CN211788406U - Wide-range linear adjustable resistance load device - Google Patents

Abstract

The utility model relates to an electrical equipment and electrical engineering field, concretely relates to linear adjustable resistance load device of wide range. The device comprises a main circuit, wherein the main circuit comprises an M omega-gear relay resistance unit, a K omega-gear relay resistance unit, an omega-gear relay resistance unit and an M omega-gear relay resistance unit; the M omega-level relay resistance unit, the K omega-level relay resistance unit, the omega-level relay resistance unit and the M omega-level relay resistance unit are connected in parallel and are connected in series with an MOSFET circuit switching relay unit, a fuse and a wiring pile. The precision of the resistance device is improved; the automation level is improved, and the resistance value can be quickly adjusted and displayed; the cost is reduced; the wide-range linear adjustability of the resistance value of the resistor can be realized; the resistance value can be accurately adjusted and read; the resistance value of the resistor does not need to be changed due to temperature when the resistor is used; increasing the power level of the device; providing warning of excessive power and overload protection; the automation degree is high, and the operation is rapid and convenient; no mechanical abrasion and prolonged service life.

Description

Wide-range linear adjustable resistance load device

Technical Field

The utility model relates to an electrical equipment and electrical engineering field, concretely relates to linear adjustable resistance load device of wide range.

Background

At present, the continuous adjustable resistance load devices on the market are mainly a scribing rheostat, a disc adjustable resistor, a program-controlled electronic load and the like. The adjustable resistances of the scribing rheostat and the disc are adjusted manually or by electronic and hydraulic assistance, and the resistance is adjusted in a mechanical contact mode. Although the adjustable load resistance is continuously adjustable, the adjustable range of the load resistance is also wider, but the following problems exist:

1) the precision is limited by inconsistent precision of the resistor, resistance value change of the resistor caused by temperature change and position precision of a contact point in the adjusting process of the mechanical adjusting device;

2) mechanical contact is needed when the resistance value is adjusted, mechanical abrasion is caused, and the service life of the load is shortened;

3) the read resistance value is adjusted through a dial, the adjustment of the resistance value and the reading speed are too slow and are easy to read by mistake, for the discontinuous variable resistance load device on the market, the resistance value can only be adjusted between a plurality of gears by a method of manually exchanging binding posts, and the adjustment range is narrow;

4) since the scribing resistor or the disc adjustable resistor is used as a component unit of the variable resistance load, the power is difficult to be made and the cost is high.

Although the electronic loads on the market are of a wide variety, the current technology is mature, and the continuity including the precision is also quite superior, the disadvantages are obvious, such as the following problems:

1) when a high-power load is made, the high-power load is limited by the technology of the MOSFET, and more paths can only be connected in parallel continuously, so that the paths cannot be equalized well, and the paths cannot be increased by corresponding multiples;

2) the resistance range of the analog resistor is also narrow;

3) the cost of the high-power MOSFET is increased along with the selection of the high-power MOSFET.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior variable resistance load device, the utility model provides a wide-range linear adjustable resistance load device. The method mainly combines a fixed value resistor array and a program control electronic load to achieve the purposes of mainly adjusting the fixed value resistor array and secondarily adjusting and compensating the program control electronic load.

The utility model provides a technical scheme that its technical problem adopted is: a wide-range linear adjustable resistance load device comprises a main circuit, wherein the main circuit comprises an M omega-gear relay resistance unit, a K omega-gear relay resistance unit, an omega-gear relay resistance unit and an M omega-gear relay resistance unit; the M omega-level relay resistance unit, the K omega-level relay resistance unit, the omega-level relay resistance unit and the M omega-level relay resistance unit are connected in parallel and are connected in series with an MOSFET circuit switching relay unit, a fuse and a wiring pile;

the system comprises a keyboard, a nixie tube display, a singlechip minimum system, a relay drive circuit, a MOSFET drive circuit and a sampling feedback circuit, wherein the adjusting display control circuit comprises the keyboard, the nixie tube display, the singlechip minimum system, the relay drive circuit, the MOSFET drive circuit and the sampling feedback circuit;

further, the intelligent control device also comprises a control panel, wherein the control panel comprises a switch button, a key, a display part and a wiring pile.

