The linear LED drive circuit of full voltage
Technical field
The invention belongs to electronic drive circuit control technology field, and in particular to a kind of linear LED drive circuit of full voltage.
Give a kind of suitable 120VAC and 220VAC and input general linear LED drive schemes.
Background technology
LED is as a kind of efficient new light sources, since with long lifespan, energy consumption is low, energy conservation and environmental protection, is just being widely used in each
Field illuminates.Lighting for LED needs drive circuit to be driven.However, since the load characteristic of LED causes, conventional linear LED
Type of drive is lost very greatly under high voltages, and lumen is inadequate at lower voltages.It can only work in very narrow voltage domain.Can not be real
The high-low pressure of existing invariable power is general.The present invention reduces energy loss while realizing that high low input is compatible, ensure that
Lumen so that the reliability of product has basic guarantee under conditions of full voltage application.
The content of the invention
In order to solve the above-mentioned technical problem, the present invention proposes a kind of linear LED drive circuit of full voltage.
In order to achieve the above object, technical scheme is as follows:
The linear LED drive circuit of full voltage, including:
Shaping circuit, for the alternating current full wave of input to be rectified into quasi sine voltage;
First load circuit, includes the LED of one or more series connection;
Second load circuit, includes the LED of one or more series connection;
First voltage sample circuit, it is connected between the V+ and V- of the quasi sine voltage of input, and first voltage is adopted
Sample circuit is used to gather the first control voltage, and the first control voltage is used for the turn-on and turn-off for controlling voltage control circuit;
Current limit circuit, it connects with the first load circuit, and current limit circuit flows through the first load electricity for limitation
Current value on road;
Voltage control circuit, its with connect after the first load circuit and current limit circuit connect again, and the electricity
Press control circuit in parallel with the second load circuit by on-off circuit;
Voltage controls current limit circuit, it is electric by on-off circuit and the first load circuit after connecting and current limit
Road is in parallel;
Second voltage sample circuit, it is in parallel with voltage control current limit circuit, for gathering the second control voltage, the
Two control voltages are used for the turn-on and turn-off for controlling voltage control current limit circuit, and voltage controls the electric current of current limit circuit
Limits value reduces with the increase of the second control voltage;
When the quasi sine average voltage of input is relatively low, the first control voltage of first voltage sample circuit collection and the
Second control voltage of two voltage sampling circuits collection is relatively low, voltage control circuit conducting, voltage control current limit circuit
Conducting, on-off circuit shut-off, the first load circuit and the second load circuit parallel operation;
When the quasi sine average voltage of input is higher, the first control voltage of first voltage sample circuit collection and the
Second control voltage of two voltage sampling circuits collection is higher, voltage control circuit shut-off, voltage control current limit circuit
Shut-off, on-off circuit conducting, the first load circuit and the second load circuit tandem working.
The present invention provides a kind of linear LED drive circuit of full voltage, is the standard after alternating current full wave rectification between V+ and V-
Sinusoidal voltage.
When the quasi sine average voltage of input is relatively low, voltage control circuit conducting, voltage control current limit circuit
It is operated in constant current state, on-off circuit shut-off, the first load circuit and the second load circuit parallel operation.In the quasi sine of input
When average voltage is higher, voltage control circuit shut-off, voltage control current limit circuit shut-off, on-off circuit conducting, first
Load circuit and the second load circuit tandem working.Meanwhile this topological structure to realize that first is negative automatically when inputting high-low pressure
Carry circuit and the second load circuit connect and parallel connection switching, power invariability, avoids load circuit in quasi sine instantaneous voltage
Power is inadequate when relatively low, and power is bigger than normal in high voltage.The present invention realizes linear LED driver in input ac voltage
Under 120VAC and 220VAC, it can work normally.
The present invention realizes the driving of LED using simple component, it effectively reduces cost.
Based on the above technical solutions, following improvement can also be done:
As preferable scheme, on-off circuit includes:The cathode of diode D1, diode D1 respectively with current limit circuit
Connected with voltage control circuit, the anode of diode D1 is connected with voltage control current limit circuit respectively.
