Background technology
LED(light emitting diode) light fixture is widely used in various views and the lighting field, light fixture for a plurality of LED formations, usually adopt at present DMX(Digital Multiplex, the multi-path digital transmission) 512 agreements output control signal is controlled, the DMX512 agreement is USITT(U.S. arenas technological associations) issue a kind of light control protocol, it has become the general standard agreement of country, applies to widely in the lamp light control system of light of stage, the illumination of building building landscape.
Data transmission method between DMX512 light control host-host protocol regulation dimmer and controlled device thereof comprises electrical characteristic, data format, Data Transport Protocol and connector type etc.The transfer of data of DMX512 agreement adopts 8 asynchronous serial transmission modes.The DMX512 field is by sequential delivery, each field by 1 start bit, 8 data bit, and two position of rests consist of.First field also comprises homing sequence before transmitting: reset signal, rear mark and initial code reset.Initial code divides non-zero initial code and zero initial code, 255 non-zero initial codes (decimal system 1~255) are used for expansion and use flexibly, it is typeless serial 8 bit informations that zero initial code is used for identifying follow-up field, effectively the DMX512 data field value is between the decimal system 0~255, and it is expressed as dimmer brightness degree data.Packet by zero initial code sign is the default data that sends in the DMX512 network, be reset signal, the rear mark that resets, zero initial code and DMX512 field consist of the DMX512 packet, n DMX512 field light modulation data of the 1st to n DMX512 passage of order correspondence successively in the packet.One or more DMX512 packets enter the DMX512 primary data link after by the EIA485 interface, and the signal on the primary data link is referred to as the DMX512 control signal.
Existing DMX512 lamp control system generally adopts bus-type or " daisy chain " connected mode, and both principles are similar, all is that each unit loads is connected with master controller by a main DMX512 data link.Master controller sends the DMX512 control signal.All lamp loads must be preset the address, after the matching addresses, could extract and process related data from the packet of receiving.The DMX512 packet comprises at most 512 fields, therefore default address must be in the 1-512 scope value.Simultaneously, each unit loads can comprise one or more DMX512 passages.As: the lamp string that a plurality of unit loads consist of, each unit loads contain 3 passages with the LED lamp of control RGB three looks, and the default address of unit loads is 1,4,7 ..., N, default address is 1 unit loads reception and extracts the 1st, the light modulation data of 2,3 DMX512 passages, default address are 2 unit loads reception and extract the 4th, the light modulation data of 5,6 DMX512 passages.The like, each unit loads is obtained the dimming control signal that address default with it is complementary, to realize that LED sends required lighting effects.
So present DMX512 lamp light control system all needs the default address of unit loads.Fig. 1 is the theory diagram of LED lamp control system in the prior art.Default address generally configures by mode manually or automatically.Manual configuration generally is to unit loads the address to be set one by one by write address device of manual operation; Automatically configuration generally is to set up an auxiliary serial-port between controller and unit loads, sends the address by controller instruction is set.The default address of manual configuration must be corresponding with link position, and connected mode is fixed, and default address and the easy entanglement of link position cause mistake to connect in the connection procedure.Autoconfigured address needs specific hardware system to realize, its versatility is not high, and has increased a DMX data link, makes connection and the complicated structure of control system.
Be understandable that, the statement of this part only provides the background information relevant with the utility model, may consist of or not consist of so-called prior art.
Summary of the invention
Technical problem to be solved in the utility model is need to be to the default address of LED lamp load for LED lamp control system in the prior art, so that LED light fixture connected mode is fixed and baroque defective, provide a kind of LED lamp control system, so that the connected mode of LED light fixture and control system is flexible and control system is simple in structure.
The technical scheme that its technical problem that solves the utility model adopts provides a kind of LED lamp control system, and it comprises: several constant pressure sources and several trunk modules; The input of each trunk module is connected with a constant pressure source, and its output is electrically connected one group of LED light fixture, and several trunk modules connect by serial mode successively from the output of DMX512 control signal; Described trunk module is used for decoding and intercepting DMX512 control signal and drives connected LED light fixture according to the control signal that intercepts, and remaining DMX512 control signal is forwarded to the next stage trunk module.
