CN208353663U

CN208353663U - Light-coupled isolation PWM light adjusting circuit

Info

Publication number: CN208353663U
Application number: CN201820948024.3U
Authority: CN
Inventors: 罗斌
Original assignee: Shenzhen An Fu Te Technology Co Ltd
Current assignee: Shenzhen An Fu Te Technology Co Ltd
Priority date: 2018-06-20
Filing date: 2018-06-20
Publication date: 2019-01-08
Anticipated expiration: 2028-06-20

Abstract

The utility model discloses light-coupled isolation PWM light adjusting circuits, using the technological means of light-coupled isolation, circuit is designed, the PWM dim signal that more power supplys may be implemented does not interfere with each other power supply altogether, control power supply output achievees the purpose that light and extinguishes LED light source, has the advantages that system reliability is high.

Description

Light-coupled isolation PWM light adjusting circuit

Technical field

The utility model relates to PWM light adjusting circuit fields, and in particular, to light-coupled isolation PWM light adjusting circuit.

Background technique

PWM is pulse width adjustment signal, and PWM light modulation is to adjust output work by adjusting the width of pwm pulse signal Rate that is, lamplight brightness.With the raising that LED lamp intelligent control requires, the requirement of PWM light modulation is also higher and higher.It is general in the market It is exported all over the pwm signal ground wire and power supply used and shares ground wire.Pwm signal is generally generated by digital circuit, and digital circuit is anti-dry It is strong to disturb ability, power supply is analog circuit, and analog circuit anti-interference ability is weak, and power supply is easy to be interfered.The high failure rate of power supply In digital circuit, also power failure damages pwm signal generative circuit frequent occurrence.In the application system of high reliability, PWM letter It number is generated by programmable controller, programmable controller is very expensive, requires that PWM dim signal is wanted and isolated from power, is avoided It is damaged by power supply.

Provided herein is a kind of PWM light adjusting circuit of light-coupled isolation, it can control power supply output and reach and light and extinguish LED light The purpose in source successfully avoids the PWM dim signal of more power supplys from generating interference signal interference power altogether, also PWM is protected to believe It number is not damaged by power supply disturbance.

Utility model content

The purpose of this utility model is that in view of the above-mentioned problems, light-coupled isolation PWM light adjusting circuit is proposed, to realize more The PWM dim signal of power supply do not interfere with each other altogether, controls power supply output achievees the purpose that light and extinguishes LED light source, and having can The advantage high by property.

In order to achieve the above purposes, the technical solution adopted by the utility model is: light-coupled isolation PWM light adjusting circuit, it is main to wrap It includes:

The pin 1 of plug-in unit PWM, the plug-in unit PWM connect the pin 1 of isolation optocoupler U2, and the pin 2 of the plug-in unit PWM is logical The pin 2 of series resistance R4 connection isolation optocoupler U2 is crossed, the pin 3 of isolation optocoupler U2 is separately connected one end and the electricity of resistance R5 One end of R7 is hindered, the pin 4 of isolation optocoupler U2 is separately connected one end of resistance R1 and one end of resistance R6, and resistance R1's is another Auxiliary DC power supply VCC is terminated, the other end of resistance R6 is connected with the other end of resistance R7 and the lead-out wire of its tie point point Not Lian Jie the pole G of metal-oxide-semiconductor Q1 and one end of capacitor C2, the other end of capacitor C2 is separately connected the other end of resistance R5, metal-oxide-semiconductor The pole S of Q1 and GND, the pole D of metal-oxide-semiconductor Q1 pass through one end of series resistance R8 connection OTHER CONTROL circuit, OTHER Another termination GND of CONTROL circuit.

The advantageous effects of the utility model:

Light-coupled isolation PWM light adjusting circuit is designed circuit using the technological means of light-coupled isolation, is believed by pwm pulse Number isolation control power supply output achievees the purpose that light and extinguishes LED light source, and PWM count word signal ground and power supply is successfully avoided to simulate Ground bring hidden danger altogether, improves the reliability of system.

Other features and advantages of the utility model will illustrate in the following description, also, partly from specification In become apparent, or understood and implementing the utility model.

Below by drawings and examples, the technical solution of the utility model is described in further detail.

Detailed description of the invention

Attached drawing is used to provide a further understanding of the present invention, and constitutes part of specification, practical with this Novel embodiment is used to explain the utility model together, does not constitute limitations of the present invention.In the accompanying drawings:

Fig. 1 is light-coupled isolation PWM light adjusting circuit schematic diagram；

Fig. 2 is the schematic diagram of the specific implementation circuit of light-coupled isolation PWM light adjusting circuit.

Specific embodiment

It is illustrated below in conjunction with preferred embodiment of the attached drawing to the utility model, it should be understood that described herein excellent It selects embodiment to be only used for describing and explaining the present invention, is not used to limit the utility model.

