U.S. patent application number 16/534019 was filed with the patent office on 2019-11-28 for method and apparatus for providing auxiliary and welding type power with thermal protection.
This patent application is currently assigned to Illinois Tool Works Inc.. The applicant listed for this patent is Illinois Tool Works Inc.. Invention is credited to Quinn W. Schartner, Brian A. Schwartz.
Application Number | 20190358728 16/534019 |
Document ID | / |
Family ID | 54330894 |
Filed Date | 2019-11-28 |
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United States Patent
Application |
20190358728 |
Kind Code |
A1 |
Schwartz; Brian A. ; et
al. |
November 28, 2019 |
Method and Apparatus for Providing Auxiliary and Welding Type Power
With Thermal Protection
Abstract
A method and apparatus for providing welding-type power supply
includes a power circuit and a controller. The power circuit
receives input power and provides welding type power and auxiliary
power. It is controlled on a control input. The power circuit also
includes an auxiliary power transformer. A temperature responsive
component is mounted in the auxiliary power transformer and
provides a temperature signal indicative of the temperature in the
auxiliary power transformer. The controller controls a cooling fan
for the aux power transformer and/or turns off the aux power output
in response to the sensed temperature.
Inventors: |
Schwartz; Brian A.;
(Appleton, WI) ; Schartner; Quinn W.; (Kaukauna,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Illinois Tool Works Inc. |
Glenview |
IL |
US |
|
|
Assignee: |
Illinois Tool Works Inc.
Glenview
IL
|
Family ID: |
54330894 |
Appl. No.: |
16/534019 |
Filed: |
August 7, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14535773 |
Nov 7, 2014 |
10406623 |
|
|
16534019 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23K 9/1043 20130101;
H05K 7/20136 20130101; H01F 27/402 20130101; B23K 9/1006 20130101;
H01F 38/085 20130101; H01F 2027/406 20130101 |
International
Class: |
B23K 9/10 20060101
B23K009/10; H05K 7/20 20060101 H05K007/20; H01F 27/40 20060101
H01F027/40; H01F 38/08 20060101 H01F038/08 |
Claims
1-8. (canceled)
9. A method of protecting a welding-type power supply comprising:
receiving input power and converting it to welding power, including
transforming power with an auxiliary transformer into auxiliary
power; sensing the temperature of the auxiliary transformer;
controlling the transforming in response to the sensing.
10. The method of claim 9, further comprising turning on and off at
least one fan mounted to cool at least the auxiliary transformer,
wherein turning on and off is done in response to the sensing.
11. The method of claim 10, wherein turning on and off includes
turning the at least one fan off when the auxiliary transformer is
at a fan off temperature, and turning the at least one fan on at a
fan on temperature, wherein the fan off temperature is less than
the fan on temperature.
12. The method of claim 11, wherein controlling the converting and
transforming includes disabling a utility output in response to the
temperature of the auxiliary transformer exceeding a threshold.
13. The method of claim 12, wherein controlling the converting and
transforming includes disabling an output in response to the
temperature of the auxiliary transformer exceeding a threshold.
14. The method of claim 13, wherein disabling an output includes
opening a relay in series with a utility power output.
15-19. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present disclosure relates generally to welding type
power supplies having electrical transformers. More specifically,
it relates to transformers for use in creating auxiliary power.
BACKGROUND OF THE INVENTION
[0002] Transformers are commonly used in welding type power
supplies. Welding type power supply, as used herein, is a power
supply that provides a welding type output. Welding type output, as
used herein, is an output suitable for welding, plasma cutting, or
induction heating. Welding type power supplies have a wide variety
of topologies. For example, they can include a preregulator to
provide a bus, and have an output converter that converts the bus
into a desired current and voltage. Examples of preregulators
include boosts, bucks, rectifiers, etc. Examples of output
converters, include inverters, boosts, bucks, choppers, etc.
Welding type power supplies can have additional, intermediate
stages, and can receive utility power as input power, or include a
generator.
[0003] Many welding type power supplies include an auxiliary power
output. This is often provided at 120 volts (or other utility
voltages power), and can be derived by transforming input power, or
derived from a bus by a converter (such as inverter). Auxiliary
power derived by inverting the bus is also usually transformed (to
provide the desired 120V ac). Thus, when auxiliary power is
provided it is common to have an auxiliary power transformer.
Auxiliary power, as used herein, includes power provided other than
on the main power output of a welding type power supply.
[0004] Many welding type power supplies include a weld power
transformer that handles the primary welding type output of the
power supply. Weld power transformers can become overheated and are
typically cooled by a fan (or fans) . Some prior art welding type
power supplies turn the fan(s) on and off as needed, in response to
the temperature of the welding transformer.
[0005] The auxiliary power transformer is often cooled by the same
fan as the weld transformer. However, the prior art does not use
the temperature of the auxiliary transformer to determine when the
fan should be turned on and off Thus, cooling is only provided when
the weld transformer becomes hot. Accordingly, a welding-type power
supply that has an auxiliary power transformer that is cooled by a
fan controlled in response to the auxiliary power transformer
temperature is desired.