In above-mentioned LED lamp control system, each trunk module comprises: level shifting circuit is used for the DMX512 control signal is converted to the TTL signal, and remaining DMX512 control signal is forwarded to next trunk module from differential signal; The controller that is electrically connected with level shifting circuit, be used for the TTL signal decoding and intercept decoded signal, will intercept after remaining DMX512 control signal be forwarded to described level shifting circuit, reach the signal that intercepting is obtained and carry out pulse-width modulation; Be connected in the switching tube between controller and the LED light fixture, be used for the break-make according to the pulse-width signal control LED light fixture of controller output; The constant-current drive circuit that is connected with the LED light fixture is used for constant pressure source is converted to the constant-current source that supplies the driving LED light fixture; And DC converting circuit, be used for voltage step-down that constant pressure source is provided with to level shifting circuit, controller, and constant-current drive circuit DC power supply is provided, described DC converting circuit simultaneously with level shifting circuit, controller, and constant-current drive circuit link to each other.
In above-mentioned LED lamp control system, described trunk module also comprises the anti-phase drive circuit that is connected between controller and the switching tube, and anti-phase drive circuit is electrically connected with described DC converting circuit simultaneously.
In above-mentioned LED lamp control system, described anti-phase drive circuit comprises diode D1, field effect transistor Q1, triode Q2, reaches resistance R 1; Wherein, the grid of the positive pole of diode D1 and field effect transistor Q1 connects the output of controller simultaneously, the negative pole of diode D1 links to each other through the base stage of resistance R 1 with triode Q2, the emitter of triode Q2 connects the output of DC converting circuit, the source ground of field effect transistor Q1, the collector electrode of triode Q2 link to each other with the drain electrode of field effect transistor Q1 and connect simultaneously the input of switching tube.
In above-mentioned LED lamp control system, described field effect transistor Q1 is the NMOS pipe, and described triode Q2 is positive-negative-positive.
In above-mentioned LED lamp control system, described level shifting circuit is the RS485 level translator.
In above-mentioned LED lamp control system, described switching tube is field effect transistor.
In above-mentioned LED lamp control system, also comprise the feedback circuit that is connected in the operating state that is used for feedback LED light fixture between LED light fixture and the constant-current drive circuit.
In above-mentioned LED lamp control system, described feedback circuit is sampling resistor.
In above-mentioned LED lamp control system, described constant-current drive circuit comprises the LM3402HV chip.
In the LED lamp control system that the utility model provides, it adopts a plurality of trunk modules to connect successively by serial mode from the output of DMX512 control signal, and the trunk module that connects by serial mode intercepts and transmits the DMX512 control signal, so the trunk module by the constant pressure source power supply can intercept and transmit each LED light fixture that DMX512 controls signal to needs correspondence dynamically, it can be regulated dynamically and transmit the DMX512 control signal and send the lighting effects that need with driving LED, thereby do not need each LED lamp load is preset separately the address, therefore a plurality of LED light fixtures need not connect by fixed form, its connected mode is more flexible, and whole control system need not increase accessory channel again, and it is simple in structure.
Embodiment
Clearer for technical problem, technical scheme and beneficial effect that the utility model is solved, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
The LED lamp control system that the utility model provides is mainly used in controlling the light fixture that a plurality of LED lamps consist of, and it adopts a plurality of trunk modules and intercepts and transmit the DMX512 control signal by mode connected in series, need not be to the default address of LED light fixture thereby realize.
To shown in Figure 7, the LED lamp control system that the utility model provides comprises several constant pressure sources 1 and several trunk modules 2 referring to Fig. 2.The input of each trunk module is connected with a constant pressure source 1, and the output of this trunk module 2 is electrically connected a LED light fixture.Constant pressure source is mainly used in civil power or other alternating current commonly used are converted to the direct current of voltage stabilization, and then gives that various piece provides power supply in the whole control system.Trunk module is used for the DMX512 control signal is decoded, a decoded DMX512 control signal intercepting part is used for driving connected LED light fixture, and this trunk module is forwarded to the next stage trunk module with remaining DMX512 control signal, be that current trunk module is transmitted to next trunk module with remaining DMX512 control signal, until the DMX512 control signal has been intercepted or be forwarded to last trunk module.Several trunk modules connect successively by serial mode from the output of output DMX512 control signal that (the DMX control signal is produced by the DMX master controller, the DMX master controller is well known to those skilled in the art), be that first trunk module connects the DMX512 control signal in N the trunk module, and N-1 remaining trunk module connected successively with first trunk module.
The constant pressure source that each trunk module and being attached thereto connects and LED light fixture consist of a unit loads, and the control system that the utility model provides is mainly for the LED lamp string that is comprised of a plurality of LED light fixtures.An above-mentioned LED light fixture can also can consist of for a plurality of LED lamps for a LED lamp, the utility model mainly for be the situation that is consisted of a LED light fixture by three LED of RGB etc., can be controlled by control signal the luminous situation of three lamps of RGB, thereby make a LED light fixture can whole mix out the light of different colours.