Using the above preferred scheme, simple in structure, cost is low.
As preferable scheme, voltage control circuit is realized by voltage control demand limiter, voltage control current limit
The current limit value of device reduces with the increase of the first control voltage.
Using the above preferred scheme, superior performance.
As preferable scheme, voltage control demand limiter includes:The voltage controlled current source I1 and current limliting being connected in series are adopted
Sample resistance R3, the first control voltage can control the size of voltage controlled current source I1 output currents.
Using the above preferred scheme, the security performance of circuit is high, and control effect is good.
As preferable scheme, voltage control circuit is realized by voltage controlled resistance circuit, voltage controlled resistance circuit
Resistance value with first control voltage increase and increase.
Using the above preferred scheme, simple in structure, cost is low.
As preferable scheme, voltage controlled resistance circuit includes:Nmos pass transistor MN101, nmos pass transistor MN102 with
And resistance R4;
Source electrode of the source electrode of MN101 respectively with quasi sine the voltage V- and MN102 of input is connected, its grid and the first control
Voltage connects, and its drain electrode is connected with the grid and resistance R4 of MN102 respectively;
Source electrode of the source electrode of MN102 respectively with quasi sine the voltage V- and MN101 of input is connected, its grid respectively with
The drain electrode of MN101 is connected with resistance R4, and its cathode of drain electrode respectively with the first load circuit and diode D1 is connected;
Resistance R4 one end is connected with the drain electrode of MN101 and the grid of MN102 respectively, its another termination internal electric source Vdc.
Using the above preferred scheme, it is simple in structure, it is low using simple component, cost.
As preferable scheme, voltage control current limit circuit includes:Voltage controlled current source I2 and current limliting sampling resistor R5,
Voltage controlled current source I2 and current limliting sampling resistor R5 series connection, and connect after voltage controlled current source I2 and current limliting sampling resistor R5 again with string
The first load circuit and current limit circuit after connection is in parallel.
Using the above preferred scheme, it is simple in structure.
As preferable scheme, voltage control current limit circuit includes:Voltage controlled current source I2 and current limliting sampling resistor R5,
Voltage controlled current source I2 with connect after the first load circuit and current limit circuit it is in parallel, current limliting sampling resistor R5 is loaded with second
Circuit connected in series.
Using the above preferred scheme, the security performance of circuit is high, has current switching defencive function.
As preferable scheme, first voltage sample circuit includes the resistance R31 and resistance R32 being connected in series, and resistance
Output voltage is the first control voltage between R31 and resistance R32.
Using the above preferred scheme, simple in structure, the performance of circuit is more stable.
As preferable scheme, second voltage sample circuit includes the resistance R61 and resistance R62 being connected in series, and resistance
Output voltage is the second control voltage between R61 and resistance R62.
Using the above preferred scheme, simple in structure, the performance of circuit is more stable.
Brief description of the drawings
Fig. 1 is the module map of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Fig. 2 is one of circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Fig. 3 controls current limit value (I_VCS) in demand limiter to be controlled with first for voltage provided in an embodiment of the present invention
The change curve of voltage (Vc1) processed.
Fig. 4 is the two of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Fig. 5 is the three of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Fig. 6 is the resistance value (R-VCS) of voltage controlled resistance circuit provided in an embodiment of the present invention with the first control voltage
(Vc1) change curve.
Fig. 7 is the four of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Fig. 8 is current limit value (I_VCCC) in voltage provided in an embodiment of the present invention control current limit circuit with second
Control the change curve of voltage (Vc2).
Fig. 9 is the five of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Figure 10 is the six of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Figure 11 is the seven of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Figure 12 is the eight of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Figure 13 is the nine of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Figure 14 is the ten of the circuit diagram of the linear LED drive circuit of full voltage provided in an embodiment of the present invention.
