U.S. patent application number 15/373942 was filed with the patent office on 2018-03-01 for ripple removing circuit and led control circuit applying the same.
This patent application is currently assigned to JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD.. The applicant listed for this patent is JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD.. Invention is credited to Lang BAI, Biliang HUANG, Yuancheng REN, Xunwei ZHOU.
Application Number | 20180063911 15/373942 |
Document ID | / |
Family ID | 58085637 |
Filed Date | 2018-03-01 |
United States Patent
Application |
20180063911 |
Kind Code |
A1 |
BAI; Lang ; et al. |
March 1, 2018 |
RIPPLE REMOVING CIRCUIT AND LED CONTROL CIRCUIT APPLYING THE
SAME
Abstract
A ripple removing circuit and an LED control circuit applying
the same are described herein. The LED control circuit receives
alternating current input, converts the input into direct current
with ripples and supplies power for an LED load. The direct current
with ripples is connected to a positive end of the LED load, a
negative end of the load is connected to a first end of a
regulation tube, and a second end of the regulation tube is
grounded. A first capacitor is connected between a control end of
the regulation tube and the ground, and the time constant of the
filter circuit formed by the first capacitor, a current generating
circuit and a current source is far greater than a power frequency
period. The current flowing across the regulation tube is
approximately a direct current free of ripples, thereby decreasing
the current ripples going across the LED load.
Inventors: |
BAI; Lang; (Hangzhou,
CN) ; HUANG; Biliang; (Hangzhou, CN) ; REN;
Yuancheng; (Hangzhou, CN) ; ZHOU; Xunwei;
(Hangzhou, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD. |
Hangzhou |
|
CN |
|
|
Assignee: |
JOULWATT TECHNOLOGY (HANGZHOU) CO.,
LTD.
Hangzhou
CN
|
Family ID: |
58085637 |
Appl. No.: |
15/373942 |
Filed: |
December 9, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B 45/00 20200101;
Y02B 20/345 20130101; H05B 45/395 20200101; Y02B 20/30
20130101 |
International
Class: |
H05B 33/08 20060101
H05B033/08 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2016 |
CN |
201610795710.7 |
Claims
1. A ripple removing circuit, comprising: a regulation tube in
serial connection with a load, a first end of the regulation tube
being connected with the load, and a second end of the regulation
tube being connected with a low potential end of an input voltage;
a first capacitor, both ends of the first capacitor being connected
with a control end and the second end of the regulation tube,
respectively; a current source in parallel connection with the
first capacitor; and a current generating circuit, wherein input
ends of the current generating circuit are connected with a high
potential end and a low potential end, respectively, the first end
of the regulation tube serves as the high potential end of the
current generating circuit, and a common end of the first capacitor
and the current source or a ground potential end serves as the low
potential end of the current generating circuit; a current
generated by the current generating circuit is regulated according
to voltages at the high potential end and the low potential end;
and an output end of the current generating circuit is connected
with the common end of the first capacitor and the current
source.
2. The ripple removing circuit according to claim 1, wherein the
second end of the regulation tube is connected to the low potential
end of the input voltage through a first resistor, and one end of
the first capacitor is connected with the second end of the
regulation tube through the first resistor.
3. The ripple removing circuit according to claim 1, wherein one
end of the first capacitor is connected with the control end of the
regulation tube through a first operational amplifier, a first
input end of the first operational amplifier is connected with the
first capacitor, a second input end of the first operational
amplifier receives a current sampling signal representing
instantaneous current flowing across the regulation tube, and an
output end of the first operational amplifier is connected with the
control end of the regulation tube.
4. The ripple removing circuit according to claim 1, further
comprising a nonlinear regulation circuit, wherein the nonlinear
regulation circuit charges or discharges the first capacitor
according to a comparison difference between the current generated
by the current generating circuit and a current of the current
source.
