CN211183931U

CN211183931U - Positive and negative connection high-voltage isolation digital input circuit

Info

Publication number: CN211183931U
Application number: CN201922493982.3U
Authority: CN
Inventors: 方正
Original assignee: Wuhan Zhongchuang Rongke Polytron Technologies Inc
Current assignee: Wuhan Zhongchuang Rongke Polytron Technologies Inc
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-08-04
Anticipated expiration: 2029-12-31

Abstract

The utility model relates to a positive and negative connection high voltage isolation digital input circuit, which comprises a voltage dividing circuit, a positive and negative connection modulation circuit and an isolation circuit, wherein the positive and negative connection modulation circuit receives an input signal and rectifies the current direction of the input signal; the voltage division circuit is connected with the positive and negative connection modulation circuit to reduce the voltage of an input signal and input the reduced voltage signal to the isolation circuit, and the isolation circuit is an IOS1212 chip to isolate the signal input from the voltage division circuit and the signal output from the isolation circuit. The input end of the positive and negative connection high-voltage isolation digital input circuit can be positively or reversely connected and is adaptive to the high-voltage level while isolating signals.

Description

Positive and negative connection high-voltage isolation digital input circuit

Technical Field

The utility model relates to a digital isolation input circuit field especially relates to a positive and negative connects high pressure to keep apart digital input circuit.

Background

The digital isolation technology is commonly used in the field bus of the industrial network environment and other places with severe environment. The digital isolation circuit is mainly used for transmitting digital signals and switching value signals. The main purpose of using the isolation circuit is to isolate the front and rear stage circuits, prevent mutual interference, and perform level conversion.

The conventional digital isolator such as a photoelectric coupler transmits data to a light detector at the other end of an isolation gate by using light emitted by L ED, L ED is turned on when the logic is in a high state, L ED is turned off when the logic is in a low state, the input voltage born by the photoelectric coupler generally does not exceed 40V, but 48V or even 110V high level is used in industrial application, the photoelectric coupler cannot be used at the moment, meanwhile, the photoelectric coupler has high power consumption, is easy to age and influenced by temperature, provides limited data rate, is generally lower than 1Mbps if the photoelectric coupler is a high-speed photoelectric coupler, is generally only suitable for circuits with 5V or 3.3V level, and does not meet the field electrical characteristics.

SUMMERY OF THE UTILITY MODEL

For overcoming the problem that keeps apart digital input circuit and can not the transposition and only the low level of adaptation, the utility model provides a positive and negative connects high voltage and keeps apart digital input circuit.

The technical scheme of the utility model for solving the technical problem provides a positive and negative connects high voltage and keeps apart digital input circuit, positive and negative connects high voltage and keeps apart digital input circuit and includes bleeder circuit, positive and negative connects modulation circuit and isolating circuit, positive and negative connects modulation circuit and accepts input signal to with the current direction rectification of input signal; the voltage division circuit is connected with the positive and negative connection modulation circuit to reduce the voltage of an input signal and input the reduced voltage signal to the isolation circuit, and the isolation circuit is an IOS1212 chip to isolate the signal input from the voltage division circuit and the signal output from the isolation circuit.

Compared with the prior art, the utility model provides a positive and negative connects high pressure to keep apart digital input circuit has following advantage:

through the rectifier bridge and the divider resistor, the input end can be connected in a positive and negative way, and the risk of operation error is reduced; and the power supply entering the isolation circuit is reduced, so that the input end can adapt to the high-voltage level, and thus more levels can be adapted, namely the input end can adapt to the high-voltage level while being connected in a positive and negative mode.

The above description of the present invention does not limit the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the scope of the claims of the present invention.

Drawings

Fig. 1 is a schematic block diagram of a positive-negative connection high-voltage isolation digital input circuit according to a first embodiment of the present invention;

FIG. 2 is a circuit diagram of the voltage divider circuit and the positive-negative modulation circuit of FIG. 1;

FIG. 3 is a circuit diagram of the isolation circuit of FIG. 1;

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1-3, the present invention provides a positive and negative connection high voltage isolation digital input circuit 10, which comprises a voltage divider circuit 20, a positive and negative connection modulation circuit 30 and an isolation circuit 40, wherein the positive and negative connection modulation circuit 30 rectifies the current of the input end into one direction, so that the input end can be adjusted to be the same direction after passing through the positive and negative connection modulation circuit 20 no matter the input end is connected or connected reversely, thereby avoiding the situation of burning out the input end due to reverse connection.

