element 41 is negative potential relative to source electrode, therefore saturation current value can be restricted to appropriate value.

Inductor 43 makes electric current continue flowing in the path of rectifier cell 42, output capacitor 48 and lighting load 12.Now, because inductor 43 releases energy (energy), therefore the electric current of inductor 43 reduces.Therefore, have in the induction of feedback winding 44 and make coupling capacitor 45 side be the electromotive force of the polarity of electronegative potential.For the grid of output element 40, via coupling capacitor 45, supply is negative current potential relative to source electrode, and output element 40 maintains the state disconnected.

When the energy being stored in inductor 43 becomes zero, the electric current flowing through inductor 43 becomes zero.In feedback winding 44, the direction of the electromotive force of induction is again anti-phase, and induction makes coupling capacitor 45 side be the electromotive force of high potential.Thus, supply the current potential higher than source electrode to the grid of output element 40, output element 40 is connected again.Thus, the state reaching described assigned voltage is reverted to.

Thereafter, described action is repeated.Thus, output element 40 repeats automatically to the switching of connecting and disconnect, and the second direct voltage VDC2 to lighting source 16 supply, supply voltage VIN being reduced and obtain.That is, in lamp circuit 14, the switching frequency of output element 40 sets according to divider resistance 46, divider resistance 47 and feedback circuit 25.In addition, the electric current being supplied to lighting source 16 becomes the electric current fixing in fact being limited higher limit by current controling element 41.Therefore, lighting source 16 can be made stably to light.

The differential amplifier circuit 80 of feedback circuit 25 is according to corresponding to the detection voltage of electric current and the difference of dim signal DMS that flow through lighting source 16, and the base potential of semiconductor element 100 is changed.Such as when overcurrent flows through lighting source 16, detect voltage voltage level relative to dim signal DMS voltage level and more than high setting time, the base stage setting high potential of differential amplifier circuit 80 pairs of semiconductor elements 100, makes semiconductor element 100 be essentially on-state.

When semiconductor element 100 becomes on-state, the grid potential of current controling element 41 is such as set at the electronegative potential terminal 30d of rectification circuit 30.That is, to the grid potential setting negative potential of current controling element 41, current controling element 41 becomes off-state.Thus, the electric current flowing through lighting source 16 diminishes, and overcurrent can be suppressed to flow through lighting source 16.So, in this embodiment, feedback circuit 25 is based on detection voltage and dim signal DMS and FEEDBACK CONTROL dc-dc 20b.

When the sustainable vibration of output element 40, even if also identical with described in the case where there, described situation refers to that the degree of dimming of dimmer 3 is set to be less than the value of 100%, and the situation that the alternating voltage VCT inputted is transmitted by carrying out the angle of flow to control, namely dc-dc 20b is inputted to the situation of the first high direct voltage VDC1.The value of the first direct voltage VDC1 inputing to dc-dc 20b can be changed according to the degree of dimming of dimmer 3, thus control the mean value of output current.Therefore, light modulation can be carried out according to degree of dimming to the lighting source 16 of lighting load 12.

In addition, when the degree of dimming of dimmer 3 being set as less value, input to the first direct voltage VDC1 of dc-dc 20b lower time, even if output element 40 is connected, because the potential difference at the two ends of inductor 43 is little, the electric current therefore flowing through inductor 43 also cannot increase.Therefore, output element 40 does not become off-state and exports fixing direct current.That is, when the degree of dimming of dimmer 3 is little, the potential difference Δ V namely when between input and output is little, lamp circuit 14 carries out the action as series controller (series regulator).

So, lamp circuit 14 carries out switch motion when potential difference Δ V is greater than setting, carries out the action as series controller when potential difference Δ V is less than setting.When potential difference Δ V is large, potential difference Δ V and electric current long-pending large, when carrying out the action of series controller, loss becomes large.Therefore, when potential difference Δ V is large, carries out switch motion and be applicable to power reducing.In addition, when potential difference Δ V is little, because loss is little, therefore without the problem of carrying out action as series controller.