5. The ripple removing circuit according to claim 2, further
comprising a nonlinear regulation circuit, wherein the nonlinear
regulation circuit charges or discharges the first capacitor
according to a comparison difference between the current generated
by the current generating circuit and a current of the current
source.
6. The ripple removing circuit according to claim 3, further
comprising a nonlinear regulation circuit, wherein the nonlinear
regulation circuit charges or discharges the first capacitor
according to a comparison difference between the current generated
by the current generating circuit and a current of the current
source.
7. The ripple removing circuit according to claim 4, wherein a
charging or discharging current is in proportional relation with
the difference between the currents generated by the current
generating circuit and the current source.
8. The ripple removing circuit according to claim 4, wherein an
input end of the nonlinear regulation circuit is connected with the
current generating circuit and the common end of the current
source, and an output end of the nonlinear regulation circuit is
connected with the first capacitor.
9. The ripple removing circuit according to claim 4, wherein when
the current i02 generated by the current generating circuit is
greater than the current i01 of the current source, a charging
current for the first capacitor of the nonlinear regulation circuit
is M*(i02-i01); and when the current i02 generated by the current
generating circuit is smaller than the current of the current
source i01, a discharging current for the first capacitor of the
nonlinear regulation circuit is N*(i01-i02).
10. The ripple removing circuit according to claim 7, wherein N/M
is greater than or equal to 1.
11. The ripple removing circuit according to claim 1, wherein the
current generating circuit is a second resistor, and two ends of
the second resistor are connected with the first end of the
regulation tube and the common end of the current source and the
first capacitor, respectively.
12. The ripple removing circuit according to claim 2, wherein the
current generating circuit is a second resistor, and two ends of
the second resistor are connected with the first end of the
regulation tube and the common end of the current source and the
first capacitor, respectively.
13. The ripple removing circuit according to claim 3, wherein the
current generating circuit is a second resistor, and two ends of
the second resistor are connected with the first end of the
regulation tube and the common end of the current source and the
first capacitor, respectively.
14. The ripple removing circuit according to claim 1, wherein the
current generating circuit comprises a voltage-to-current
conversion circuit and a current mirror module, an input end of the
voltage-to-current conversion circuit is connected with the first
end of the regulation tube, the other end of the voltage-to-current
conversion circuit is connected with the current mirror module, and
an output end of the current mirror module is connected with the
common end of the current source and the first capacitor.
15. An LED control circuit, comprising an LED driving circuit and
the ripple removing circuit as claimed in claim 1, the LED driving
circuit receiving alternating current input and then supplying
power for an LED load, and the ripple removing circuit being
coupled to the LED driving circuit.
16. An LED control circuit, comprising an LED driving circuit and
the ripple removing circuit as claimed in claim 2, the LED driving
circuit receiving alternating current input and then supplying
power for an LED load, and the ripple removing circuit being
coupled to the LED driving circuit.
17. An LED control circuit, comprising an LED driving circuit and
the ripple removing circuit as claimed in claim 3, the LED driving
circuit receiving alternating current input and then supplying
power for an LED load, and the ripple removing circuit being
coupled to the LED driving circuit.
18. An LED control circuit, comprising an LED driving circuit and
the ripple removing circuit as claimed in claim 4, the LED driving
circuit receiving alternating current input and then supplying
power for an LED load, and the ripple removing circuit being
coupled to the LED driving circuit.
19. An LED control circuit, comprising an LED driving circuit and
the ripple removing circuit as claimed in claim 5, the LED driving
circuit receiving alternating current input and then supplying
power for an LED load, and the ripple removing circuit being
coupled to the LED driving circuit.
20. An LED control circuit, comprising an LED driving circuit and
the ripple removing circuit as claimed in claim 5, the LED driving
circuit receiving alternating current input and then supplying
power for an LED load, and the ripple removing circuit being
coupled to the LED driving circuit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35
U.S.C. .sctn.119(a) on Patent Application No(s). 201610795710.7
filed in People's Republic of China on Aug. 31 2016, the entire
contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This invention relates to the technical field of power
electronics and, more particular, to a ripple removing circuit and
a light emitting diode (LED) control circuit applying the same.
