CN218547336U - DALI isolation communication circuit - Google Patents

Abstract

The utility model relates to the technical field of communication, in particular to a DALI isolation communication circuit, which comprises a DALI bus, a bridge rectifier circuit, a constant current circuit, a voltage stabilizing circuit, a signal isolation receiving circuit, a signal isolation transmitting circuit and a Micro Control Unit (MCU); and the bridge rectifier circuit is used for enabling the input signal of the DALI bus not to be divided into positive and negative. This DALI keeps apart communication circuit, adopt optoelectronic coupler U1 and optoelectronic coupler U2's setting respectively through signal isolation receiving circuit and signal isolation transmitting circuit, make its inside linear opto-coupler that is the photoelectric triode, so the rising of output is down along the time than longer, utilize its 0.6V turn-on voltage to come the waveform of positive input through increasing PNP triode Q3 again, the signal of sending the bus is through adopting field effect transistor Q4's setting, come more positive waveform wave, and play optoelectronic coupler U1 and optoelectronic coupler U2 of circuit isolation and all use the linear opto-coupler most commonly used, come reduce cost.

Description

DALI isolation communication circuit

Technical Field

The utility model relates to the field of communication technology, specifically a DALI keeps apart communication circuit.

Background

The DALI communication circuit converts signals on a bus and signals between an MCU (microprogrammed control unit) into signals, and the circuit can work in a duplex state to meet the requirement of controlling lighting equipment by a user, wherein the DALI bus communication needs to pay attention when in use, and needs to prevent the user from mistakenly connecting an AC (alternating current) input to a DALI dimming line, so that high-voltage intrusion protection is needed; meanwhile, the DALI bus needs to be isolated, and other equipment or personnel can be damaged when high-voltage connection is wrong; in order to prevent MCU detection failure, rising and falling edges of a waveform need to be steep when a DALI bus communicates; when the DALI bus works normally, the current needs to be less than 2mA; when the DALI bus is connected with a signal line, the characteristics of a positive electrode, a negative electrode and the like do not need to be distinguished.

However, the prior art methods are various, and problems of complex circuits, multiple internal devices and large temperature drift exist, so that the success rates of possible communication of products at different temperatures in the use process are different, meanwhile, because the DALI bus usually needs to be constructed on a construction site, operators are difficult to avoid wrong connection, and when the operators access an AC input line into the DALI bus, the risk that most of equipment is damaged is caused.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

Not enough to prior art, the utility model provides a DALI keeps apart communication circuit has solved the problem that proposes in the above-mentioned background art.

(II) technical scheme

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes: a DALI isolation communication circuit comprises a DALI bus, a bridge rectifier circuit, a constant current circuit, a voltage stabilizing circuit, a signal isolation receiving circuit, a signal isolation transmitting circuit and a Micro Control Unit (MCU);

the bridge rectifier circuit is used for enabling an input signal of a DALI bus not to be divided into positive and negative;

the constant current circuit is used for keeping the circuit constant current and protecting the circuit from being damaged when high voltage invades;

the voltage stabilizing circuit is used for stabilizing voltage;

the signal isolation receiving circuit is used for receiving high and low levels;

and the signal isolation transmitting circuit is used for carrying out high-low level conversion control on a transmitting signal of the micro control unit MCU.

Optionally, the bridge rectifier circuit adopts a rectifier bridge D2 formed by 4 diodes inside.

Optionally, the constant current circuit includes a PNP triode Q1, a PNP triode Q2, a resistor R6, and a resistor R5, the PNP triode Q1 is connected in series with the resistor R6, and the PNP triode Q2 is connected in series with the resistor R5.

Optionally, the voltage stabilizing circuit includes a freewheeling diode D1 and a capacitor C1, where the freewheeling diode D1 and the capacitor C1 are connected in parallel.

Optionally, the signal isolation receiving circuit includes a resistor R1, a resistor R2, a resistor R3, a PNP triode Q3, and a photoelectric coupler U1, wherein one end of the resistor R3 is connected in series with one of the output ends of the photoelectric coupler U1.

