CN210839357U

CN210839357U - Isolated power supply

Info

Publication number: CN210839357U
Application number: CN201922180583.1U
Authority: CN
Inventors: 张家瑞
Original assignee: Strongled Lighting Systems Suzhou Co ltd
Current assignee: Grand Canyon Lighting System Suzhou Co ltd
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2020-06-23
Anticipated expiration: 2029-12-09

Abstract

The application provides an isolation power supply, which comprises an isolation transformer and a switch circuit. And the first input end and the second input end of the isolation transformer are both used for being electrically connected with a power supply. The first output end of the isolation transformer outputs a first voltage. And the second output end of the isolation transformer outputs a second voltage. And the first end of the switch circuit is respectively and electrically connected with the third output end and the fourth output end of the isolation transformer. The second terminal of the switching circuit is grounded. And the control end of the switch circuit is used for receiving a trigger control signal. This application is kept apart power (insert isolation transformer elementary) and RS485 control end power (insert isolation transformer secondary) through isolation transformer to with the switching circuit cooperation, change elementary DC voltage into alternating voltage, make energy coupling to secondary, thereby appear when unusual when RS485 control end power, can not cause the influence to the main power supply.

Description

Isolated power supply

Technical Field

The present application relates to the field of power supply technology, and more particularly, to an isolated power supply.

Background

In small electronic devices such as lamps, power is often supplied by an ac power supply method. Meanwhile, the supply voltage required for small electronic devices is very small, and it is conventional to convert the dc power supplied from the dc power supply into ac power that can be applied to the electronic devices through a transformer.

However, this power supply method cannot achieve the effect of power isolation. I.e. when the equipment connected to the secondary of the transformer fails, it will have an impact on the main power supply. Namely, the existing power supply mode has potential safety hazard and easily damages the main power supply.

SUMMERY OF THE UTILITY MODEL

Therefore, an isolation power supply is needed to be provided aiming at the problems that the existing power supply mode has potential safety hazards and the main power supply is easy to damage.

An isolated power supply comprising:

the first input end and the second input end of the isolation transformer are both used for being electrically connected with a power supply, the first output end of the isolation transformer outputs a first voltage, and the second output end of the isolation transformer outputs a second voltage; and

and the first end of the switch circuit is electrically connected with the third output end and the fourth output end of the isolation transformer respectively, the second end of the switch circuit is grounded, and the control end of the switch circuit is used for receiving a trigger control signal.

In one embodiment, the switching circuit includes:

and the drain electrode of the MOS tube is respectively electrically connected with the third output end and the fourth output end of the isolation transformer, the source electrode of the MOS tube is grounded, and the grid electrode of the MOS tube is used for receiving the trigger control signal.

In one embodiment, the isolated power supply further comprises:

and the trigger control signal is input to the grid electrode of the MOS tube through the first capacitor.

In one embodiment, the isolated power supply further comprises:

and the first end of the protection circuit is electrically connected with the control end of the switch circuit, and the second end of the protection circuit is grounded.

In one embodiment, the protection circuit includes:

a first diode, a cathode of which is electrically connected with a control end of the switch circuit, and an anode of which is grounded; and

and the first end of the resistor is respectively and electrically connected with the cathode of the first diode and the control end of the switch circuit, and the second end of the resistor is grounded.

In one embodiment, the isolated power supply further comprises:

and the input end of the first rectifying and filtering circuit is electrically connected with the first output end of the isolation transformer, and the output end of the first rectifying and filtering circuit is used for outputting the first voltage.

In one embodiment, the first rectifying and filtering circuit includes:

the anode of the second diode is electrically connected with the first output end of the isolation transformer, and the cathode of the second diode is used for outputting the first voltage; and

and a first end of the second capacitor is electrically connected with the cathode of the second diode, and a second end of the second capacitor is grounded.

In one embodiment, the isolated power supply further comprises:

and the input end of the second rectifying and filtering circuit is electrically connected with the second output end of the isolation transformer, and the output end of the second rectifying and filtering circuit is used for outputting the second voltage.

In one embodiment, the second rectifying and filtering circuit includes:

the anode of the third diode is electrically connected with the second output end of the isolation transformer, and the cathode of the third diode is used for outputting the second voltage; and

and a first end of the third capacitor is electrically connected with the cathode of the third diode, and a second end of the third capacitor is grounded.

In one embodiment, the isolated power supply further comprises:

and a first end of the fourth capacitor is electrically connected with the power supply, the first input end and the second input end of the isolation transformer respectively, and a second end of the fourth capacitor is grounded.