Description of the Related Art
[0003] In the prior art, the mode where a light emitting diode
(LED) driving circuit receives alternating current input and
converts the input into direct current power output with sine
ripples is mostly adopted for LED driving. As shown in FIG. 1, when
the LED driving circuit has a power factor correction function,
ripples at the output end are larger. Therefore, direct voltage and
direct current with secondary power frequency ripples exist on an
LED load. The ripples on the LED hurt human eyes, and thus the LED
load is often required to filter out the sine ripples carried by
the current in actual application.
[0004] Large electrolytic capacitors are mainly adopted to serve as
C01 in the prior art, are high in cost and do not facilitate
circuit integration. Meanwhile, since the output power of the LED
driving circuit contains sine ripples, in order to filter out the
sine ripples of the current, output voltage is required to be
controlled to include voltage waveforms containing sine ripples so
as to ensure that the product of the LED current and the output
voltage is equal to the output power of the LED driving circuit. In
the prior art, the current of the LED load is mainly controlled to
be a direct current approximately containing no ripples through a
constant current control circuit with a filter capacitor, and
meanwhile the sine ripples in the output voltage are exerted to
both ends of the constant current control circuit so as to ensure
that the voltages at both ends of the LED load remain approximately
unchanged. In the prior art, the shortcoming of filter capacitor
control or adoption of a fixed current charge-discharge mode is low
in response speed, the direct current of the LED load carries
triangular ripples, ripple amplitude is fixed, and the ripple
proportion is very large when the average current is small.
BRIEF SUMMARY OF THE INVENTION
[0005] In view of this, the present invention aims at providing a
ripple removing circuit for removing load voltage and current
ripples and an LED control circuit applying the same, solving the
technical problem of current ripple elimination which cannot be
solved in the prior art.
[0006] The technical scheme of the present invention is to provide
a ripple removing circuit with the following circuit structure,
comprising:
a regulation tube in serial connection with a load, a first end of
the regulation tube being connected with the load, and a second end
of the regulation tube being connected with a low potential end of
an input voltage; a first capacitor, both ends of the first
capacitor being connected with a control end and the second end of
the regulation tube, respectively; a current source in parallel
connection with the first capacitor; and a current generating
circuit, wherein input ends of the current generating circuit are
connected with a high potential end and a low potential end,
respectively, the first end of the regulation tube serves as the
high potential end of the current generating circuit, and a common
end of the first capacitor and the current source or a ground
potential end serves as the low potential end of the current
generating circuit; a current generated by the current generating
circuit is regulated according to voltages at the high potential
end and the low potential end; and an output end of the current
generating circuit is connected with the common end of the first
capacitor and the current source.
[0007] Preferably, the second end of the regulation tube may be
connected to the low potential end of the input voltage through a
first resistor, and one end of the first capacitor may be connected
with the second end of the regulation tube through the first
resistor.
[0008] Preferably, one end of the first capacitor may be connected
with the control end of the regulation tube through a first
operational amplifier, a first input end of the first operational
amplifier may be connected with the first capacitor, the second
input end of the first operational amplifier may receive a current
sampling signal representing instantaneous current flowing across
the regulation tube, and the output end of the first operational
amplifier may be connected with the control end of the regulation
tube.
[0009] Preferably, the ripple removing circuit may further comprise
a nonlinear regulation circuit, the nonlinear regulation circuit
may charge or discharge the first capacitor according to the
comparison difference of the current generated by the current
generating circuit and the current source.
[0010] Preferably, the charging or discharging current may be in a
proportional relation with the difference of the current generated
by the current generating circuit and the current source.
[0011] Preferably, the input end of the nonlinear regulation
circuit may be connected with the common end of the current
generating circuit and the current source, and the output end of
the nonlinear regulation circuit may be connected with the first
capacitor.