1) The principle of realizing the wide-range adjustment of the resistance of the device is as follows:

dividing the whole resistance threshold into stages (M Ω, K Ω, M Ω) each including 15 resistors, for example, designing the Ω stage to have resistances of 1 Ω × 1+2 Ω × 2+5 Ω × 1 in units of one, 10 Ω × 1+20 Ω × 2+50 Ω × 1 in tens of units of one, and 100 Ω × 1+200 Ω × 2+500 Ω × 1 in corresponding hundreds of units of one; the rest gears are analogized in the same way. Each resistor is respectively connected with a relay in parallel to form a relay resistor unit, and then the relay resistor units are connected in series one by one (as shown in fig. 1), so that when the relay is switched on, the corresponding resistor is short-circuited, and when the relay is switched on, the corresponding resistor is switched in, so that different resistors can be switched in the total resistor through different combinations of the switching-on states of the relay Si (i is 0, 1, 2, … and n-1), and the wide-range adjustment of the resistance value of the load resistor is realized. Because the error exists between the access total resistance and the set resistance value, the conduction angle of the MOSFET is controlled by the feedback loop to simulate a variable compensation resistance, and the real-time compensation correction is carried out on the total resistance, so that the precision is improved.

2) The method for conveniently adjusting the reading resistance value comprises the following steps:

as can be seen from the above resistance value adjusting principle, actually, the resistance value of the load resistor and the on-off state of the relay Si (i is 0, 1, 2, …, and n-1) are in a one-to-one correspondence relationship, so that the load resistance value can be adjusted by controlling the on-off state of the relay. The on-off of the relay can be controlled by the single chip microcomputer, so that the digitization of resistance value adjustment is realized. The digital tube digital switch comprises a digital tube, a singlechip, a keyboard, a relay, a drive switch, a switch and a switch. The key adjustment and digital display bring convenience to the accurate adjustment and reading of the resistance value of the load resistor;

3) the method for warning of excessive power and protecting in overload comprises the following steps:

a fuse is connected in series in the series resistor;

4) method for reducing costs:

low-cost resistors such as a corrugated wire-wound resistor or a glazed wire-wound resistor are used for replacing high-cost resistors such as a slide rheostat and a disc adjustable resistor. On the one hand the cost of the device can be reduced and on the other hand the power class of the device can be increased.

The utility model has the advantages that: 1) the precision of the resistance device is improved; 2) the automation level is improved, and the resistance value can be quickly adjusted and displayed; 3) the cost is greatly reduced; 4) the wide-range linear adjustability of the resistance value of the resistor can be realized; 5) the resistance value can be accurately adjusted and read; 6) the resistance value of the resistor does not need to be changed due to temperature when the resistor is used; 7) increasing the power level of the device; 8) providing warning of excessive power and overload protection; 7) the automation degree is high, and the operation is rapid and convenient; 8) no mechanical abrasion and prolonged service life.

Drawings

FIG. 1 is a system configuration diagram of the present invention;

fig. 2 is a schematic view of the control panel of the present invention.

Detailed Description

The wide range linearly adjustable resistive load apparatus shown in fig. 1-2, including the following embodiments, is described in further detail in conjunction with the accompanying drawings: this embodiment is implemented on the premise of the technical solution of the present invention, and an implementation manner and an operation process are given, but the scope of the present invention is not limited to the following embodiments.

In this embodiment, the resistance value of the digital wide-range adjustable resistor load may be any integer between 0 and 1G Ω, and the specific implementation manner is as follows: a wide-range linear adjustable resistance load device comprises a main circuit, wherein the main circuit comprises an M omega-gear relay resistance unit, a K omega-gear relay resistance unit, an omega-gear relay resistance unit and an M omega-gear relay resistance unit; the M omega-level relay resistance unit, the K omega-level relay resistance unit, the omega-level relay resistance unit and the M omega-level relay resistance unit are connected in parallel and are connected in series with an MOSFET circuit switching relay unit, a fuse and a wiring pile;

in this embodiment, the system further comprises an adjustment display control circuit, wherein the adjustment display control circuit comprises a keyboard, a nixie tube display, a single-chip microcomputer minimum system, a relay drive circuit, a MOSFET drive circuit and a sampling feedback circuit, the single-chip microcomputer minimum system is connected with a latch set, an input port of the latch set is connected with the keyboard, and an output port of the latch set is respectively connected with the nixie tube display, the relay drive circuit, the MOSFET drive circuit and the sampling feedback circuit;

in this embodiment, as shown in fig. 2, the control panel mainly comprises a switch button, a digital display, a key and a wiring stub, wherein the switch button 0 controls whether the whole system is put into operation.