Compared with the prior art, the isolation power supply isolates the power supply (connected into the primary side of the isolation transformer) and the RS485 control end power supply (connected into the secondary side of the isolation transformer) through the isolation transformer, and the isolation power supply is matched with the switch circuit to convert the primary direct-current voltage into the alternating-current voltage, so that the energy is coupled to the secondary side through the isolation transformer, and when the RS485 control end power supply is abnormal, the main power supply cannot be influenced. Meanwhile, an interference signal of the RS485 control end is isolated from entering the main power supply, and the stability of the system is improved.

Drawings

FIG. 1 is a schematic block diagram of an isolated power supply provided by an embodiment of the present application;

fig. 2 is a circuit diagram of an isolated power supply according to an embodiment of the present disclosure.

10 isolated power supply

100 isolation transformer

101 power supply

200 switching circuit

210 MOS tube

220 first capacitor

300 protective circuit

310 first diode

320 resistor

400 first rectifying and filtering circuit

410 second diode

420 second capacitance

500 second rectifying and filtering circuit

510 third diode

520 third capacitance

600 fourth capacitor

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, an embodiment of the present application provides an isolated power supply 10, including: an isolation transformer 100 and a switching circuit 200. The first input terminal and the second input terminal of the isolation transformer 100 are both used for electrically connecting to a power supply 101. A first output terminal of the isolation transformer 100 outputs a first voltage. The second output terminal of the isolation transformer 100 outputs a second voltage. A first end of the switching circuit 200 is electrically connected to the third output terminal and the fourth output terminal of the isolation transformer 100, respectively. The second terminal of the switching circuit 200 is grounded. The control terminal of the switching circuit 200 is configured to receive a trigger control signal.

In one embodiment, the first input terminal and the second input terminal of the isolation transformer 100 are both used for electrically connecting to the power source 101, which means: the power supply voltage boosted by the power supply 101 is input to the isolation transformer 100 through the first input terminal and the second input terminal of the isolation transformer 100, respectively. Specifically, the power supply 101 may input the power supply voltage to the isolation transformer 100 through a first input terminal and a second input terminal of the isolation transformer 100 respectively through wires. In one embodiment, the power source 101 may be a dc power source. For example: the power source 101 may be a battery, a dry cell, or the like.

In one embodiment, the first voltage output by the first output terminal of the isolation transformer 100 and the second voltage output by the second output terminal of the isolation transformer 100 may be used for a supply voltage of a load. In one embodiment, the first voltage and the second voltage may be the same or different. In one embodiment, the two output terminals of the isolation transformer 100 can provide two output voltages (i.e., the first voltage and the second voltage), which can be adapted to two loads, and the applicability is strong.

The power supply 101 (connected to the primary side of the isolation transformer 100) and the power supply at the RS485 control end (connected to the secondary side of the isolation transformer 100) are isolated by the isolation transformer 100, and when the power supply at the RS485 control end is abnormal, such as short circuit or unstable voltage, the power supply 101 is not affected. Meanwhile, the isolation transformer 100 can also isolate the interference signal of the RS485 control end to avoid entering the power supply 101; thereby ensuring the stability of the power supply 101 and making the whole system more reliable.

It is understood that the specific circuit structure of the switch circuit 200 is not limited as long as it has a function of turning on based on the trigger control signal. The specific circuit structure of the switching circuit 200 can be selected according to actual requirements. In one embodiment, the switching circuit 200 may be an IGBT (Insulated Gate Bipolar Transistor). In one embodiment, the switching circuit 200 may also be other switching tubes, such as thyristors.

In one embodiment, the trigger control signal (488KHZ) can be provided by a single chip microcomputer. In one embodiment, the trigger control signal may also be provided by an MCU (micro control unit).

In this embodiment, the isolation transformer 100 isolates the power supply 101 (connected to the primary side of the isolation transformer) from the RS485 control terminal power supply (connected to the secondary side of the isolation transformer), and the isolation transformer is matched with the switching circuit 200 to convert the primary dc voltage into the ac voltage, so that the energy is coupled to the secondary side through the isolation transformer 100, and thus when the RS485 control terminal power supply is abnormal, the main power supply is not affected, and the stability of the system is improved.

Referring to fig. 2, in one embodiment, the switching circuit 200 includes: and a MOS transistor 210. The drains of the MOS transistors 210 are electrically connected to the third output terminal and the fourth output terminal of the isolation transformer 100, respectively. The source of the MOS transistor 210 is grounded. The gate of the MOS transistor 210 is configured to receive the trigger control signal. In one embodiment, the gate of the MOS transistor 210 can be triggered by the trigger control signal, so that the MOS transistor 210 is turned on, that is, the drain and the source of the MOS transistor 210 are turned on, and further, the voltage at the input side of the isolation transformer 100 can be coupled to the secondary side for the RS485 control terminal, thereby improving the safety of use. In one embodiment, the MOS transistor 210 may be an N-channel enhancement MOS transistor.