As shown in Figure 1, light-coupled isolation PWM light adjusting circuit, specifically includes that plug-in unit PWM, the pin 1 of the plug-in unit PWM are connected The pin 1 of isolation optocoupler U2, the pin 2 of the plug-in unit PWM pass through the pin 2 of series resistance R4 connection isolation optocoupler U2, isolation The pin 3 of optocoupler U2 is separately connected one end of resistance R5 and one end of resistance R7, and the pin 4 of isolation optocoupler U2 is separately connected electricity Hinder one end of R1 and one end of resistance R6, the other end and electricity of another termination auxiliary DC power supply VCC of resistance R1, resistance R6 The other end of resistance R7 is connected and the lead-out wire of its tie point is separately connected the pole G of metal-oxide-semiconductor Q1 and one end of capacitor C2, capacitor The pole D that the other end of C2 is separately connected the other end of resistance R5, the pole S of metal-oxide-semiconductor Q1 and GND, metal-oxide-semiconductor Q1 passes through series resistance One end of R8 connection OTHER CONTROL circuit, another termination GND of OTHER CONTROL circuit.

U2 is the optocoupler that pwm signal is isolated, and R4 is the current-limiting resistance of pwm signal, when PWM+- interpolar has certain direct current When pressure, the LEDs ON of optocoupler shines, and generates electric current in the reception triode of optocoupler, and electric current flows through R1, R5, Pressure drop is generated on R1, R5, causes Q1 on and off.When R5 is much larger than R1, the limit is that R1 is 0 Europe, and R6 is much larger than R5+R7 When, the limit is R6 open circuit, does not have electric current in R5, and Q1 shutdown has electric current in R5 after optocoupler conducting, and Q1 is open-minded.When R5 is much smaller than R1, pole Limit is that R5 is zero, reasonably selects the resistance value of R1R6R7, and when optocoupler is not turned on, VCC assigns to certain voltage, Q1 conducting on R7. When optocoupler conducting, the upper voltage drop of R6R7 is low, Q1 shutdown.It can be seen that can choose Q1 by adjusting the resistance value of R1R5R6R7 The logic level of shutdown is opened, switch Q1 when switch Q1 or pwm signal are low level when pwm signal is high level.

OTHER CONTROL circuit in the block diagram of the right indicates to be turned off by low level control in regular tap power supply Power supply output or the circuit for reducing electric power output voltage.

As shown in Fig. 2, U1A is operational amplifier, U1A and peripheral circuit are that the common voltage error of regular tap power supply is put Big circuit.U3 is the isolation optocoupler between the primary and secondary of isolation control power supply, and R12 is current-limiting resistance.R3, C1 are feedback loop. The 3rd of U1A meets reference voltage source Vref by resistance R11, and the 2nd foot of U1A connects voltage sample circuit, and R2R8R10Q1 composition is defeated Voltage sample circuit out.When Q1 conducting, R8 is in parallel with R10, and electric power output voltage can increase.Switch Q1, can control power supply Output voltage switches between two voltages of height.High voltage lamp bead is bright, low-voltage setting to the conducting voltage lower than lamp bead, lamp bead With regard to extinguishing.

R8 is connected to the 3rd foot of amplifier, and when Q1 is not turned on, the 3rd foot voltage is equal to Vref, when Q1 conducting, is equivalent to R8 Other end ground connection, R11, R8 are divided, and voltage is equal to Vref in R8 institute component voltage on the 3rd foot, and the 3rd foot voltage reduces, output voltage Equal proportion reduces.Q1 opens the height closed and equally can control electric power output voltage.

Q1 can also control power supply chip, thorough power cutoff output.Power supply chip permitted Multifunctional foot can be by Q1 Control, power cutoff output, such as the end energization pins VCC of chip, soft start pin, under-voltage protection foot etc..

At least can achieve it is following the utility model has the advantages that

Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention, it is not limited to this Utility model, although the utility model is described in detail with reference to the foregoing embodiments, for those skilled in the art For, it is still possible to modify the technical solutions described in the foregoing embodiments, or to part of technical characteristic It is equivalently replaced.Within the spirit and principle of the utility model, any modification, equivalent replacement, improvement and so on, It should be included within the scope of protection of this utility model.

Claims

1. light-coupled isolation PWM light adjusting circuit, which is characterized in that the circuit includes:

Socket PWM, the pin 1 of the socket PWM are that pwm signal anode connects, and the pin 1 of socket PWM connects drawing for isolation optocoupler U2 Foot 1, the pin 2 of the socket PWM are PWM dim signal cathode, by the pin 2 of series resistance R4 connection isolation optocoupler U2, The pin 3 of isolation optocoupler U2 is separately connected one end of resistance R5 and one end of resistance R7, and the pin 4 of isolation optocoupler U2 connects respectively One end of connecting resistance R1 and one end of resistance R6, another termination auxiliary DC power supply VCC of resistance R1, the other end of resistance R6 It is connected with the other end of resistance R7 and the lead-out wire of its tie point is separately connected the pole G of metal-oxide-semiconductor Q1 and one end of capacitor C2, The pole D that the other end of capacitor C2 is separately connected the other end of resistance R5, the pole S of metal-oxide-semiconductor Q1 and GND, metal-oxide-semiconductor Q1 passes through series connection One end of resistance R8 connection OTHER CONTROL circuit, another termination GND of OTHERCONTROL circuit.