CN217766770U

CN217766770U - Current-adjustable switch power supply EMC test load device

Info

Publication number: CN217766770U
Application number: CN202221610428.4U
Authority: CN
Inventors: 马涛
Original assignee: Shenzhen Topow Electronics Co ltd
Current assignee: Shenzhen Topow Electronics Co ltd
Priority date: 2022-06-21
Filing date: 2022-06-21
Publication date: 2022-11-08
Anticipated expiration: 2032-06-21

Abstract

The utility model discloses a switching power supply EMC test load device of adjustable current, this test load device includes power output end, power triode, TI431 control chip, load resistance, current regulation point location ware, this test load device includes adjustable voltage stabilizing circuit, adjustable voltage stabilizing circuit's circuit core comprises U1, Q1, R2, VR1, R3; the device of the utility model adopts the three-terminal voltage stabilizer TL431 as a control core, and is provided with fewer devices at the periphery, so that the load current can be continuously adjusted, thereby meeting the test requirements under various load conditions, and the device has the advantages of simple circuit, low cost, convenient adjustment and the like, is mainly applied to the conduction/radiation test of the power supply monomer with low-voltage direct current output of 3.3-35V, and can meet the test requirements of most power supply specifications in the market; a complicated load resistor configuration process is not needed, so that time is saved; the specification and model of the resistor are reduced, only one resistor specification is needed to be used for one output specification, and the test cost is reduced.

Description

Current-adjustable switch power supply EMC test load device

Technical Field

The utility model relates to a EMC tests load device technical field, specifically is an adjustable current's switching power supply EMC tests load device.

Background

At present, the conduction/radiation of the switching power supply unit needs to be tested: 1. some customers require the power supply unit to simulate the load condition of the actual work of the complete machine, the conduction/radiation of the power supply under the load conditions of 10%, 25%, 50%, 75% and 100% is required to be tested, and the load resistor with the corresponding resistance value needs to be configured according to the rated output voltage of the power supply. One output specification needs to be configured with at least 5 specifications of resistors, then N output specifications need to be configured with 5 × N resistors, and some special resistance values need to be customized or obtained in a resistor series/parallel connection mode; 2. the mode has low working efficiency, the resistor configuration process is complex, the used resistor has too many specifications and models, and the test cost is increased, so that the switching power supply EMC test load device with the adjustable current needs to be provided.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a switching power supply EMC test load device of adjustable current utilizes TL431 three terminal regulator as the core, and the collocation peripheral circuit realizes the load of adjustable current, mainly is applied to the power monomer conduction/radiation test of low pressure direct current 3.3-35V output, can satisfy the test demand of most power specifications on the market; a complex load resistor configuration process is not needed, so that the time is saved, and the working efficiency is improved; the specification and model of the resistor are reduced, only one resistor specification is needed to be used for one output specification, and the test cost is reduced, so that the problems in the background technology are solved.

In order to achieve the above purpose, the utility model provides a following technical scheme:

a switching power supply EMC test load device capable of adjusting current comprises a power output end, a power triode, a TI431 control chip, a load resistor, a current adjusting point positioner and an LED digital display module;

the power triode electric property is connected in series to the load resistance, the power triode passes through load resistance electric connection in current regulation point location ware, load resistance passes through current regulation point location ware electric connection in TI431 control chip, current regulation point location ware passes through TI431 control chip electric connection in the power triode, power output end electric connection in power triode and LED digital display module, the one end electric connection that the power triode was kept away from to the load resistance is in LED digital display module.

Preferably, the test load device includes an adjustable voltage regulator circuit, a circuit core of the adjustable voltage regulator circuit is composed of U1, Q1, R2, VR1, and R3, an output voltage = [ (R2 + VR 2)/R3 +1] × 2.5, and the output voltage is a voltage across EC2 and the load resistor RP.

Preferably, the current through RP is I = U/R according to ohm's law, and the current through RP = the current through Q1 = the output load current of the power supply, again according to the principle of equality of currents in the series circuit.

Preferably, when the load current needs to be changed, only VR1 needs to be adjusted, and the voltage across RP is changed to realize the adjustment of the load current.

Preferably, the LED digital display module is used for directly and clearly displaying real-time voltage and real-time load current input by the device, and the LED digital display module is provided with a voltage display area and a current display area.

Preferably, when the input voltages of the test load devices are different, RP with different resistance values need to be matched so as to obtain the required test load current.