In one embodiment, the isolated power supply 10 further comprises: a first capacitor 220. The trigger control signal is input to the gate of the MOS transistor 210 through the first capacitor 220. In one embodiment, the trigger control signal may be coupled to the gate of the MOS transistor 210 through the first capacitor 220, so as to control the MOS transistor 210 to be turned on. That is, the trigger control signal can be input to the gate of the MOS transistor 210 in a capacitive coupling manner, so that signal consumption is reduced, and multiple groups of MOS transistors can be driven.

In one embodiment, the isolated power supply 10 further comprises: a protection circuit 300. A first terminal of the protection circuit 300 is electrically connected to a control terminal of the switching circuit 200. The second terminal of the protection circuit 300 is grounded. In one embodiment, the specific circuit structure of the protection circuit 300 is not limited as long as it has a function of protecting the switching circuit 200 from being damaged. In one embodiment, the protection circuit 300 may be a reverse diode.

In one embodiment, the protection circuit 300 may also include: a first diode 310 and a resistor 320. The cathode of the first diode 310 is electrically connected to the control terminal of the switching circuit 200. The anode of the first diode 310 is grounded. A first terminal of the resistor 320 is electrically connected to a cathode of the first diode 310 and a control terminal of the switch circuit 200, respectively. A second terminal of the resistor 320 is connected to ground. The control end of the switch circuit 200 is reversely protected by the first diode 310, so that the potential of the control end of the switch circuit 200 is not lower than GND (about 0.6V), and the switch circuit 200 (i.e., the MOS transistor 210) is not turned off too deeply. In one embodiment, the resistor 320 may enable the switch circuit 200 to default to the off state when no control signal is applied, and also function to drain the charge at the control end.

In one embodiment, the isolated power supply 10 further comprises: the first rectifying and filtering circuit 400. The input end of the first rectifying and filtering circuit 400 is electrically connected to the first output end of the isolation transformer 100. The output end of the first rectifying and filtering circuit 400 is used for outputting the first voltage.

It is to be understood that the specific circuit structure of the first rectifying and filtering circuit 400 is not limited as long as it has the function of rectifying and filtering. The specific circuit structure of the first rectifying and filtering circuit 400 can be selected according to actual requirements. In one embodiment, the first rectifying and filtering circuit 400 may be composed of a rectifier and a filter. In one embodiment, the first rectifying and filtering circuit 400 may also be constructed by a rectifying bridge and a filtering capacitor. The first rectifying and filtering circuit 400 rectifies and filters the first voltage output by the first output terminal of the isolation transformer 100, so that signal interference can be reduced, transmission of partial harmonic waves can be prevented, the output voltage (i.e., the first voltage) of the isolation power supply 10 can be stabilized, and the anti-interference capability of the isolation power supply 10 can be improved.

In one embodiment, the first rectifying and filtering circuit 400 includes: a second diode 410 and a second capacitor 420. The anode of the second diode 410 is electrically connected to the first output terminal of the isolation transformer 100. The cathode of the second diode 410 is used for outputting the first voltage. A first terminal of the second capacitor 420 is electrically connected to a cathode of the second diode 410. A second terminal of the second capacitor 420 is grounded. The first voltage output by the first output terminal of the isolation transformer 100 is rectified by the second diode 410, and the rectified first voltage is filtered again by the second capacitor 420, so that interference is reduced, and the anti-interference capability is improved.

In one embodiment, the isolated power supply 10 further comprises: and a second rectifying and smoothing circuit 500. The input end of the second rectifying and filtering circuit 500 is electrically connected to the second output end of the isolation transformer 100. The output end of the second rectifying and filtering circuit 500 is used for outputting the second voltage.

It is to be understood that the specific circuit structure of the second rectifying and filtering circuit 500 is not limited as long as it has the function of rectifying and filtering. The specific circuit structure of the second rectifying and filtering circuit 500 can be selected according to actual requirements. In one embodiment, the second rectifying and filtering circuit 500 may be composed of a rectifier and a filter. In one embodiment, the second rectifying and filtering circuit 500 may also be constructed by a rectifying bridge and a filtering capacitor. The second rectifying and filtering circuit 500 rectifies and filters the second voltage output by the second output terminal of the isolation transformer 100, so that signal interference can be reduced, transmission of partial harmonic waves can be prevented, the output voltage (i.e., the second voltage) of the isolation power supply 10 can be stabilized, and the anti-interference capability of the isolation power supply 10 can be improved.