Optionally, the signal isolation transmitting circuit includes a resistor R7, a resistor R8, a field effect transistor Q4, and a photoelectric coupler U2, the resistor R7 and the resistor R8 are connected in series, and the resistor R7 is connected in series with the photoelectric coupler U2.

(III) advantageous effects

The utility model provides a DALI keeps apart communication circuit possesses following beneficial effect:

1. this DALI keeps apart communication circuit, adopt optoelectronic coupler U1 and optoelectronic coupler U2's setting respectively through signal isolation receiving circuit and signal isolation transmitting circuit, make its inside linear opto-coupler that is the photoelectric triode, so the rising of output is down along the time than longer, utilize its 0.6V turn-on voltage to come the waveform of positive input through increasing PNP triode Q3 again, the signal of sending the bus is through the setting that adopts field effect transistor Q4, come more positive waveform, and play optoelectronic coupler U1 and optoelectronic coupler U2 of circuit isolation and all use the linear opto-coupler most commonly used, when coming reduce cost, the dependable performance, the security is high.

2. This DALI keeps apart communication circuit can increase the high voltage endurance of this circuit through the voltage value who chooses PNP triode Q1 and rectifier bridge D2 to protection equipment, this circuit is whole simple moreover, and it is less to adopt the device, possesses the advantage that the fault rate is low.

Drawings

Fig. 1 is a schematic block diagram of a communication circuit according to the present invention;

fig. 2 is a schematic diagram of the communication circuit of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

Referring to fig. 1 to 2, the present invention provides a technical solution: a DALI isolation communication circuit comprises a DALI bus, a bridge rectifier circuit, a constant current circuit, a voltage stabilizing circuit, a signal isolation receiving circuit, a signal isolation transmitting circuit and a Micro Control Unit (MCU); the bridge rectifier circuit is used for enabling an input signal of the DALI bus not to be divided into positive and negative; the constant current circuit is used for keeping the circuit constant current and protecting the circuit from being damaged when high voltage invades; the voltage stabilizing circuit is used for stabilizing voltage; the signal isolation receiving circuit is used for receiving high and low levels; the signal isolation transmitting circuit is used for carrying out high-low level conversion control on a transmitting signal of the micro control unit MCU;

the bridge rectifier circuit adopts a rectifier bridge D2 consisting of 4 diodes inside, so that whether the input of a pin 1 and a pin 3 of the rectifier bridge D2 is an alternating current signal or a direct current signal, the signals can be converted into a pin 2 to be output to be high level, and the output of the pin 4 is low level, therefore, when a DALI bus is connected, the output end of the rectifier bridge D2 can fixedly output high level at the pin 2, and the function that the input signal of the DALI bus does not need to be divided into positive and negative is realized;

the constant current circuit comprises a PNP triode Q1, a PNP triode Q2, a resistor R6 and a resistor R5, wherein the PNP triode Q1 is connected with the resistor R6 in series, the PNP triode Q2 is connected with the resistor R5 in series, the PNP triode Q2 and the resistor R6 can form a current detection function, when the current flowing through the resistor R6 reaches 2mA, about 0.6V voltage can be generated on the resistor R6, through the setting of the PNP triode Q1 and the PNP triode Q2, when the voltage Vb is smaller than the Ve voltage 0.6V, the collector output voltage of the PNP triode Q2 can rise and rise to the Vb of the PNP triode Q1, the output current of the PNP triode Q1 can fall, and meanwhile, the PNP triode Q1 is connected with the resistor R6 in series, the current of the resistor R6 is reduced, otherwise, the working modes are opposite, and the constant current process is completed in one cycle;

the constant current circuit also has a function of protecting the circuit from being damaged when a high voltage is intruded by improving the withstand voltage of the PNP transistor Q1 and the resistor R5, for example: protection when 220VAC access needs to be prevented, the voltage of 220V rectified by a rectifier bridge D2 can be calculated as follows: 220 × 1.414=311v, so the PNP transistor Q1 can be a PNP transistor of 400V;

the voltage stabilizing circuit comprises a freewheeling diode D1 and a capacitor C1, the freewheeling diode D1 and the capacitor C1 are connected in parallel, when the DALI bus is at a high level, voltage passes through the input end of a constant current circuit with a photoelectric coupler U1 to charge the capacitor C1, the freewheeling diode D1 has a parallel voltage stabilizing function, when the voltage of the capacitor C1 is equal to the clamping voltage of the freewheeling diode D1, the voltage can be stabilized, and when a signal is sent, electric energy can be provided for a field effect transistor Q4;