SUMMARY OF THE PRESENT INVENTION
[0006] According to a first aspect of the disclosure a welding-type
power supply includes a power circuit and a controller. The power
circuit receives input power and provides welding type power and
auxiliary power, and is controlled on a control input. The power
circuit also includes an auxiliary power transformer. A temperature
responsive component is mounted in the auxiliary power transformer,
and the component provides a temperature signal indicative of the
temperature in the auxiliary power transformer. The controller has
a control output connected to the control input, and has a
temperature control input connected to receive the temperature
signal. A thermal protection module receives the temperature
control input, and the control output is responsive to the thermal
protection module.
[0007] According to a second aspect of the disclosure a method of
protecting a welding-type power supply includes receiving input
power and converting it to welding power, and controlling the
converting and transforming. The converting includes transforming
power with an auxiliary transformer into auxiliary power. The
temperature of the auxiliary transformer is sensed and the
transforming is controlled in response to the sensing.
[0008] The power circuit includes at least one fan that cools at
least the auxiliary power transformer in one alternative. The fan
is turned on and off by a fan on/off module that is part of the
thermal protection module.
[0009] The fan on/off module includes a fan off set point that
corresponds to a fan off temperature, and a fan on set point that
corresponds to a fan on temperature, and the fan off temperature is
less than the fan on temperature in another alternative.
[0010] The thermal protection module includes an auxiliary power
shut down module in one embodiment.
[0011] The auxiliary power shut down module includes a shut down
set point that corresponds to a shut down temperature that is
greater than the fan on temperature in various embodiments.
[0012] The power circuit includes an auxiliary power output and a
relay responsive to the shut down module is in electrical
communication with the auxiliary power output and the auxiliary
power transformer, and wherein the relay is responsive to the shut
down module in another embodiment.
[0013] The temperature responsive component is a thermistor in one
embodiment.
[0014] The auxiliary power transformer includes a utility power
winding, a control power winding, and a winding separator
therebetween, and the thermistor is mounted to and under the
winding separator in various embodiments.
[0015] Other principal features and advantages of will become
apparent to those skilled in the art upon review of the following
drawings, the detailed description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of a welding type power
supply;
[0017] FIG. 2 is a perspective view of a transformer;
[0018] FIG. 3 is an exploded view of the transformer of FIG. 2;
[0019] FIG. 4 is a perspective view of a secondary assembly of
FIGS. 2 and 3;
[0020] FIG. 5 is an exploded view of the secondary assembly of FIG.
4;
[0021] FIG. 6 is a cross sectional view of the windings of FIG.
4;
[0022] FIG. 7 is a block diagram of the controller of FIG. 1;
[0023] FIG. 8 is a block diagram of the power circuit of FIG. 1;
and
[0024] FIG. 9 is a top view of the interior of the welding type
power supply of FIG. 1.
[0025] Before explaining at least one embodiment in detail it is to
be understood that the invention is not limited in its application
to the details of construction and the arrangement of the
components set forth in the following description or illustrated in
the drawings. The invention is capable of other embodiments or of
being practiced or carried out in various ways. Also, it is to be
understood that the phraseology and terminology employed herein is
for the purpose of description and should not be regarded as
limiting. Like reference numerals are used to indicate like
components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] While the present disclosure will be illustrated with
reference to a particular welding type power supply, controller and
transformer, it should be understood at the outset that the
invention can also be implemented with other welding type power
supplies, controllers, transformers, and other components.
[0027] Generally, in accordance with the invention a welding type
power supply 100 (FIG. 1) includes a power circuit 102 and a
control circuit 104. Other items, such as a generator, wire feeder,
welding gun, robot, etc. can be included. Welding type power supply
100 also includes an auxiliary power output module 106, to which
utility power (or other aux power) is provided on output 107. In
the preferred embodiment module 106 provides 120V AC at 60 Hz to
the user.
[0028] Power circuit 102 receives input power, such as power from a
utility or generator, and provides welding type power on a welding
output 103. In the preferred embodiment power circuit 102 includes
a preregulator, a high voltage split bus, and a stacked inverter
output, such as that shown in patent application Ser. No.
13/839235, published as US-2014-0021180-A1, hereby incorporated by
reference. Alternatives provide for using other topologies. Power
circuit 102 includes a transformer 108 which receives power and
provides control and aux power. In the preferred embodiment the
input to the primary of transformer 108 is a power derived from a
bus, such as by an inverter. The primary may alternatively be
connected to utility or generator input power.
[0029] Control power is provided on output 105 to controller 104.
Controller 104 (also called a control circuit) may be located on
one or more boards in one or more places, and can include analog
and digital components, including processors, and can include
software. Control circuit 104 is connected on output 109 to control
power circuit 102, and preferably controls power circuit 102 using
PWM. Control circuit may also receive feedback, such as of the
load, the bus voltages, the type of input, etc. It may also receive
user inputs, such as process selection, set points, etc.
Controller, as used herein, includes digital and analog circuitry,
discrete or integrated circuitry, DSPs, microprocessors, etc., and
software, hardware and firmware, located on one or more boards,
used to control a device such as a power supply.