Wherein:1st, the first load circuit, the 2, second load circuit, 3, first voltage sample circuit, 4, voltage control circuit,
5th, voltage control current limit circuit, 6, second voltage sample circuit, 7, current limit circuit, 8, shaping circuit, 9, switch electricity
Road.
Embodiment
The preferred embodiment that the invention will now be described in detail with reference to the accompanying drawings.
In order to reach the purpose of the present invention, in some of embodiments of the linear LED drive circuit of full voltage, such as Fig. 1 institutes
Show, the linear LED drive circuit of full voltage includes:
The linear LED drive circuit of full voltage includes:
Shaping circuit 8, for the alternating current full wave of input to be rectified into quasi sine voltage;
First load circuit 1, includes the LED1 of multiple series connection;
Second load circuit 2, includes the LED2 of multiple series connection;
First voltage sample circuit 3, it is connected between the V+ and V- of the quasi sine voltage of input, and first voltage is adopted
Sample circuit 3 is used to gather the first conducting and passes of the control voltage Vc1, the first control voltage Vc1 for controlling voltage control circuit 4
It is disconnected;
Current limit circuit 7, it connects with the first load circuit 1, and current limit circuit 7 flows through the first load for limitation
Current value on circuit 1;
Voltage control circuit 4, its with connect after the first load circuit 1 and current limit circuit 7 connect again, and should
Voltage control circuit 4 is in parallel with the second load circuit 2 by on-off circuit 9;
Voltage controls current limit circuit 5, it passes through on-off circuit 9 and the first load circuit 1 after connecting and electric current limit
Circuit 7 processed is in parallel;
Second voltage sample circuit 6, it is in parallel with voltage control current limit circuit 5, for gathering the second control voltage
Vc2, the second control voltage Vc2 are used for the turn-on and turn-off for controlling voltage control current limit circuit 5, voltage control current limit
The current limit value I_VCCC of circuit 5 reduces with the increase of the second control voltage Vc2, as shown in Figure 8;
When the quasi sine average voltage of input is relatively low, the first control voltage Vc1 of the collection of first voltage sample circuit 3
The the second control voltage Vc2 gathered with second voltage sample circuit 6 is relatively low, and voltage control circuit 4 turns on, voltage control electric current
Limiting circuit 5 turns on, and on-off circuit 9 turns off, 2 parallel operation of the first load circuit 1 and the second load circuit;
When the quasi sine average voltage of input is higher, the first control voltage Vc1 of the collection of first voltage sample circuit 3
The the second control voltage Vc2 gathered with second voltage sample circuit 6 is higher, and voltage control circuit 4 turns off, voltage control electric current
Limiting circuit 5 turns off, and on-off circuit 9 turns on, 2 tandem working of the first load circuit 1 and the second load circuit.
As shown in Fig. 2, wherein, on-off circuit 9 includes:The cathode of diode D1, diode D1 are electric with current limit respectively
Road 7 and voltage control circuit 4 connect, and the anode of diode D1 is connected with voltage control current limit circuit 5 respectively.
The present invention provides a kind of linear LED drive circuit of full voltage, is the standard after alternating current full wave rectification between V+ and V-
Sinusoidal voltage.
When the quasi sine average voltage of input is relatively low, voltage control circuit 4 turns on, voltage control current limit circuit
5 are operated in constant current state, and on-off circuit 9 turns off, 2 parallel operation of the first load circuit 1 and the second load circuit.In the standard of input
When sinusoidal voltage average value is higher, voltage control circuit 4 turns off, and voltage control current limit circuit 5 turns off, and on-off circuit 9 is led
It is logical, 2 tandem working of the first load circuit 1 and the second load circuit.Meanwhile this topological structure to input it is automatically real during high-low pressure
Existing first load circuit 1 and the second load circuit 2 connect and parallel connection switching, power invariability, avoids load circuit in quasi sine
Power is inadequate when instantaneous voltage is relatively low, and power is bigger than normal in high voltage.