[0012] Preferably, when the current i02 generated by the current
generating circuit may be greater than the current i01 of the
current source, a charging current for the first capacitor of the
nonlinear regulation circuit may be M*(i02-i01); when the current
i02 generated by the current generating circuit may be smaller than
the current i01 of the current source I01, the discharging current
for the first capacitor of the nonlinear regulation circuit may be
N*(i01-i02).
[0013] Preferably, N/M may be greater than or equal to 1.
[0014] Preferably, the current generating circuit may be a second
resistor, and both ends of the second resistor may be respectively
connected with the first end of the regulation tube and the common
end of the current source and the first capacitor.
[0015] Preferably, the current generating circuit may comprise a
voltage-to-current conversion circuit and a current mirror module,
the input end of the voltage-to-current conversion circuit may be
connected with the first end of the regulation tube, the other end
of the voltage-to-current conversion circuit may be connected with
the current mirror module, and the output end of the current mirror
module may be connected with the common end of the current source
and the first capacitor.
[0016] According to another solution scheme of the present
invention, an LED control circuit with the following structure is
provided. The LED control circuit comprises an LED driving circuit
and any one ripple removing circuit mentioned above, the LED
driving circuit receives alternating current input and then
supplies power for an LED load, and the ripple removing circuit is
coupled to the LED driving circuit.
[0017] Compared with the prior art, by the adoption of the circuit
structure of the present invention, the present invention has the
following advantages that the LED control circuit receives
alternating current input, converts the input into direct current
with ripples and supplies power for the LED load. The direct
current with ripples is connected to the positive end of the LED
load, the negative end of the LED load is connected to the first
end of the regulation tube, and the second end of the regulation
tube is grounded; a first capacitor is connected between the
control end of the regulation tube and the ground, and the time
constant of a filter circuit formed by the first capacitor, the
current generating circuit and the current source is far greater
than a power frequency period. Therefore, the voltage on the first
capacitor is approximately a DC voltage free of ripples, so that
the current flowing across the regulation tube is approximately a
direct current free of ripples, thereby decreasing the current
ripples going across the LED load, and input current ripples are
converted into voltage ripples at the drain-source end of the
regulation tube by the input capacitor. A DC component of the
voltage ripples at the drain-source end of the regulation tube can
be controlled by setting the value of the current of the current
source. The ripple removing effect is remarkable, and the
implementation costs are low. Due to the fact that the input of the
current generating circuit is connected to the first end of the
regulation tube and the output of the current generating circuit is
connected to the first capacitor, when the load changes, the
voltage at the first end of the regulation tube changes, the
voltage on the first capacitor can rapidly reflect the load change,
and the system responds rapidly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a circuit structure diagram of an LED control
circuit in the prior art;
[0019] FIG. 2 is a circuit structure diagram of the first
embodiment of a ripple removing circuit of the present
invention;
[0020] FIG. 3 is a circuit structure diagram of the second
embodiment of the ripple removing circuit of the present
invention;
[0021] FIG. 4 is a circuit structure diagram of the third
embodiment of the ripple removing circuit of the present
invention;
[0022] FIG. 5 is a circuit structure diagram of the fourth
embodiment of the ripple removing circuit of the present
invention;
[0023] FIG. 6 is a circuit structure diagram of a current
generating circuit of the present invention;
[0024] FIG. 7 is a circuit structure diagram of the fifth
embodiment of the ripple removing circuit of the present
invention;
[0025] FIG. 8 is a circuit structure diagram of the sixth
embodiment of the ripple removing circuit of the present invention;
and
[0026] FIG. 9 is a circuit structure diagram of a nonlinear
regulation circuit.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The preferred embodiments of the present invention are
described in detail below in combination with accompanied drawings,
but the present invention is not limited to these embodiments. The
present invention covers any substitutive, modified and equivalent
methods and schemes employed within the spirit and scope of the
present invention.