[0030] Transformer 108 is shown in FIGS. 2 and 3, and includes a
core 201, a primary winding 203, secondary windings 205 and a
mounting plate 207. Primary winding 203 is preferably wound about a
bobbin 211.
[0031] Secondary windings 205 are shown in more detail in FIGS. 4
and 5, as part of secondary assembly 400. Secondary assembly 400
includes control power secondary winding 205, an additional control
power secondary winding 402 (two control power windings are used to
provide two different voltages (24V and 36V in the preferred
embodiment), an aux power secondary winding 404, a bobbin 406, and
a winding separator 408. The outputs of windings 205 and 402 are
provided on lines 105 to control circuit 104. The output of winding
404 is provided on lines 107 to aux module 106.
[0032] Alternatives provide for using one control power winding,
omitting the aux or control power windings, and/or omitting the
winding separator, or changing the order of the windings, such that
one or both control windings are under the separator, and the aux
power winding is above the separator. Also, windings for other
purposes, including a weld power winding, could be included.
[0033] Secondary assembly 400 is assembled with winding 404 wound
about bobbin 406. Winding separator 408 is placed over winding 404.
Winding separator, as used herein, is a part that is formed or
shaped to separate windings, and that provides structure about
which a winding may be wound. It does not include tape. Then,
winding 402 is wound about winding separator 408. Winding 205 is
wound over winding 402 (paper can be used to separate windings 205
and 402). Winding separator 408 provides insulation and increases
the creepage distance between windings 404 and 402. Also, winding
separator 408 provides for air flow past winding 205 to winding
402. Air flow is also provided to winding 404 in some embodiments.
Alternatives provide for not including provisions for air flow.
[0034] A thermistor 420 is mounted over winding 404 and is used by
controller to protect transformer 108 from overheating. Generally,
when controller 104 determines that transformer 108 needs cooling,
based on the temperature dependent resistance of thermistor 420,
controller 108 commands one or more fans to be turned on. When
transformer 104 no longer needs cooling, the fans is turned off If
the temperature is too high, the aux output is disabled, to reduce
the heating of transformer 104. Alternatives provide for using
other temperature responsive components, such as thermocouples,
digital temperature sensors, or other temperature sensitive
devices.
[0035] Turning now to FIG. 6, a cross sectional view of windings
205 and 404 is shown, with thermistor 420 disposed between the
windings. Alternatives include locating the thermistor elsewhere,
such as near the primary, under the aux power winding, between
control windings, on the core, etc.
[0036] FIG. 7 is a block diagram of the portion of controller 104
that relates to protecting the transformer, including a thermal
protection module 702, a fan on/off module 704, and a auxiliary
power shut down module 706. Module, as used herein, includes
software and/or hardware that cooperates to perform one or more
tasks, and can include digital commands, power circuitry,
networking hardware, etc. Thermal protection module, as used herein
is a module that provides thermal protection to at least part of a
welding type power supply. Fan on/off module, as used herein is a
module that causes a fan to be turned on or off. Auxiliary power
shut down module, as used herein is a module that causes the aux
power (or a portion thereof) to be shut down, such that it is not
available to the user.
[0037] Controller 104 receives the temperature signal from
thermistor 420, and provides it to thermal protection module 702.
Thermal protection module 702 includes a voltage divider with
precision resistors (and thermistor 420) that correlates the
resistance of thermistor 420 to a temperature. The temperature
signal is provided to fan on/off module 704 and auxiliary power
shut down module 706.
[0038] When the temperature rises above a fan on set point, fan
on/off module 704 turns on a fan 515 (see FIG. 9), because the
control output is responsive to thermal protection module 702. The
control output provides both PWM control and thermal protection
control, and is preferably comprised of multiple conductors. When
the temperature falls below a fan off set point, fan on/off module
704 turns off fan using a fan off signal 515. Preferably, the fan
on set point is above the fan off set point, to prevent short
cycling of fan 515.
[0039] When the temperature rises above a shut down set point,
auxiliary power shut down module 706 shuts down the auxiliary power
output. Preferably, the shut down set point is above the fan on set
point. The preferred embodiment provides for turning off a relay
802 (see FIG. 8) which is in the auxiliary power output circuit.
Alternatives provide for using electronic switches (FETs, etc) in
place of relay 802, with relay 802, or in other locations to shut
off aux power.
[0040] FIG. 9 is a top view of the interior of welding type power
supply 100 and shows a wind tunnel defined by sides 501, 503, 505,
507, 509 and 511. Fan 515 cools an HF weld transformer 513 and an
aux transformer 514, along with other components. Alternatives
provide for using two or more fans.
[0041] Numerous modifications may be made to the present disclosure
which still fall within the intended scope hereof. Thus, it should
be apparent that there has been provided a method and apparatus for
providing welding and auxiliary power with thermal protection for
the aux power that fully satisfies the objectives and advantages
set forth above. Although the disclosure has been described
specific embodiments thereof, it is evident that many alternatives,
modifications and variations will be apparent to those skilled in
the art. Accordingly, the invention is intended to embrace all such
alternatives, modifications and variations that fall within the
spirit and broad scope of the appended claims.
* * * * *