U.S. patent application number 11/224908 was filed with the patent office on 2006-04-13 for self-adjusting hot box.
This patent application is currently assigned to HON HAI Precision Industry CO., LTD.. Invention is credited to Mu-Chang Wang, Ning-Yu Wang.
Application Number | 20060076092 11/224908 |
Document ID | / |
Family ID | 36144094 |
Filed Date | 2006-04-13 |
United States Patent
Application |
20060076092 |
Kind Code |
A1 |
Wang; Mu-Chang ; et
al. |
April 13, 2006 |
Self-adjusting hot box
Abstract
A self-adjusting hot box includes a box (1) with a fan, a heater
(50) placed in the box (1), a thermostat (30) and a power supply
(20) applied to provide power to the fan (12), the thermostat (30)
and the heater (50). The heater (50) includes a plurality of heat
generating devices, and each of the heat generating devices
includes a plurality of power resistors (60) in electrical parallel
connection. The thermostat (30) includes a T type thermocouple (33)
disposed in the box (1), a double-acting relay (37), a temperature
controller (32) and a plurality of single-acting relays. The power
supply (20) includes a transformer (21), a bridge clipper diode
(23) and a capacitor (25).
Inventors: |
Wang; Mu-Chang; (Tu-Cheng,
TW) ; Wang; Ning-Yu; (Shenzhen, CN) |
Correspondence
Address: |
MORRIS MANNING & MARTIN LLP
1600 ATLANTA FINANCIAL CENTER
3343 PEACHTREE ROAD, NE
ATLANTA
GA
30326-1044
US
|
Assignee: |
HON HAI Precision Industry CO.,
LTD.
Tu-Cheng City
TW
|
Family ID: |
36144094 |
Appl. No.: |
11/224908 |
Filed: |
September 13, 2005 |
Current U.S.
Class: |
148/603 |
Current CPC
Class: |
F27D 21/0014 20130101;
F27B 17/02 20130101; F27B 17/0016 20130101; F27D 19/00
20130101 |
Class at
Publication: |
148/603 |
International
Class: |
C21D 9/52 20060101
C21D009/52; C21D 8/02 20060101 C21D008/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2004 |
CN |
200410051722.6 |
Claims
1. A self-adjusting hot box comprising: a box having a supporting
board disposed therein and a fan therein; a heater placed in the
box; a thermostat electrically connected with the heater for
controlling operation of the fan and the heater alternately; and a
power supply for providing power to the thermostat and the
heater.
2. The self-adjusting hot box as recited in claim 1, wherein the
heater comprises a plurality of heat generating devices, and each
heat generating device comprises a plurality of power resistors in
electrical parallel connection.
3. The self-adjusting hot box as recited in claim 2, wherein each
of the heat generating devices of the heater further comprises a
diode in electrical parallel connection with the power
resistors.
4. The self-adjusting hot box as recited in claim 1, wherein the
power supply comprises: a transformer; a bridge clipper diode; and
a capacitor; wherein an input terminal of the transformer is input
AC of 220V, an output terminal of the transformer is electrically
connected with an input terminal of the bridge clipper diode, an
output terminal of the bridge clipper diode is in electrical
parallel connection with the capacitor, and a power output terminal
of the power supply is connected with the capacitor and the bridge
clipper diode.
5. The self-adjusting hot box as recited in claim 1, wherein the
thermostat comprises a temperature sensor disposed in the box, a
double-acting relay and a temperature controller coupled with the
temperature sensor and the double-acting relay.
6. The self-adjusting hot box as recited in claim 5, wherein the
temperature controller further comprises a pilot switch connected
with the double-acting relay.
7. The self-adjusting hot box as recited in claim 5, wherein the
double-acting relay comprises a first key and a second key, the
second key is switched on when the first key is cut off, the first
key is switched on when the second key is cut off.