The situation that consists of a LED light fixture in conjunction with three lamps of RGB is described below the operation principle of the control system that the utility model provides: the DMX512 controller signals by reset signal, zero initial code, and multichannel light modulation data form, it can expand the DMX512 data packet length, transmission makes the unit loads quantity of series connection unrestricted more than the light modulation data of 512 passages.The DMX512 control signal comprises the packet of N passage light modulation data, each trunk module decoding prime DMX512 control signal and the front 3 passage light modulation data of intercepting.After intercepting front 3 passage light modulation data, the light modulation data of surplus (N-3) individual passage in the packet, and the 4th channel data becomes the 1st channel data in the current data packet in the former packet.And remaining DM512 control signal was forwarded to next trunk module after current trunk module will intercept.Particularly, each unit loads contains 3 passages, and concerning the DMX512 packet that a upper equipment sends, the address of active cell load always is defaulted as 1, and its 3 contained passages are front 3 passages of packet.The control signal of front 3 passages that current trunk module will intercept is carried out pulse-width modulation, and with the ON time of change switching tube, and the DMX512 after the current trunk module forwarding intercepting controls signal to the trunk module in the next unit loads.Then current trunk module can directly be used for the DMX512 control signal of its intercepting to regulate the luminous situation of connected LED light fixture, be that the DMX512 control signal is for dynamic, its capable of dynamic is regulated each LED light fixture, thereby need not be to the default address of each LED light fixture.
Referring to embodiment illustrated in fig. 3, each trunk module comprises: level shifting circuit is used for the DMX512 control signal is converted to the TTL signal and remaining DMX512 control signal is forwarded to next trunk module from differential signal; Controller (MCU among Fig. 3), be used for the TTL signal decoding and intercept decoded signal, will intercept after remaining DMX512 control signal be forwarded to level shifting circuit, and the signal that will intercept carry out pulse-width modulation; Switching tube is used for the break-make according to the pulse-width signal control LED light fixture of controller output; Constant-current drive circuit is used for constant pressure source is converted to the constant-current source that supplies the driving LED light fixture; And DC converting circuit (being the DC-DC reduction voltage circuit), be used for and will power to level shifting circuit and controller after the constant pressure source step-down.So it is the actuable switch pipe that the DMX512 control signal after controller will intercept is carried out after the pulse-width modulation, and then the luminous situation of control LED light fixture.In Fig. 3, MCU exports the respectively LED lamp of three passages of corresponding control RGB of three road pulse-width signals.Preferably, trunk module also comprises the anti-phase drive circuit that is connected between controller and the switching tube, and anti-phase drive circuit is electrically connected with described DC converting circuit simultaneously.Be that DC converting circuit is given anti-phase drive circuitry after with the constant pressure source step-down, and then anti-phase drive circuit carry out the pulse-width signal of MCU output anti-phase with better driving switch pipe.
Preferably, described level shifting circuit is the RS485 level translator, and it can carry out level conversion more fast and effectively, and above-mentioned switching tube is preferably field effect transistor (being metal-oxide-semiconductor), in order to can respond faster the driving signal of its prime.Also be provided with the feedback circuit for feedback LED light fixture operating state between each LED light fixture and the constant-current drive circuit, for example with operating current, voltage and the temperature feedback of LED light fixture to constant-current drive circuit, and then make the different constant current of the adaptive adjustment output of constant-current drive circuit.Preferably, feedback circuit is sampling resistor, and constant-current drive circuit is according to the precision of the constant current of its output of voltage capable of regulating of the LED light fixture of sampling resistor collection.More preferably, constant-current drive circuit comprises the peripheral circuit (referring to Fig. 5) of LM3402HV chip and cooperation thereof, and it can provide constant-current source so that the required driving power of LED to be provided fast and accurately.What deserves to be explained is, when the lamp load that drives when constant-current drive circuit is the different lamp of three of RGB, LM3402HV chip periphery components and parts can be done and locally improve to export different constant-current sources, and then drive different LED lamps.