In addition, in lamp circuit 14, when potential difference Δ V is less than setting, output element 40 does not become off-state and make current oscillations under the lasting state maintaining connection, thus with the mean value of electric current, the lighting source 16 of lighting load 12 is lighted.In addition, when potential difference Δ V is less, direct current, under the lasting state maintaining connection, is exported to lighting load 12 and lighting source 16 is lighted by output element 40.Its result, in lamp circuit 14, can make output current be changed to continuously till zero.Such as in lighting device 10, the lighting source 16 of lighting load 12 can be made to extinguish reposefully.

In lamp circuit 14, till maximum when output current can be made to carry out switch motion from output element 40 according to potential difference Δ V is changed to minimum value when to export direct current under the on-state of lasting maintenance output element 40 continuously.Such as in lighting device 10, lighting source 16 can be made in the scope of 0 ~ 100% to carry out light modulation continuously.

In lamp circuit 14, feedback circuit 25 is connected to the end of the low potential side of lighting load 12, detects the electric current flowing through lighting source 16, and the action of FEEDBACK CONTROL dc-dc 20b according to its testing result.Even if input voltage distortion such as supply voltage VIN or alternating voltage VCT, the voltage of lighting source 16 is also still stable to a certain extent.Therefore, as mentioned above, detect by feedback circuit 25 being connected to the end of the low potential side of lighting load 12 electric current flowing through lighting source 16, such as, can improve the accuracy of detection of electric current.Such as when producing overcurrent, the electric current flowing through lighting source 16 can be made to stop immediately.And then, also can easily to the gate set negative potential of the current controling element 41 of normally-ON type.Thus, in lamp circuit 14, more practical Current Control and overcurrent protection can be carried out.

In addition, in lamp circuit 14, the reference potential of feedback circuit 25 and the reference potential of dc-dc 20b share.Thus, the variation of the second direct voltage VDC2 as output voltage can such as be suppressed.

Fig. 4 (a) and Fig. 4 (b) is the curve chart of the example schematically showing alternating voltage and control signal.

Fig. 4 (a) is the example schematically showing alternating voltage VCT in the lamp circuit of reference example and control signal CGS.

Fig. 4 (b) is the example schematically showing alternating voltage VCT in the lamp circuit 14 of present embodiment and control signal CGS.

As shown in Fig. 4 (a), in the lamp circuit of reference example, be changed in the scope of maximum at detection voltage Vdet from minimum value, when detecting voltage Vdet and becoming first threshold more than voltage Vth1 in the sequential being less than Second Threshold voltage Vth2, become the sequential of first threshold more than voltage Vth1 at detection voltage Vdet, control signal CGS is switched to Lo from Hi.

Such as when the rising sequential of alternating voltage VCT is below the forward voltage as the lighting source 16 of light-emitting component, if make electric current adjustment part 24 for nonconducting state, enough electric currents (maintenance electric current) then cannot be made to flow to lighting load 12 side from dimmer 3, and have the switch element 3s (such as triac) of dimmer 3 to repeat the situation of on-off.The misoperation of this dimmer 3 such as becomes flicker (flicker) (the successional change of brightness) and shows in lighting load 12.

For described situation, in the lamp circuit 14 of present embodiment, be changed in the scope of maximum at detection voltage Vdet from minimum value, when detecting voltage Vdet and becoming first threshold more than voltage Vth1 in the sequential being less than Second Threshold voltage Vth2, become the sequential of Second Threshold voltage Vth2 at detection voltage Vdet, control signal CGS is switched to Lo from Hi.

That is, in lamp circuit 14, before the rising sequential of alternating voltage VCT becomes the sequential of more than the forward voltage of lighting source 16, make electric current adjustment part 24 for conducting state.Thus, in the scope below forward voltage, electric current also can be made suitably to flow through the switch element 3s of dimmer 3, thus the misoperation of dimmer 3 can be suppressed.Such as can suppress the flicker of lighting load 12.Therefore, in the lamp circuit 14 of present embodiment, stable action can be obtained.

Fig. 5 (a) and Fig. 5 (b) is the curve chart of another example schematically showing alternating voltage and control signal.

Fig. 5 (a) and Fig. 5 (b) is an example of action when schematically showing to be connected to by lamp circuit corresponding to light-emitting components such as LED dimmer 3.Fig. 5 (a) is alternating voltage VCT when schematically showing to be connected to by the lamp circuit of described reference example corresponding to light-emitting component dimmer 3, the example detecting voltage Vdet, control signal CGS.Fig. 5 (b) schematically shows the alternating voltage VCT lamp circuit 14 of execution mode being connected to the situation of the dimmer 3 corresponding to light-emitting component, the example detecting voltage Vdet, control signal CGS.