8. The self-adjusting hot box as recited in claim 7, wherein a
single-acting relay is connected with each heat generating device
of the heater, the single-acting relay is connected with one
terminal of the second key of the double-acting relay, and the
other terminal of the second key is connected with the power output
terminal of the power supply.
9. The self-adjusting hot box as recited in claim 1, wherein the
supporting board is net-shaped.
10. The self-adjusting hot box as recited in claim 1, wherein a
door with a handle is attached to the box, a middle portion of the
door forms a transparent glass window.
11. The self-adjusting hot box as recited in claim 1, wherein an
opening is defined in the box, and the fan is received in the
opening and connected with the thermostat.
12. A self-adjusting hot box for testing hot property of an
electrical component comprising: a box having a supporting board
disposed therein; a heater placed in the box for heating the
electrical component; a thermostat electrically connecting the
heater for controlling operation of the heater; and a power supply
for providing power to the thermostat and the heater.
13. The self-adjusting hot box as recited in claim 12, wherein the
heater comprises a plurality of heat generating devices, and each
heat generating device comprises a plurality of power resistors and
a diode in electrical parallel connection.
14. The self-adjusting hot box as recited in claim 12, wherein the
power supply comprises: a transformer; a bridge clipper diode; and
a capacitor; wherein an input terminal of the transformer is set to
be AC of 220V, an output terminal of the transformer is
electrically connected with an input terminal of the bridge clipper
diode, an output terminal of the bridge clipper diode is in
electrical parallel connection with the capacitor, and a power
output terminal of the power supply is connected with the capacitor
and the bridge clipper diode.
15. The self-adjusting hot box as recited in claim 12, wherein the
thermostat comprises a temperature sensor disposed in the box, a
double-acting relay and a temperature controller coupled with the
temperature sensor and the double-acting relay.
16. The self-adjusting hot box as recited in claim 15, wherein the
temperature controller further comprises a pilot switch connected
with the double-acting relay.
17. The self-adjusting hot box as recited in claim 15, wherein the
double-acting relay comprises a first key and a second key, the
second key is switched on when the first key is cut off, the first
key is switched on when the second key is cut off.
18. The self-adjusting hot box as recited in claim 17, wherein a
single-acting relay is connected with each heat generating device
of the heater, the single-acting relay is connected with one
terminal of the second key of the double-acting relay, and the
other terminal of the second key is connected with the power output
terminal of the power supply.
19. A method to establish a thermal test environment for an
electrical device, comprising the steps of: preparing a box with a
temperature-controllable space therein; equipping said box with a
heater capable of raising temperature of said space; ventilating
said space of said box with an outside of said box; and controlling
said temperature of said space of said box by means of said heater
and said ventilating step.
20. The method as recited in claim 19, wherein a fan is equipped on
said box to communicate said space with said outside of said box
and perform said ventilating step.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a hot box, and more
particularly to a self-adjusting hot box for testing a hot property
of an electrical device.
[0003] 2. Background of the Invention
[0004] Hot property is a sort of important properties for an
electrical device such as computer, sever, notebook and so on. Hot
property reflects an operation state of the electrical device in a
different temperature environment. When hot property of an
electrical device is tested, a kind of simulation temperature
environment is needed. Traditionally, a hot box is designed for
testing an electrical device placed therein. The temperature in the
hot box can be adjusted within a range of necessary temperature.
Consequently, the hot box provides a kind of simulation temperature
environment for testing the electrical device.
[0005] In fact, the electrical device is placed in natural
convection environment and temperature of every part of the
electrical device is approximately uniform. However, if the hot box
cannot simulate a real temperature environment, the test for hot
property of the electrical device is no effect. Understandably,
some attempts have been taken to introduce an improved hot box.
[0006] What is needed, therefore, is a self-adjusting hot box that
can simulate a real temperature environment for testing an
electrical device.