[0028] For making the public thoroughly understand the present
invention, the specific details are described in the following
preferred embodiment of the present invention, while those skilled
in the art can also completely understand the present invention
without the descriptions of these details.
[0029] The present invention is described in detail in the
following paragraphs with reference to the accompanied drawings by
way of examples. It should be explanatory that the accompanied
drawings are in a simplified form, employ the non-accurate
proportions and are only used for the purpose of conveniently and
clearly assisting the description of the embodiments of the present
invention.
[0030] As shown in FIG. 2, a circuit structure of the first
embodiment of the present invention is illustrated. An LED driving
circuit receives alternating current input, converts the input into
direct current with ripples and supplies power for an LED load. A
direct current power is connected to a positive end of the LED
load, and a negative end of the LED load is connected with a ripple
removing circuit of the present invention. In this embodiment, the
ripple removing circuit includes a regulation tube M01, a current
generating circuit U01, a current source I01, and a first capacitor
C02. The regulation tube M01 in this embodiment is a Negative
Channel-Metal-Oxide-Semiconductor (NMOS), the first end of the
regulation tube M01 is a drain electrode, the second end of the
regulation tube M01 is a source electrode, and the control end of
the regulation tube M01 is a grid electrode. The negative end of
the LED load is connected to the drain electrode (namely the first
end) of the regulation tube M01, and the source electrode (namely
the second end) of the regulation tube M01 is grounded. The current
generating circuit U01 is connected between the drain electrode and
the grid electrode (namely a control end) of the regulation tube
M01. The current source I01 and the first capacitor C02 are
connected in parallel and are connected between the grid electrode
of the regulation tube M01 and the ground. Take the LED as the load
for example for the description. The first capacitor C02 is
connected between the grid electrode of the regulation tube M01 and
the ground, and the first capacitor C02 and the current generating
circuit U01 forms a filter circuit. When the system is balanced or
after the system is in a steady state, the current i02 generated by
the current generating circuit U01 is equal to the current i01 of
the current source I01, and the time constant of the filter circuit
is far greater than the power frequency period. Therefore, a
voltage VC on the first capacitor C02 is approximately a direct
current (DC) voltage free of ripples, so that the current flowing
across the regulation tube M01 is approximately a direct current
free of ripples, thereby decreasing the current ripples going
across the LED load, and input current ripples are converted into
voltage ripples at the drain-source end of the regulation tube M01
by an input capacitor C01. The DC component of the voltage ripples
at the drain-source end of the regulation tube M01 can be
controlled by setting the value of the current i01 of the current
source I01. That is, the current generating circuit U01 generates
the current i02 according to the difference between a voltage VD
and the voltage VC. An average value of the current i02 is equal to
the current value of the current source I01, the larger the current
of the current source I01 is set, the greater the average value of
the current i02 converted based on the voltage difference is, and
the higher the voltage VD is. Accordingly, the DC component
regulation is achieved.
[0031] As shown in FIG. 3, a circuit structure of the second
embodiment of the present invention is illustrated. This embodiment
is improved based on the first embodiment, and the main difference
lies in that the current generating circuit U01 is defined. That
is, a second resistor R02 is adopted to serve as the current
generating circuit, and two ends of the current generating circuit
are connected for receiving the voltages VD and VC, respectively.
The current across the second resistor R02 depends on the voltage
difference between the voltages VD and VC, and accordingly the
current i02 is obtained. Other corresponding descriptions can refer
to the description of the first embodiment.
[0032] As shown in FIG. 4, a circuit structure of the third
embodiment of the present invention is illustrated. This embodiment
is improved based on the first embodiment and the second
embodiment, and the main difference lies in that a first resistor
R03 is added. One end of the first resistor R03 is connected with
the source electrode of the regulation tube M01 and the other end
of the first resistor R03 is grounded. Due to the fact that the
first resistor R03 is added, the ripple removing effect can be
improved. Although the current generating circuit U01 is also
defined as the second resistor R02 in this embodiment, it can also
be like the first embodiment in which the current generating
circuit is not limited. That is, other circuits except the second
resistor R02 can be adopted for implementation.