In the dimmer 3 corresponding to light-emitting component, for switch element 3s, such as use triac (triac) or power (power) mos field effect transistor (Metal-Oxide-Semiconductor Field Effect Transistor, MOSFET) etc.In addition, the dimmer 3 corresponding to light-emitting component such as also comprises zero cross detection portion, degree of dimming configuration part and dimming control part.

The zero crossing of supply voltage VIN is detected in zero cross detection portion.Zero cross detection portion is connected to dimming control part, and the testing result of zero crossing is inputed to dimming control part.Degree of dimming configuration part is such as slide switch or dial switch etc.Degree of dimming configuration part is connected to dimming control part.The setting of the degree of dimming corresponding with the operation of user etc. is inputed to dimming control part.

Dimming control part is such as from detecting zero crossing after the stipulated time, makes switch element 3s be on-state.And dimming control part is the timing variations making switch element 3s switch to according to set degree of dimming connection.About dimming control part, such as degree of dimming lower (more close to 0%), more makes sequential time delay switch element 3s being switched to connection.Dimming control part is when again detecting zero crossing, makes switch element 3s be off state.Thus, supply voltage VIN is converted to the alternating voltage VCT having carried out phase control by dimmer 3.

In addition, dimming control part makes switch element 3s be that the conducting of on-state is interval, continues to input to make switch element 3s be the control signal of on-state to the control terminal of switch element 3s.Thus, the situation the voltage of load-side is high such as can be suppressed inferior, and switch element 3s repeats on-off.

As shown in Fig. 5 (a), when the dimmer 3 of the phase control mode corresponding to light-emitting component is connected to the lamp circuit of reference example, when cannot detect the zero crossing of supply voltage VIN exactly when cataclysm because of supply voltage VIN etc., have dimming control part misoperation, the angle of flow maintains the situation of unsure state.Such as there is following situation: in blocking-up interval, the absolute value of alternating voltage VCT maintains the state uprised.

As mentioned above, when the absolute value blocking interval alternating voltage VCT uprises, such as, suitably the angle of flow cannot be detected in lamp circuit 14.Carry out in the lamp circuit 14 of light modulation at the detection angle of flow, make corresponding to the variation of the angle of flow output change.Therefore, the main cause producing flicker is such as become.Such as suitably cannot carry out light modulation.

In addition, the dimmer 3 of the phase control mode of TW two wire is blocking the electric power guaranteeing dimmer 3 self in interval.Therefore, if the absolute value blocking interval alternating voltage VCT maintains the state uprised, then dimmer 3 cannot guarantee electric power.Therefore, when dimmer 3 is absorbed in abnormality as above, about output defect cycle half period to one that dimmer 3 can make alternating voltage VCT, guarantee the electric power of self.

Therefore, when lamp circuit 14 being connected to corresponding to light-emitting component dimmer 3, in the scaled value of alternating voltage VCT, Second Threshold voltage Vth2 is set as more than the voltage needed for action of dimmer 3 and scope below the maximum of alternating voltage VCT.Thus, such as the voltage blocking the part that interval absolute value uprises can be drawn to electric current adjustment part 24.Such as shown in Fig. 5 (b), after dimmer 3 produces misoperation, can automatically return to normal state.

Such as when described reference example, when corresponding to the dimmer 3 of light-emitting component and producing misoperation, must operate wall switch etc. the power supply of dimmer 3 and lighting device 10 temporarily be disconnected.In contrast, in lamp circuit 14, can automatically return to normal state.Thus, in lamp circuit 14, such as, can omit and allow user wait the man-hour of power supply on-off.In addition, dimmer 3 such as can be suppressed to be used for a long time under the state producing misoperation.

So, Second Threshold voltage Vth2 also can voltage needed for the action of dimmer 3 and setting.In this case, also stable action can be obtained in lamp circuit 14.In addition, in most cases, the voltage needed for action of dimmer 3 is lower than the forward voltage of lighting source 16.Therefore, when being set as more than the forward voltage of lighting source 16 by Second Threshold voltage Vth2, the misoperation of the dimmer 3 corresponding to light-emitting component also suitably can be suppressed.