SUMMARY
[0007] A self-adjusting hot box includes a box with a fan, a heater
placed in the box, a thermostat and a power supply applied to
provide power to the fan, the thermostat and the heater. The heater
includes a plurality of heat generating devices, and each heat
generating device includes a plurality of power resistors in
electrical parallel connection. The thermostat includes a T type
thermocouple disposed in the box, a double-acting relay, a
temperature controller and a plurality of single-acting relays. The
power supply includes a transformer, a bridge clipper diode and a
capacitor. The T type thermocouple measures temperature in the box
1 and transfers the temperature to the temperature controller. The
temperature controller and the relays jointly control the fan and
the heater. The fan starts to operate and the heater is cut off
when the temperature is higher than the testing temperature. The
fan is cut off and the heater is out of service when the
temperature is lower than the testing temperature. Therefore, the
testing temperature is maintained. In addition, the heat that the
power resistors generate is a mixture of emanation heat and
radiation heat, thereby solving a problem that the heat is
non-uniformly distributed. The heat in the box is free convection,
thereby simulating the natural environment.
[0008] Other advantages and novel features of the present invention
will be drawn from the following detailed description of preferred
embodiment of the present invention with the attached drawings, in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an isometric view of a self-adjusting hot box in
accordance with a preferred embodiment of the present invention
including a box with a door, a power supply, a thermostat and a
heater;
[0010] FIG. 2 is similar to FIG. 1, but the door being open;
[0011] FIG. 3 is a functional block diagram of the self-adjusting
hot box;
[0012] FIG. 4 is a fragmentary schematic diagram of the power
supply and the thermostat as shown in FIG. 3; and
[0013] FIG. 5 is a fragmentary schematic diagram of the heater as
shown in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIG. 1, a self-adjusting hot box in accordance
with a preferred embodiment of the present invention includes a box
1 and a door 2 pivotably mounted to the box 1. A middle portion of
the door 2 forms a transparent glass window 3 for observing the
interior of the box 1 conveniently. A handle 4 is formed on the
door 2 for opening the door 2 easily. Each sidewall of the box 1
defines a recess 6 for carrying the box 1 conveniently. An opening
7 is defined in a middle portion of a top panel of the box 1, and a
fan 12 is mounted in the opening 7.
[0015] Referring to FIG. 2, a supporting board 10 is net-shaped and
disposed in the box 1 for supporting an electrical component.
[0016] Referring to FIG. 3, the self-adjusting hot box can adjust
temperature automatically by a control circuit. The control circuit
of the self-adjusting hot box includes a power supply 20, a
thermostat 30 and a heater 50.
[0017] Referring to FIG. 4, the power supply 20 includes a
transformer 21, a bridge clipper diode 23 and a capacitor 25. An
input terminal of the supply power 20 is input AC of 220V. An
output terminal of transformer 21 is connected with an input
terminal of the bridge clipper diode 23. An output terminal of the
bridge clipper diode 23 is connected in electrical parallel with
the capacitor 25 to serve as a power output terminal 27 of the
power supply 20. After transformation of the transformer 21,
rectification of the bridge clipper diode 23 and the capacitor 25,
the power output terminal 27 of the power supply 20 outputs DC of
12V that provides power to the fan 12 and heater 50.
[0018] The thermostat 30 includes a temperature controller 32, a T
type thermocouple 33, a double-acting relay 37 and a plurality of
single-acting relays 41, 43, 45, 47 in electrical parallel
connection. The T type thermostat 33 is connected with the
temperature controller 32. The temperature controller 32 is input
AC of 220V, and the temperature controller 32 includes a pilot
switch 35 connected with the double-acting relay 37. The
double-acting relay 37 includes a first key 371 and a second key
372. One terminal of the first key 371 is connected with the power
output terminal 27, and the other terminal of the first key 371 is
connected with the fan 12, thereby controlling operation of the fan
12. One terminal of the second key 372 is connected with the power
output terminal 27, and the other terminal of the second key 372 is
connected with the single-acting relays 41, 43, 45, 47. The
single-acting relays 41, 43, 45, 47 include switches 42, 44, 46, 48
respectively. Terminals of the switches 42, 44, 46, 48 are
respectively connected with the power output terminal 27, and the
other terminals of the switches 42, 44, 46, 48 are respectively K1,
K2, K3, K4.