The voltage divider circuit 20 limits the maximum current input at the input terminal, so as to reduce the voltage entering the positive and negative connection high voltage isolation digital input circuit 10, so that the voltage at the input terminal can be increased, and further, the 110V level input can be compatible.

The isolation circuit 40 isolates the input signal and the output signal to prevent interference between the input signal and the output signal.

Specifically, the forward/reverse connection modulation circuit 30 includes a rectifier bridge formed by four diodes and a capacitor C connected in parallel with the rectifier bridge, the four diodes are respectively a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4, and the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 are connected in series. After passing through the rectifier bridge, the direction of the input current is always unchanged no matter the current is in positive connection or in reverse connection. The capacitor C is used for adjusting voltage filtering of the rectifier bridge, the voltage directly rectified by the rectifier bridge is not stable enough, and the voltage flowing through the rectifier bridge is filtered through the parallel capacitor C to obtain stable voltage.

The voltage divider circuit 20 is composed of a first voltage divider resistor R1 and a second voltage divider resistor R5, and the first voltage divider resistor R1 and the second voltage divider resistor R5 are connected to the positive-negative modulation circuit 30, wherein the first voltage divider resistor R1 is connected to the output terminal of the rectifier bridge and is connected in series with the output terminal, and the second voltage divider resistor R5 is connected to the input terminal of the rectifier bridge and is connected in series with the output terminal. By communicating the first diode D1 and the third diode D3 or the second diode D2 and the fourth diode D4, after the current can pass, the resistance of the first voltage divider resistor R1 or the second voltage divider resistor R5 is adjusted to reduce the voltage entering the positive and negative connection high voltage isolation digital input circuit 10, so that the voltage of the input end can be increased.

The isolation circuit 40, which is an I SO1212 chip, is powered by a power supply of DC5V, and isolates the input end and the output end of the signal, SO as to prevent the signals at the input end and the output end from interfering with each other.

Further, the isolation circuit 40 provides two input channels, SENSE0/I N0 and SENSE1/I N1, respectively, with isolation between the two input channels (see fig. 3).

When the positive and negative connection high-voltage isolation digital input circuit 10 is used, an input end is input from D l n1_1 or D l p _1, rectified in the positive and negative connection modulation circuit 30, then the voltage is reduced by the voltage division circuit 20, and finally the voltage enters the isolation circuit 40 to realize signal isolation.

Compared with the prior art, the utility model provides a positive and negative high pressure isolation digital input circuit that connects has following advantage:

Claims

1. A positive and negative connection high-voltage isolation digital input circuit is characterized in that:

the positive and negative connection high-voltage isolation digital input circuit comprises a voltage division circuit, a positive and negative connection modulation circuit and an isolation circuit, wherein the positive and negative connection modulation circuit receives an input signal and rectifies the current direction of the input signal; the voltage division circuit is connected with the positive and negative connection modulation circuit to reduce the voltage of an input signal and input the reduced voltage signal to the isolation circuit, and the isolation circuit is an ISO1212 chip to isolate the signal input from the voltage division circuit and the signal output from the isolation circuit.

2. The positive-negative connection high-voltage isolation digital input circuit of claim 1, wherein:

the positive and negative connection modulation circuit comprises a rectifier bridge formed by connecting a first diode, a second diode, a third diode and a fourth diode in series and a capacitor connected with the rectifier bridge in parallel.

3. The positive-negative connection high-voltage isolation digital input circuit of claim 2, wherein:

the voltage division circuit comprises a first voltage division resistor and a second voltage division resistor, and the first voltage division resistor and the second voltage division resistor are connected to the rectifier bridge.

4. A positive-negative connection high-voltage isolation digital input circuit according to claim 3, wherein:

the second voltage-dividing resistor is arranged at a signal input section of the rectifier bridge, and the first voltage-dividing resistor is arranged at a digital output end of the rectifier bridge.

5. The positive-negative connection high-voltage isolation digital input circuit of claim 1, wherein:

the isolation circuit has two mutually independent input channels.