[0033] As shown in FIG. 5, a circuit structure of the fourth
embodiment of the present invention is illustrated. This embodiment
is improved based on the first embodiment, and the main difference
lies in that the output current i02 of the current generating
circuit U01 is not controlled according to the voltage difference
between the voltages VD and VC but is directly controlled by the
voltage VD, namely the voltage difference between the voltage VD
and the ground. Accordingly, the current generating circuit U01
needs connection to the ground. Wherein, the input end of the
current generating circuit is connected with the VD end and the
ground, and the current output end of the current generating
circuit is connected to the voltage VC. The current i02 generated
by the current generating circuit is in direct proportion to the
voltage between the voltage VD and the ground, namely i02=k1*VD.
During balance, i02=i01, wherein i02 is the average value of the
current i02, and the average value of the voltage VD
VD=i02/k1=i01/k1.
[0034] As shown in FIG. 6, an implementation mode of the current
generating circuit of the fourth embodiment of the present
invention is illustrated. The current generating circuit includes a
voltage-to-current conversion circuit and a current mirror module.
The input end of the voltage-to-current conversion circuit is
connected with the first end of the regulation tube, the other end
of the voltage-to-current conversion circuit is connected with the
current mirror module, and the output end of the current mirror
module is connected with a common end of the current source and the
first capacitor. Specifically, the voltage-to-current conversion
circuit includes an operational amplifier U20 and a switch tube
M21, the voltage VD is connected to the positive input end of the
operational amplifier U20, one end of the resistor R20 is connected
to the negative input end of the operational amplifier U20, and the
other end of the resistor R20 is grounded; the output end of the
operational amplifier U20 is connected to a control end of the
switch tube M21, a source electrode of the switch tube M21 is
connected to the negative input end of the operational amplifier,
namely the common end connected with the operational amplifier U20
and the resistor R20. A drain electrode of the switch tube M21 is
connected to the input end of the current mirror module consisting
of a switch tube M22 and a switch tube M23, and both the switch
tube M22 and the switch tube M23 are Positive Channel Metal Oxide
Semiconductor (PMOS). The output end of the current mirror module
is the output end of the current generating circuit. The result of
dividing the breadth length ratio of the M22 by the breadth length
ratio of the M23 is supposed to be k2, and the output current of
the current generating circuit is k2*VD/R20, namely k1=k2/R20.
Therefore, k1 can be obtained by selecting an appropriate
coefficient k2 and the resistor R20. Although the structure shown
in FIG. 6 is achieved based on the voltage VD serving as the
control voltage, the voltage difference between the voltages VD and
VC can also serve as the control voltage for achievement.
[0035] As shown in FIG. 7, a circuit structure of the fifth
embodiment of the present invention is illustrated. That is, this
embodiment can be improved based on all the above embodiments. An
operational amplifier U10 and a current sampling resistor R10 are
added. At the same time, the current sampling resistor R10 can also
play the effect of the first resistor R03 in FIG. 4, but a
corresponding resistance value can be varied. Therefore, the
current sampling resistor R10 in this embodiment can also be
defined as the first resistor in the claims. In other words, the
first resistor R03 in FIG. 4 can also simultaneously serve as the
sampling resistor.
[0036] The positive end of the first capacitor C02, namely the VC
end is connected to the positive input end of the operational
amplifier U10, the source electrode of the regulation tube M01 is
connected to the ground through the current sampling resistor R10.
The common end of the current sampling resistor R10 and the
regulation tube M01 is connected to the negative input end of the
operational amplifier U10, and the output end of the operational
amplifier U10 is connected to the grid electrode of the regulation
tube M01. The operational amplifier U10 and the current sampling
resistor R10 are added. Due to the fact that the voltage VC can be
approximately a DC voltage, The voltage on the current sampling
resistor R10 representing current flowing across the regulation
tube is equal to the voltage VC and is approximately the DC
voltage. That is, the current across the LED is approximately a
direct current, the ripple removing effect can be further
improved.