Fig. 6 is the circuit diagram of another lamp circuit schematically showing execution mode.

As shown in Figure 6, in lamp circuit 114, control part 22 detects the voltage of smmothing capacitor 32.And in lamp circuit 114, in the scaled value of alternating voltage VCT, Second Threshold voltage Vth2 is set as more than the voltage of smmothing capacitor 32 and scope below the maximum of alternating voltage VCT by control part 22.Control part 22 such as according to the detected value of the voltage of smmothing capacitor 32, the value of Second Threshold voltage Vth2 is changed.

Fig. 7 (a) and Fig. 7 (b) is the curve chart of another example schematically showing alternating voltage and control signal.

Fig. 7 (a) and Fig. 7 (b) is an example of another action when schematically showing to be connected to by lamp circuit corresponding to incandescent lamp bulb etc. dimmer 3.Fig. 7 (a) be alternating voltage VCT, the control signal CGS schematically shown in the lamp circuit of reference example, smmothing capacitor 32 voltage VC one example.Fig. 7 (b) be alternating voltage VCT, the control signal CGS schematically shown in the lamp circuit 114 of execution mode, smmothing capacitor 32 voltage VC one example.

As shown in Fig. 7 (a), in the lamp circuit of reference example, during voltage VC lower than smmothing capacitor 32 of the voltage of alternating voltage VCT when raised, there is following situation, namely not flow enough electric currents at the switch element 3s of dimmer 3, switch element 3s becomes off-state.In this case, the charging of smmothing capacitor 32 cannot normally be carried out, such as, in lighting load 12, become flicker and show.

In contrast, in the lamp circuit 114 of execution mode, set Second Threshold voltage Vth2 according to the voltage VC of smmothing capacitor 32.Thus, as shown in Fig. 7 (b), switch element 3s in conducting interval can be suppressed to become off-state.Therefore, carry out the charging to smmothing capacitor 32 Absorbable organic halogens.The flicker of lighting load 12 can be suppressed.In addition, such as, can the forward voltage of the lighting sources such as LED 16 be set high, and high efficiency high pressure copped wave (chopper) circuit can be formed in power conversion unit 20.

So, Second Threshold voltage Vth2 also can set according to the voltage of smmothing capacitor 32.In this case, also stable action can be obtained in lamp circuit 114.In addition, under the state making lighting load 12 light, the voltage of the smmothing capacitor 32 when charging failed is identical in fact with the forward voltage of lighting source 16.Therefore, when Second Threshold voltage Vth2 is set as more than the forward voltage of lighting source 16, smmothing capacitor 32 can be charged.

Second Threshold voltage Vth2 such as also can set according to the maximum of alternating voltage VCT.In other words, electric current adjustment part 24 also can be made in the scope of 90 of alternating voltage VCT ° phase place for conducting state.But, as mentioned above, the voltage needed for the action of the forward voltage of lighting source 16, dimmer 3 or the voltage of smmothing capacitor 32 and set Second Threshold voltage Vth2.Thus, such as can make lamp circuit stably action, and the power consumption of electric current adjustment part 24 can be suppressed.Such as can make lamp circuit stably action, and the heating in electric current adjustment part 24 can be suppressed.

Above, faced by one side reference concrete example one, execution mode is illustrated, but is not limited to described content, also can carry out various distortion.

Such as output element 40 and current controling element 41 are not limited to GaN HEMT.Such as also can be semiconductor substrate use have as carborundum (Sic), gallium nitride (Gallium Nitride) (GaN) or diamond (diamond) as broad-band gap (wide bandgap) semiconductor (wide band gap semiconducter) and formation semiconductor element.Herein, so-called wide band gap semiconducter refers to that band gap is about the wide semiconductor of the GaAs (gallium arsenide) (GaAs) of 1.4eV than band gap.Such as comprise semiconductor, gallium phosphide (gallium phosphide) (GaP that band gap is more than 1.5eV, band gap is about 2.3eV), gallium nitride (GaN, band gap is about 3.4eV), diamond (C, band gap is about 5.27eV), aluminium nitride (aluminum nitride) (AlN, band gap is about 5.9eV) and carborundum (Sic) etc.This wide band gap semiconducter element is when making withstand voltage equal, comparable silicon (silicon) semiconductor element is little, therefore parasitic capacitance is little and can carry out high speed motion, therefore can shorten switch periods, and can realize the miniaturization of winding part or capacitor etc.

