RU2522861C1 - Optoelectronic relay - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: optoelectronic relay includes first LED and a matrix of serial photodiodes connected optically to it; discharge device containing resistor; discharge acceleration devices with n-MOS and p-MOS transistors, two photodiodes and capacitor; protection device including LED shunted by a resistor, and phototransistor; and switching device with an n-MOS transistor.

EFFECT: possible current limitation in an optoelectronic relay, enhanced reliability.

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Description

The invention relates to the field of pulse technology and can be used in switching devices with galvanic isolation.

Known electronic switching relay with transformer isolation (RF patent No. 2375816 C1, H03K 17/00), containing the first and second electronic key on a DMOJI transistor, a pulse generator, a pulse transformer having a primary and secondary windings, the first and second rectifier diodes, current-sensing resistor , zener diode, first and second current-limiting resistors, first and second discharge resistors.

The well-known electronic switching relay with transformer isolation has a galvanic isolation of inputs and outputs made on a pulse transformer having primary and secondary windings, a switching device made on the first and second electronic switches on OMOH transistors.

Known electronic switching relay with transformer isolation has the following disadvantages.

1. The lack of current limiting function of the switched circuit.

2. The complexity of the control scheme.

3. The inability to implement the device in an integrated version due to the use of a transformer.

Known electronic fuse (patent No. 2356161 C9, H03K 17/00, H02H 7/00) containing two transistors and three resistors.

A well-known electronic fuse has a current limiting function. The disadvantage of an electronic fuse is the lack of galvanic isolation of inputs and outputs.

Known power switch on the MOS transistor (RF patent No. 2396706 C1, H03K 17/567), containing a transformer, transistors of the same conductivity, collector-emitter junctions which are shunted by diodes in the locking direction, and the base-emitter junctions - resistors, the collector of one of the transistors connected to the gate of an MOS transistor. the emitters of the transistors are connected directly, and the collector of the other transistor is connected to the beginning of the secondary winding of the transformer, the end of which is directly connected to the source of the MOS transistor, the additional secondary winding of the transformer is connected to the bases of the transistors, the beginning of the additional winding is connected to the base of the transistor, the collector of which is connected to the beginning of the secondary transformer windings, additional resistor, diode and bipolar transistor of similar conductivity of an MOS transistor, the first output d additional resistor is connected to the source of the MOS transistor and to the base of the additional transistor, the collector of which through the additional diode in the conducting direction is connected to the gate of the MOS transistor, the second output of the additional resistor is connected to the emitter of the additional transistor and the key output.

Known power switch on the MOS transistor has the following disadvantages.

1. To control the MOS transistor, a voltage is required that consists of the threshold voltage for turning on the transistor and the voltage for compensating for the drop on the additional resistor.

2. The presence of negative feedback due to the voltage drop across the additional resistor when the load current does not yet exceed the threshold value of the current limit.

3. The complexity of the circuit, requiring AC control.

4. The inability to implement the device in an integrated design due to the use of a transformer.

5. Low reliability.

Known optoelectronic relay (RF patent No. 2163417 C1, H03K 17/78, H03K 17/00) is a prototype.

Known optoelectronic relay containing an LED and an optically connected matrix of photodiodes in series, a switching device, a discharge device, a discharge accelerator device, made to improve the dynamic characteristics of the optoelectronic relay. The disadvantage of the optoelectronic relay is the lack of current limiting function of the switched circuit.

The aim of the invention is the implementation of the function of limiting the current in the optoelectronic relay, increasing the reliability of the device.

This goal is achieved by the fact that in the optoelectronic relay containing the first LED and an optically connected matrix of series-connected photodiodes, a switching device, a discharge device, the first and second conclusions of which are connected respectively to the positive and negative terminals of the matrix of series-connected photodiodes, and the third and fourth conclusions respectively to the first and second inputs of the switching device, the second output of which is the second output of the optoelectronic relay, and the inputs The electron-beam relays are the anode and cathode of the first LED, the discharge acceleration device optically coupled to the first LED and made on n-MOS and p-MOS transistors, the first and second photodiodes and capacitor, the drain of the n-MOS transistor, the gate of the p-MOS transistor, and the anode of the first the photodiode of which is connected to the first input of the switching device, the source of the n-MOS transistor, the negative lining of the capacitor and the anode of the second photodiode are connected to the second input of the switching device, the cathode of the first photodiode is connected to positive With the capacitor lining and the source of the r-MOS transistor, the drain of which is connected to the gate of the n-MOS transistor and the cathode of the second photodiode, a protective device is additionally introduced, consisting of a second LED shunted by an additional resistor and an optically connected phototransistor, the collector of the phototransistor is connected to the first the input of the switching device, and the emitter with the second input of the switching device, the cathode of the second LED and the first output of the additional resistor are connected to the first output of the comm utilization device, and the anode of the second LED and the second output of the additional resistor are the first output of the optoelectronic relay.

The drawing shows a schematic circuit diagram of the proposed optoelectronic relay, while in the drawing and further in the text are indicated:

1 - the first input of the optoelectronic relay:

2 - the second input of the optoelectronic relay;

3 - LED;

4 - matrix of series-connected photodiodes;

5 - the first resistor;

6 - the first photodiode;

7 - capacitor;

8 - p-MOS transistor;

9 - the second photodiode;

10 - the first n-MOS transistor;

11 - phototransistor;

12 - second LED;

13 - second resistor;

14 - second n-MOS transistor;

15 - the first output of the optoelectronic relay;

16 - the second output of the optoelectronic relay.

The optoelectronic relay is as follows.