[0037] As shown in FIG. 8, a circuit structure of the sixth
embodiment of the present invention is illustrated. In the above
embodiments, the common end of the current generating circuit and
the current source I01 can be connected to the first capacitor C02
through the nonlinear regulation circuit U30. A detailed
description is given by adding the nonlinear regulation circuit U30
in the scheme recorded in FIG. 2 of the first embodiment.
[0038] The input end of the nonlinear regulation circuit is
connected with the common end of the current generating circuit and
the current source, and the output end of the nonlinear regulation
circuit is connected with the first capacitor. The charge or
discharge of the first capacitor C02 is regulated by adding the
nonlinear regulation circuit U30, and the value, approximate to a
valley bottom, of the voltage VD or the voltage difference between
the voltages VD and VC can be controlled to be a fixed value when
the input current ripples change, the ripple removing circuit can
always effectively remove the ripples. Further, a control value of
the voltage VD or VD-VC can be set as a smaller value so as to
reduce the loss of the regulation tube M01, such that this scheme
has a self-adaption function for the input current ripples.
[0039] One implementation mode of the nonlinear regulation circuit
is that when the current i02 generated by the current generating
circuit U01 is greater than the current i01 of the current source
I01, the charging current for the first capacitor C02 from the
nonlinear regulation circuit U30 is M*(i02-i01); when the current
i02 generated by the current generating circuit U01 is smaller than
the current i01 of the current source I01, the discharging current
for the first capacitor C02 from the nonlinear regulation circuit
U30 is N*(i01-i02). M and N may be integers or decimals, and the
value of M may be the same as or different from the value of N. N/M
is greater than or equal to 1. Due to the fact that charge and
discharge of the first capacitor C02 are balanced, when N/M is
greater than 1, the value smaller than the average value of the
current i02 but greater than the valley bottom value of the current
i02 is controlled to be equal to i01. The greater the N/M value is,
the more the value controlled to be equal to i01 is approximate to
the valley bottom value of the current i02; if the N/M value is
equal to 1, the average value of the current i02 is controlled to
be equal to i01. The advantage brought by the fact that the value,
approximate to the valley bottom, of the current i02 is controlled
to be equal to i01 is that since the waveforms of the current i02
reflect the waveforms of the voltage VD or the voltage difference
between the voltages VD and VC, the value, approximate to the
valley bottom, of the voltage VD or the voltage difference between
the VD and VC is controlled to be a fixed value. In other words,
during balance or in the steady state, on the premise that the
regulation tube M01 is ensured working in a saturation zone, the
voltage at the first end of the regulation tube M01 is lower, and
the energy loss of the regulation tube can be reduced.
[0040] As shown in FIG. 9, a schematic circuit diagram of one
implementation mode of the nonlinear regulation circuit is
illustrated. The input end VI of the nonlinear regulation circuit
U30 is connected with the common end of the current generating
circuit and the current source I01, and the output end of the
nonlinear regulation circuit U30 is connected with the first
capacitor C02. When the current i02 is greater than i01, a switch
K30 is switched on, a switch K31 is switched off, and the current
source with value of M*(i02-i01) charges the VC end; when the
current i02 is smaller than i01, the switch K31 is switched on, and
the current source with value of N*(i01-i02) discharges the VC.
[0041] In addition to this, although the above embodiments are
described and illustrated separately, regarding partial common
technologies, those ordinarily skilled in the art can substitute
and integrate the embodiments, and for the unclearly recorded
contents of any one of the embodiments, another recorded embodiment
can be referred to.
[0042] The above embodiments do not limit the protection scope of
the technical scheme. Any modification, equivalent alternation and
improvement employed under the spirit and principle of the
embodiments should be within the protection scope of the technical
scheme.
* * * * *