In said embodiment, output element 40 is connected with current controling element 41 cascade (cascode), utilizes output element 40 to carry out switch, and utilize current controling element 41 to carry out the control of electric current.Be not limited thereto, such as, also can only utilize current controling element 41 to carry out the control of switch and electric current.

The formation of power conversion unit 20 is not limited to formation mentioned above, can be any formation that the alternating electromotive force carrying out phase control can be changed to direct current power.In said embodiment, control part 22 controls to utilize the electric power of power conversion unit 20 to change by dim signal DMS being inputed to feedback circuit 25.The method utilizing control part 22 to control power conversion unit 20 is not limited to method mentioned above, can be any means of the formation corresponding to power conversion unit 20.Such as when power conversion unit 20 is for comprising copped wave (chopper) circuit of switch element, as long as control to utilize the electric power of power conversion unit 20 to change by the switch of control switch element.

In addition, lighting source 16 is not limited to LED, such as, can be organic electroluminescent (Electro-Luminescence, EL) or Organic Light Emitting Diode (Organic light-emitting diode, OLED) etc.In lighting load 12, also multiple lighting source 16 can be connected in series or in parallel.

Some execution modes of the present invention and embodiment are illustrated, but these execution modes or embodiment exemplarily propose, be not intended to limit scope of invention.The execution mode of these novelties or embodiment can be implemented with other various execution modes, and can carry out various omission, displacement, change in the scope of purport not departing from invention.These execution modes, embodiment or its distortion are contained in scope of invention or purport, and are contained in the scope with its equalization.

Claims (6)

1. a lamp circuit, is characterized in that, comprising:

Power conversion unit, is connected to dimmer via power supply feed path, and is connected to lighting load, and by the carrying out supplied from described dimmer, the alternating voltage of phase control is converted to direct voltage and is supplied to described lighting load;

Electric current adjustment part, there is the individual path being connected to described power supply feed path, and switched conductive state and nonconducting state, thus the electric current of described power supply feed path is flow through in adjustment, described conducting state instigates a part for the electric current flowing through described power supply feed path to flow through described individual path, and described nonconducting state refers to and do not make electric current flow through described individual path; And

Control part, when the detection voltage of described alternating voltage is less than first threshold voltage, described electric current adjustment part is made to be described conducting state, when described detection voltage becomes more than described first threshold voltage, described electric current adjustment part is made to be described nonconducting state, and be changed in the scope of maximum at described detection voltage from minimum value, by make described electric current adjustment part be sequential time delay to the described detection voltage of described nonconducting state become higher than described first threshold voltage Second Threshold voltage more than.

2. lamp circuit according to claim 1, is characterized in that:

Described lighting load comprise there is forward voltage light-emitting component as lighting source,

In the scaled value of described alternating voltage, described Second Threshold voltage is more than the described forward voltage of described lighting source and below the maximum of described alternating voltage.

3. lamp circuit according to claim 1, is characterized in that:

Described dimmer comprises the interval switch element with blocking interval of the conducting switching described alternating voltage, be in the described conducting interval of on-state making described switch element, be that the control signal of on-state continues to input to described switch element by making described switch element

In the scaled value of described alternating voltage, more than the voltage of described Second Threshold voltage needed for the action of described dimmer and below the maximum of described alternating voltage.

4. lamp circuit according to claim 1, is characterized in that,

Described power conversion unit comprises: rectification circuit, and described ac voltage rectifier is converted to commutating voltage; And smmothing capacitor, make described commutating voltage smoothing;

In the scaled value of described alternating voltage, described Second Threshold voltage becomes more than the voltage of described smmothing capacitor and below the maximum of described alternating voltage.

5. a lighting device, is characterized in that, comprising:

Lighting load; And

Lamp circuit according to any one of claim 1 to 4, to described lighting load supply electric power.

6. an illuminator, is characterized in that, comprising:

Lighting device according to claim 5; And

Dimmer, is supplied to described lighting device by the alternating voltage carrying out phase control.