[0019] Referring also to FIG. 5, the heater 50 includes a plurality
of heat generating devices 51, 53, 55, 57 and a plurality of
single-acting relays 41, 43, 45, 47 corresponding to the heat
generating devices 51, 53, 55, 57. Each of the heat generating
devices 51, 53, 55, 57 includes a plurality of power resistors 60
and diodes 52, 54, 56, 58 in electrical parallel connection. One
terminal of the heat generating devices 51, 53, 55, 57 and anodes
of the diodes 52, 54, 56, 58 are coupled to the output terminals
K1, K2, K3, K4 of the single-acting relays 41, 43, 45, 47, and the
other terminal of the heat generating devices 51, 53, 55, 57 and
anodes of the diodes 52, 54, 56, 58 are coupled to the
grounding.
[0020] The T type thermocouple 33 is disposed in the box 1 for
testing the temperature accurately. The heat generating devices 51,
53, 55, 57 of the heater are placed and distributed uniformly at a
bottom of the box 1 for free convection heat transfer. The other
components of the control circuit are placed in a control circuit
box (not shown). The control circuit box can be placed everywhere.
However, the control circuit box may as well be placed outside the
box 1 in view of avoiding engendering temperature error in the box
1.
[0021] In use of the self-adjusting hot box, the electrical device
is placed on the supporting board 10 and then the door 2 is closed.
The temperature controller 32 is set to a testing temperature that
is needed. The T type thermocouple 33 measures a temperature in the
box 1 and transfers the temperature signal to the temperature
controller 32. When the temperature is higher than the testing
temperature, the temperature controller 32 cuts off the pilot
switch 35 automatically. Therefore, the double-acting relay 37
controlled by the pilot switch 35 switches on the first key 371 and
cuts off the second key 372 automatically. The single-acting relays
41, 43, 45, 47 connected with the first key 371 are cut off with
the power output terminal 27, and the heater 50 is also switched
off. Simultaneously, the first key 371 is electrically connected
with the power output terminal 27, and the fan 12 is turned on so
that the temperature in the box 1 is reduced. On the contrary, when
the temperature is lower than the testing temperature, the
temperature controller 32 switches on the pilot switch 35
automatically. Accordingly, the double-acting relay 37 controlled
by the pilot controller 35 cuts off the first key 371 and switches
on the second key 372 automatically so that the fan 12 is cut off
and is out of service. Simultaneously, after the second key 372 is
switched on, the switches 42, 44, 46, 48 of the single-double
relays 41, 43, 45, 47 are switched on, and the output terminals K1,
K2, K3, K4 are electrically connected with the power output
terminal 27. Consequently, the diodes 52, 54, 56, 58 of the heat
generating devices 51, 53, 55, 57 are electrified and the power
resistors 60 start to operate and generate heat. The heat that the
power resistor 60 generates is a mixture of emanation heat and
radiation heat, thereby solving a problem that the heat is
non-uniformly distributed. In addition, the heat in the box 1 is
free convection, thereby simulating the natural environment.
[0022] Alternatively, the T type thermocouple 33 can be replaced by
other temperature sensors. In order to lower temperature rapidly,
more fans are needed. The number of heat generating device can be
decreased and increased in light of factual situation.
[0023] While the present invention has been illustrated by the
description of preferred embodiment thereof, and while the
preferred embodiment has been described in considerable details, it
is not intended to restrict or in any way limit the scope of the
appended claims to such detail. Additional advantages and
modifications within the spirit and scope of the present invention
will readily appear to those skilled in the art. Therefore, the
present invention is not limited to the specific details and
illustrative example shown and described.
* * * * *