the signal isolation receiving circuit comprises a resistor R1, a resistor R2, a resistor R3, a PNP triode Q3 and a photoelectric coupler U1, wherein one end of the resistor R3 is connected with one output end of the photoelectric coupler U1 in series, when a DALI bus is high level, the output of a pin 3 of the photoelectric coupler U1 is high level, voltage can be divided by the resistor R3 and the resistor R2 to reach the base electrode of the PNP triode Q3, when the voltage reaches 0.6V, the PNP triode Q3 is switched on, the voltage of DA-RX at the resistor R1 is pulled down to be low level from VCC, the work of receiving the high level stage is completed, when the DALI bus is low level, the output of the pin 3 of the photoelectric coupler U1 is low level, the PNP triode Q3 is cut off, the DA-RX level is high level, the work of receiving the low level is completed, the resistor R2 accelerates the PNP triode Q3 to be cut off, so that the PNP triode Q3 can be calibrated at the rising edge when a received waveform, and the probability of detection of the micro control unit is reduced;

the signal isolation transmitting circuit comprises a resistor R7, a resistor R8, a field effect transistor Q4 and a photoelectric coupler U2, the resistor R7 and the resistor R8 are connected in series, the resistor R7 is connected in series with the photoelectric coupler U2, when a signal transmitted by the MCU is isolated and output through the photoelectric coupler U2, 3 legs of the MCU can output a high level, the high level is divided by the resistor R7 and the resistor R8 to reach a control electrode of the field effect transistor Q4, the field effect transistor Q4 is conducted, the output end of the rectifier diode D2 is short-circuited, and therefore the DALI bus level is conducted to be a low level, and when the low level is transmitted, the principle is opposite.

Above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the design of the present invention, equivalent replacement or change should be covered within the protection scope of the present invention.

Claims (6)

1. A DALI isolation communication circuit is characterized by comprising a DALI bus, a bridge rectifier circuit, a constant current circuit, a voltage stabilizing circuit, a signal isolation receiving circuit, a signal isolation transmitting circuit and a Micro Control Unit (MCU);

the bridge rectifier circuit is used for enabling an input signal of the DALI bus not to be divided into positive and negative polarities;

the constant current circuit is used for keeping the circuit constant current and protecting the circuit from being damaged when high voltage invades;

the voltage stabilizing circuit is used for stabilizing voltage;

the signal isolation receiving circuit is used for receiving high and low levels;

and the signal isolation transmitting circuit is used for carrying out high-low level conversion control on a transmitting signal of the micro control unit MCU.

2. A DALI isolated communication circuit as claimed in claim 1, wherein: the bridge rectifier circuit adopts a rectifier bridge D2 formed by 4 diodes inside.

3. The DALI isolated communication circuit as claimed in claim 1, wherein: the constant current circuit comprises a PNP triode Q1, a PNP triode Q2, a resistor R6 and a resistor R5, wherein the PNP triode Q1 and the resistor R6 are connected in series, and the PNP triode Q2 and the resistor R5 are connected in series.

4. The DALI isolated communication circuit as claimed in claim 1, wherein: the voltage stabilizing circuit comprises a freewheeling diode D1 and a capacitor C1, wherein the freewheeling diode D1 and the capacitor C1 are connected in parallel.

5. The DALI isolated communication circuit as claimed in claim 1, wherein: the signal isolation receiving circuit comprises a resistor R1, a resistor R2, a resistor R3, a PNP triode Q3 and a photoelectric coupler U1, wherein one end of the resistor R3 is connected with one output end of the photoelectric coupler U1 in series.

6. The DALI isolated communication circuit as claimed in claim 1, wherein: the signal isolation transmitting circuit comprises a resistor R7, a resistor R8, a field effect transistor Q4 and a photoelectric coupler U2, wherein the resistor R7 and the resistor R8 are connected in series, and the resistor R7 and the photoelectric coupler U2 are connected in series.

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