Compared with the prior art, the beneficial effects of the utility model are that:

the device adopts the three-terminal voltage stabilizer TL431 as a control core, is matched with fewer devices at the periphery, realizes the continuous adjustment of load current so as to meet the test requirements under various load conditions, has the advantages of simple circuit, low cost, convenient adjustment and the like, is mainly applied to the conduction/radiation test of a power supply monomer with low-voltage direct current output of 3.3-35V, and can meet the test requirements of most power supply specifications in the market; a complex load resistor configuration process is not needed, so that the time is saved, and the working efficiency is improved; the specification and the model of the resistor are reduced, only one resistor specification is needed to be used for one output specification, and the test cost is reduced.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

Fig. 1 is a schematic structural view of the present invention;

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

Detailed Description

The same reference numbers in different drawings identify the same or similar elements; it should be further understood that terms such as "first," "second," "third," "upper," "lower," "front," "rear," "inner," "outer," "end," "portion," "section," "width," "thickness," "zone," and the like are used herein only for convenience in reference to the figures and to merely aid in describing the invention, and are not intended to limit the invention.

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. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides an embodiment:

a switching power supply EMC test load device capable of adjusting current comprises a power output end, a power triode, a TI431 control chip, a load resistor, a current adjusting point location device and an LED digital display module;

The test load device comprises an adjustable voltage stabilizing circuit, wherein a circuit core of the adjustable voltage stabilizing circuit consists of U1, Q1, R2, VR1 and R3, the output voltage = [ (R2 + VR 2)/R3 +1 ]. Multidot.25, and the output voltage is the voltage at two ends of EC2 and a load resistor RP; according to ohm's law, the current through RP is I = U/R, and further according to the principle of current equality in a series circuit, the current through RP = the current through Q1 = the output load current of the power supply; when the load current needs to be changed, the load current can be adjusted by only adjusting VR1 and changing the voltage at the two ends of RP.

The LED digital display module is used for directly and clearly displaying real-time voltage and real-time load current input by the device and is provided with a voltage display area and a current display area; when the input voltages of the test load devices are different, the RPs with different resistances need to be matched so as to obtain the required test load current.

The working principle is as follows:

the device is connected with the output end of a power supply to be tested through a power supply switch, when the switch is switched on, the power supply enters a loaded state, VR1 is regulated, and a required load current can be obtained by observing an ammeter.

2, the circuit core is an adjustable voltage stabilizing circuit composed of U1, Q1, R2, VR1, R3, etc., the output voltage = [ (R2 + VR 2)/R3 +1] × 2.5, and the holding voltage is stabilized within an error range of about 2.5%, as can be seen from the schematic diagram, this voltage is the voltage across EC2 and the load resistor RP. When this voltage is applied across RP, then the current through RP is I = U/R according to ohm's law, and again, according to the principle of current equality in a series circuit, the current through RP = the current through Q1 = the output load current of the power supply;

3, when the load current needs to be changed, only VR1 needs to be adjusted, and the voltage at the two ends of RP is changed, so that the adjustment of the load current is realized.

4, this device still has LED digital display module, directly clearly shows the real-time electric pressure display and real-time load current of device input.

When the input voltages are different, RP with different resistances need to be matched so as to obtain the required test load current.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A switching power supply EMC test load device capable of adjusting current is characterized by comprising a power output end, a power triode, a TI431 control chip, a load resistor, a current adjusting point location device and an LED digital display module;

2. A current regulated switching power supply EMC test load device according to claim 1, characterized in that: the load testing device comprises an adjustable voltage stabilizing circuit, wherein a circuit core of the adjustable voltage stabilizing circuit consists of U1, Q1, R2, VR1 and R3, the output voltage = [ (R2 + VR 2)/R3 +1 ]. Multidot.25, and the output voltage is the voltage at two ends of EC2 and a load resistor RP.

3. A current regulated switching power supply EMC test load apparatus as claimed in claim 2, wherein: according to ohm's law, the current through RP is I = U/R, and again according to the principle of current equality in a series circuit, the current through RP = the current through Q1 = the output load current of the power supply.

4. A current regulated switching power supply EMC test load arrangement as claimed in claim 3, characterized in that: when the load current needs to be changed, the load current can be adjusted by only adjusting VR1 and changing the voltage at the two ends of RP.

5. A current adjustable switching power supply EMC test load apparatus as claimed in claim 1, wherein: the LED digital display module is used for directly and clearly displaying real-time voltage and real-time load current input by the device and is provided with a voltage display area and a current display area.

6. A current regulated switching power supply EMC test load device according to claim 1, characterized in that: when the input voltages of the test load devices are different, the RPs with different resistances need to be matched so as to obtain the required test load current.