The present invention realizes the driving of LED using simple component, it effectively reduces cost.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, voltage control circuit 4 is realized by voltage control demand limiter, as shown in figure 3, voltage controls electric current
The current limit value I_VCS of limiter reduces with the increase of the first control voltage Vc1.
As shown in figure 4, voltage control demand limiter includes:The voltage controlled current source I1 and current limliting sampling resistor being connected in series
R3, the first control voltage Vc1 can control the size of voltage controlled current source I1 output currents.
Using the above preferred scheme, the security performance of circuit is high, and control effect is good.Fig. 5 controls electric current limit for voltage
The particular circuit configurations of device processed.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, voltage control circuit 4 is realized by voltage controlled resistance circuit, as shown in fig. 6, voltage controlled resistance
The resistance value R_VCS of circuit increases with the increase of the first control voltage Vc1.
As shown in fig. 7, voltage controlled resistance circuit includes:Nmos pass transistor MN101, nmos pass transistor MN102 and electricity
Hinder R4;
Source electrode of the source electrode of MN101 respectively with quasi sine the voltage V- and MN102 of input is connected, its grid and the first control
Voltage Vc1 connections, and its drain electrode is connected with the grid and resistance R4 of MN102 respectively;
Source electrode of the source electrode of MN102 respectively with quasi sine the voltage V- and MN101 of input is connected, its grid respectively with
The drain electrode of MN101 is connected with resistance R4, and its cathode of drain electrode respectively with the first load circuit 1 and diode D1 is connected;
Resistance R4 one end is connected with the drain electrode of MN101 and the grid of MN102 respectively, its another termination internal electric source Vdc.
Using the above preferred scheme, it is simple in structure, it is low using simple component, cost.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, as shown in figure 9, voltage control current limit circuit 5 includes:Voltage controlled current source I2 and current limliting sampling electricity
Hinder R5, voltage controlled current source I2 and current limliting sampling resistor R5 series connection, and voltage controlled current source I2 and current limliting sampling resistor R5 after series connection
Again with connect after the first load circuit 1 and current limit circuit 7 it is in parallel.
Using the above preferred scheme, it is simple in structure.Figure 10 is the physical circuit knot that voltage controls current limit circuit 5
Structure.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, as shown in figure 11, voltage control current limit circuit 5 includes:Voltage controlled current source I2 and current limliting sampling electricity
Hinder R5, voltage controlled current source I2 and the first load circuit 1 after connect and the parallel connection of current limit circuit 7, current limliting sampling resistor R5 and
Second load circuit 2 is connected.
Using the above preferred scheme, the security performance of circuit is high, has current switching defencive function.Figure 12 is voltage control
The particular circuit configurations of current limit circuit 5 processed.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, as shown in Fig. 2, first voltage sample circuit 3 includes the resistance R31 and resistance R32 being connected in series, and
Output voltage is the first control voltage Vc1 between resistance R31 and resistance R32.
Using the above preferred scheme, simple in structure, the performance of circuit is more stable.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, as shown in Fig. 2, second voltage sample circuit 6 includes the resistance R61 and resistance R62 being connected in series, and
Output voltage is the second control voltage Vc2 between resistance R61 and resistance R62.
Using the above preferred scheme, simple in structure, the performance of circuit is more stable.
In order to further optimize the implementation result of the present invention, in other embodiment, remaining feature technology phase
Together, difference is, as shown in figure 13, after the first load circuit 1 is connected with current limit circuit 7, then it is electric with voltage control
Road 4 is connected, and current limit circuit 7 is used to limit the current value flowed through on the first load circuit 1.Current limit circuit 7 includes:It is permanent
Stream source I3 and current limliting sampling resistor R6.
Using the above preferred scheme, the performance of circuit is more stable.Figure 14 is the physical circuit knot of current limit circuit 7
Structure.
For the preferred embodiment of the present invention, it is noted that for those of ordinary skill in the art, do not taking off
On the premise of conceiving from the invention, various modifications and improvements can be made, these belong to protection scope of the present invention.