In one embodiment, the second rectifying and filtering circuit 500 includes: a third diode 510 and a third capacitor 520. The anode of the third diode 510 is electrically connected to the second output terminal of the isolation transformer 100. The cathode of the third diode 510 is used for outputting the second voltage. A first terminal of the third capacitor 520 is electrically connected to a cathode of the third diode 510. A second terminal of the third capacitor 520 is grounded. The second voltage output by the second output terminal of the isolation transformer 100 is rectified by the third diode 510, and the rectified second voltage is filtered again by the third capacitor 520, so that interference is reduced, and the anti-interference capability is improved.

In one embodiment, the isolated power supply 10 further comprises: a fourth capacitor 600. A first end of the fourth capacitor 600 is electrically connected to the power supply 101, and a first input end and a second input end of the isolation transformer 100, respectively. A second terminal of the fourth capacitor 600 is grounded. The first input end and the second input end of the isolation transformer 100 are protected by the fourth capacitor 600, so that the isolation transformer 100 is prevented from being damaged due to overlarge power supply voltage provided by the power supply 101, and the safety is improved.

To sum up, this application passes through isolating transformer 100 keeps apart power 101 (insert isolating transformer is elementary) and RS485 control end power (insert isolating transformer secondary), and with switching circuit 200 cooperates, changes elementary DC voltage into alternating voltage, makes the energy pass through isolating transformer 100 couples to secondary to when RS485 control end power appears unusually, can not cause the influence to the main power supply, improve the stability of system.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An isolated power supply, comprising:

the first input end and the second input end of the isolation transformer (100) are both used for being electrically connected with a power supply (101), the first output end of the isolation transformer (100) outputs a first voltage, and the second output end of the isolation transformer (100) outputs a second voltage; and

the first end of the switch circuit (200) is electrically connected with the third output end and the fourth output end of the isolation transformer (100) respectively, the second end of the switch circuit (200) is grounded, and the control end of the switch circuit (200) is used for receiving a trigger control signal.

2. The isolated power supply of claim 1, wherein the switching circuit (200) comprises:

the drain electrode of the MOS tube (210) is respectively electrically connected with the third output end and the fourth output end of the isolation transformer (100), the source electrode of the MOS tube (210) is grounded, and the grid electrode of the MOS tube (210) is used for receiving the trigger control signal.

3. The isolated power supply of claim 2, further comprising:

the trigger control signal is input to the gate of the MOS transistor (210) through the first capacitor (220).

4. The isolated power supply of claim 1, further comprising:

and a first end of the protection circuit (300) is electrically connected with the control end of the switch circuit (200), and a second end of the protection circuit (300) is grounded.

5. The isolated power supply of claim 4, wherein the protection circuit (300) comprises:

a first diode (310), a cathode of the first diode (310) being electrically connected to a control end of the switching circuit (200), an anode of the first diode (310) being grounded; and

and a resistor (320), wherein a first end of the resistor (320) is electrically connected with a cathode of the first diode (310) and a control end of the switch circuit (200), respectively, and a second end of the resistor (320) is grounded.

6. The isolated power supply of claim 1, further comprising:

the input end of the first rectifying and filtering circuit (400) is electrically connected with the first output end of the isolation transformer (100), and the output end of the first rectifying and filtering circuit (400) is used for outputting the first voltage.

7. The isolated power supply of claim 6 wherein said first rectifying and filtering circuit (400) comprises:

a second diode (410), an anode of the second diode (410) being electrically connected to the first output terminal of the isolation transformer (100), a cathode of the second diode (410) being used for outputting the first voltage; and

a second capacitor (420), a first terminal of the second capacitor (420) being electrically connected to the cathode of the second diode (410), a second terminal of the second capacitor (420) being grounded.

8. The isolated power supply of claim 1, further comprising:

and the input end of the second rectifying and filtering circuit (500) is electrically connected with the second output end of the isolation transformer (100), and the output end of the second rectifying and filtering circuit (500) is used for outputting the second voltage.

9. The isolated power supply of claim 8 wherein said second rectifying and filtering circuit (500) comprises:

a third diode (510), an anode of the third diode (510) being electrically connected to the second output terminal of the isolation transformer (100), a cathode of the third diode (510) being used for outputting the second voltage; and

a third capacitor (520), a first terminal of the third capacitor (520) being electrically connected to the cathode of the third diode (510), and a second terminal of the third capacitor (520) being grounded.

10. The isolated power supply of claim 1, further comprising:

and a first end of the fourth capacitor (600) is electrically connected with the power supply (101), the first input end and the second input end of the isolation transformer (100) respectively, and a second end of the fourth capacitor (600) is grounded.