60VDC is the voltage of constant pressure source output among Fig. 3.In this embodiment, described switching tube is specially metal-oxide-semiconductor.Each trunk module comprises DC-DC reduction voltage circuit, RS485 level translator, MCU, 3 tunnel anti-phase drive circuits, 3 metal-oxide-semiconductors and 3 road independent efficiently high power LED constant-current driving circuits.In this embodiment, the RGB three-color LED light needs three tunnel different constant-current drive circuits to drive (this is well known to those skilled in the art, and does not repeat them here).The DC-DC reduction voltage circuit is converted into appropriate level with the constant pressure source output voltage, and one the tunnel makes anti-phase drive circuit power supply, and one the tunnel to RS485 level translator and MCU power supply.The RS485 level translator is converted to the TTL signal with the DMX512 control signal on the DMX data link by differential signal, and is connected to the universal asynchronous serial input mouth of MCU.The course of work of MCU roughly is described below in conjunction with Fig. 6: the MCU serial ports enters the serial ports interruption after receiving the DMX512 control signal, and it enters the serial ports interrupt handling routine.At first determine whether input DMX512 reset signal, judge namely whether it is the DMX512 control signal; If not, then skip to DMX-OUT, if, then determine whether the zero initial code of DMX512, judge namely whether it is dim signal, then transmit if not zero initial code and skip to DMX-OUT, if judge it is zero initial code, then determine whether the light modulation data of reference format, then directly transmit if not serial ports input data, if then intercept front 3 light modulation data, MCU changes respectively the duty ratio of 3 PWM mouths according to front 3 light modulation data, exports 3 road pwm signals and will intercept rear remaining DMX512 control signal to be forwarded to next trunk module.
Refer again to Fig. 4, it is the preferred embodiment of anti-phase drive circuit.It comprises diode D1, field effect transistor Q1, triode Q2, reaches resistance R 1.The grid of the positive pole of diode D1 and field effect transistor Q1 connects the output of controller simultaneously, the negative pole of diode D1 links to each other through the base stage of resistance R 1 with triode Q2, the emitter of triode Q2 connects the output of DC converting circuit, the source ground of field effect transistor Q1, the collector electrode of triode Q2 link to each other with the drain electrode of field effect transistor Q1 and connect simultaneously the input of switching tube as the output of anti-phase drive circuit.Preferably, described field effect transistor Q1 is the NMOS pipe, and described triode Q2 is positive-negative-positive.Its operation principle is as follows: when the input termination high level of anti-phase drive circuit, when for example connecing the 5V high level signal, because the voltage of the 8.5V that exports for the DC-DC reduction voltage circuit that the emitter of triode Q2 connects, so the time diode D1 cut-off, triode Q2 emitter can not conducting, and field effect transistor Q1 conducting, therefore the output of anti-phase drive circuit is equivalent to ground connection, its output OUT is low level; When input input 0V low level signal, the path conducting that the emitter of triode Q2 pipe, resistance R 1 and diode D1 consist of, not conducting of field effect transistor Q1 this moment therefore output OUT end is the 8.5V logic high, and can be exported the drive current up to 110mA.Because the switching frequency of the ON time * PWM of the operating current of LED lamp=constant current drive current * LED string, ON time is by the when frequency decision of duty of PWM ripple.Therefore the operating current of LED string and light adjusting grade n can realize 256 grades of high linearity light adjustings near high linear relationship.Therefore this anti-phase drive circuit both can also improve drive level and the drive current of pwm signal with level inversion, and then drive the external power metal-oxide-semiconductor and carry out the high-speed switch response, to realize the high linearity light adjusting (referring to shown in Figure 7) to the LED lamp.
Compared with prior art, the control system that provides of the utility model mainly has the following advantages:
1, it adopts unique mode connected in series in conjunction with trunk module, and each unit loads is pressed serial connection sequence intercepting light modulation data automatically, and is forwarded to the next unit load.It need not to the default address of each LED light fixture, make a plurality of LED light fixture networkings connect summary, and it be simple in structure, cost is lower.
2, it adopts the directly anti-phase drive circuit of driving power metal-oxide-semiconductor.Use this anti-phase drive circuit can improve drive level and the drive current of pwm signal, and then drive the external power metal-oxide-semiconductor and carry out the high-speed switch response, to realize the high linearity light adjusting to the LED lamp.
3, constant-current drive circuit can be adjusted the ON time of constant-current driven chip accurately in conjunction with feedback circuit, and with automatic adaptation set with constant current value, it can guarantee constant current accuracy.
In description of the present utility model, unless otherwise prescribed and limit, need to prove, term " installation ", " linking to each other ", " connection " should be done broad understanding, for example, can be mechanical connection or electrical connection, also can be the connection of two element internals, can be directly to link to each other, and also can indirectly link to each other by intermediary, for the ordinary skill in the art, can understand as the case may be the concrete meaning of above-mentioned term.
The above only is preferred embodiment of the present utility model; not in order to limit the utility model; all any modifications of within spirit of the present utility model and principle, doing, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.