The working principle is as follows:

a main circuit part: (see FIG. 1)

Inputting the resistance value required by the minimum system of the single chip microcomputer through a keyboard, operating a control algorithm by the minimum system of the single chip microcomputer, outputting a signal to a relay drive circuit one way, outputting a signal to a drive circuit of a MOSFET (metal oxide semiconductor field effect transistor) to control the conduction angle of the MOSFET one way, and outputting a signal to a relay which controls whether the MOSFET circuit is connected into a main circuit or not;

2) judging the current actual resistance value through the voltage division of the sampling resistor, comparing the current actual resistance value with a set value, and if the actual total resistance value is smaller than the set resistance value, controlling the relay to switch the MOSFET circuit into the main circuit and controlling the conduction angle opening of the MOSFET by the singlechip until the actual total resistance value is equal to the set resistance value;

3) judging the current actual resistance value through the voltage division of the sampling resistor, comparing the current actual resistance value with a set value, if the actual total resistance value is larger than the set resistance value, the single chip microcomputer controls the relay resistor unit to switch the lowest stage resistor out of the main circuit and then judge the total resistance value, if the actual total resistance value is smaller than the set value, the single chip microcomputer controls the relay to switch the MOSFET circuit into the main circuit and control the conduction angle opening of the MOSFET circuit until the actual total resistance value is equal to the set resistance value;

control the display circuit section: (see FIG. 1)

1) The key is connected to the minimum system input port of the STM32F103ZET6, the output port of the single chip microcomputer STM32F103ZET6 is connected with a latch SN74HC573NSR, and then the relay is further driven through a Darlington tube array ULN2003ADR, and the relay can switch the required resistance into a circuit;

2) the feedback loop sends the voltage of the sampling resistor to the singlechip for processing;

3) the auxiliary power supply is connected with STM32F103ZET6, SN74HC573NSR, ULN2003ADR and a drive circuit of a relay MOSFET, MC78M12CDTRKG and NJM79M12DL1A provide +12V and-12V power supplies required by the chips, the drive circuit of the MOSFET is connected to provide the +12V and-12V power supplies required by the chips, the +12V provides a power supply of a Darlington tube array and a relay, LM2734XMKX (SFDB) provides a +5V power supply for a latch, and LM1117 provides power for a single chip microcomputer;

4) the minimum system of the single chip microcomputer comprises a reset circuit and a crystal oscillator circuit which are necessary for the single chip microcomputer and are connected to the single chip microcomputer STM32F103ZET 6.

5) The display part controls the display of the 8-bit nixie tube by driving the SN74HC573NSR by the singlechip;

the above embodiments are only specific cases of the present invention, and the protection scope of the present invention includes but is not limited to the forms and styles of the above embodiments, and any suitable changes or modifications made thereto by the ordinary skill in the art in accordance with the claims of the present invention shall fall within the protection scope of the present invention.

Claims (3)

1. A wide range linearly adjustable resistive load device, characterized by: the device comprises a main circuit, wherein the main circuit comprises an M omega-gear relay resistance unit, a K omega-gear relay resistance unit, an omega-gear relay resistance unit and an M omega-gear relay resistance unit; the M omega-level relay resistance unit, the K omega-level relay resistance unit, the omega-level relay resistance unit and the M omega-level relay resistance unit are connected in parallel and are connected in series with an MOSFET circuit switching relay unit, a fuse and a wiring pile.

2. The wide range linearly tunable resistive load arrangement of claim 1, wherein: still show control circuit including the adjustment, keyboard, charactron that adjustment display control circuit includes shows, singlechip minimum system, relay drive circuit, MOSFET drive circuit and sampling feedback circuit, the minimum system of singlechip is connected with latch group, the input port connection keyboard of latch group, charactron demonstration, relay drive circuit, MOSFET drive circuit and sampling feedback circuit are connected respectively to the delivery outlet of latch group.

3. The wide range linearly tunable resistive load arrangement of claim 2, wherein: the control panel comprises a switch button, a key, a display component and a wiring pile.

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