The optoelectronic relay comprises a first LED 3 and an optically connected matrix of series-connected photodiodes 4, a switching device KU. made on the second n-MOS transistor 14, the protective ultrasound device made on the phototransistor 11, the second LED 12 and the second resistor 13, the discharge device UR made on the first resistor 5, the first and second conclusions of which are connected respectively to the positive and negative terminals of the matrix in series included photodiodes 4, the gate and source of the second n-MOS transistor 14 are connected respectively to the first and second terminals of the first resistor 5, the drain of the n-MOS transistor is connected to the cathode of the second LED 12 and the first output ohm of the second resistor 13 and is the first output of the switching device KU, the anode of the second LED 12 is connected to the second output of the second resistor 13 and is the first output of the optoelectronic relay 15, and the source of the second n-MOS transistor 14 is the second output of the switching device and the second output of the optoelectronic relay 16 wherein the first 1 and second 2 inputs of the optoelectronic relay are, respectively, the anode and cathode of the first LED 3, which is optically coupled to an acceleration discharge acceleration device made in the first n-MOS trans resistor 10 and p-MOS transistor 8, first 6 and second 9 photodiodes and capacitor 7, the drain of the first n-MOS transistor 10, the gate of the p-MOS transistor 8 and the anode of the first photodiode 6 are connected to the gate of the second n-MOS transistor 14, the source of the first The n-MOS transistor 10, the negative lining of the capacitor 7 and the anode of the second photodiode 9 are connected to the source of the second n-MOS transistor 14, the cathode of the first photodiode 6 is connected to the positive lining of the capacitor 7 and the source of the p-MOS transistor 8, the drain of which is connected to the gate of the first n MOS transistor 10 and the cathode of the second todioda 9, the collector and emitter of the phototransistor 11 are connected respectively to the gate and source of the second n-MOS transistor 14.

Optoelectronic relay operates as follows.

When a control signal is supplied to the first 1 and second 2 inputs of the optoelectronic relay, the first LED 3 emits photons, while the array of photodiodes 4 connected in series generates a photocurrent charging the input capacitance of the second n-MOS transistor 14 to the photo-emf voltage, which leads to a change in the state of the optoelectronic output the relay is turned off to on, and to turn on the second n-MOS transistor 14, it is only necessary to exceed the threshold voltage level for turning on the transistor and no additional voltage is required for I compensate for the fall on an additional resistor, which reduces the number of photodiodes in the matrix of series-connected photodiodes 4 and, therefore, increase the overall reliability of the optoelectronic relay. The CRM discharge accelerator is optically coupled to the first LED 3, and the capacitor 7 is charged through the first photodiode 6 to a voltage close to the photo-emf voltage generated by the array of series-connected photodiodes 4, and the gate of the first n-MOS transistor 10 is fully charged through the second photodiode 9. When this first n-MOS transistor 10 and p-MOS transistor 8 are securely closed and do not affect the charge process of the input capacitance of the second n-MOS transistor 14.

As long as the voltage drop across the second resistor 13 when the load current flows through it does not exceed the value that ensures the conductive state of the second LED 12, the second n-MOS transistor 14 operates without restriction. As soon as the second LED 12 begins to emit photons, the phototransistor 11 begins to open, while decreasing the conductivity of the channel of the second n-MOS transistor 14. When the load current reaches the specified level, the voltage _{V of the emitter base of the} phototransistor 11 will be such that it will open and translate the second n -MOS transistor 14 to cutoff mode.

When the control signal is switched off at the first and second inputs of the optoelectronic relay 1 and 2, the emission of LED 3 and, as a result, the generation of a photocurrent in the optically connected matrix of series-connected photodiodes 4. The input capacitance of the second n-MOS transistor 14 through the first resistor 5 of the discharge device The SD starts to discharge, and the second n-MOS transistor 14 is locked.

As the first LED 3, an optically coupled matrix of series-connected photodiodes 4 and the first resistor 5, a photovoltaic cell TLP591B f can be used. Toshiba, as a second LED 12 and an optically coupled phototransistor 11 - optocoupler TLP281B f. Toshiba, as the second n-MOS transistor - 1RFL014 f. International Rectifier, as the second resistor RC0805JR-0711RL YAGEO. Also, the claimed optoelectronic relay can be performed in an integral design.

Claims (1)

An optoelectronic relay containing a first LED and an optically connected matrix of series-connected photodiodes, a switching device, a discharge device, the first and second terminals of which are connected to the positive and negative terminals of the matrix of series-connected photodiodes, and the third and fourth terminals, respectively, to the first and second the inputs of the switching device, the second output of which is the second output of the optoelectronic relay, and the inputs of the optoelectronic relay are the anode and the method of the first LED, a discharge acceleration device optically coupled to the first LED made on n-MOS and p-MOS transistors, the first and second photodiodes and a capacitor, the drain of the n-MOS transistor, the gate of the p-MOS transistor and the anode of the first photodiode are connected to the first the input of the switching device, the source of the n-MOS transistor, the negative capacitor plate and the anode of the second photodiode are connected to the second input of the switching device, the cathode of the first photodiode is connected to the positive capacitor plate and the source p-MOS transistor, the drain of which is connected to the gate of the n-MOS transistor and the cathode of the second photodiode, characterized in that a protective device is introduced into the optoelectronic relay circuit, consisting of a second LED shunted by an additional resistor and a phototransistor optically coupled to it, and the collector of the phototransistor is connected with the first input of the switching device, and the emitter with the second input of the switching device, the cathode of the second LED and the first output of the additional resistor are connected to the first output of the commutator a measuring device, and the anode of the second LED and the second output of the additional resistor are the first output of the optoelectronic relay.