CA2019925A1 - Ptc electromechanical relay - Google Patents
Ptc electromechanical relayInfo
- Publication number
- CA2019925A1 CA2019925A1 CA 2019925 CA2019925A CA2019925A1 CA 2019925 A1 CA2019925 A1 CA 2019925A1 CA 2019925 CA2019925 CA 2019925 CA 2019925 A CA2019925 A CA 2019925A CA 2019925 A1 CA2019925 A1 CA 2019925A1
- Authority
- CA
- Canada
- Prior art keywords
- ptc
- relay
- electrical
- electrical contact
- carried
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H61/00—Electrothermal relays
- H01H61/002—Structural combination of a time delay electrothermal relay with an electrothermal protective relay, e.g. a start relay
- H01H2061/004—PTC resistor in series with start winding, e.g. adapted for being switched off after starting for limiting power dissipation
Abstract
PTC Electromechanical Relay Abstract of the Disclosure A resistor having a positive temperature coefficient (PTC) is provided in combination with an electomechanical relay as a single unit. The combination is particularly useful in starting split phase motors. The electrical contacts of the electromechanical relay are in series with the PTC. This arrangement takes the PTC
out of the circuit after starting and during running of the motor and permits the PTC to be cooled down to below its transformation temperature.
out of the circuit after starting and during running of the motor and permits the PTC to be cooled down to below its transformation temperature.
Description
~ ~ ~ 2 ~ 1 9 9 2 ~
.
, .. .
;~ ~ ; Backaround;of the Invention ~ -Thls invention relat~eJ generally~to a resistance de~ice for use~ln starting spllt phase~motors~and more~partlcularly to a PTC
reJ~l~stor in combi nat ion with~an~electromechanical relay.
PTC devices are commonly~used~ n the starting of split pbase electrical~motorJ. In;U~.~5~.~3~,925,74~8, for example, there is d~e3cr~ibed~a PTC~which~ J~connected to~the start wlnding of a split pha~é~motor;.~ Llkewlse~in . .~ t ntJ~3~,92~ 117 and 4,~67,635 t~er are deJcribed~3tructure~ of PTC d ~C-~ uJefu1~-n ~tartlng In all~ such systems~there is a problem in tbat~the PTC is alway9 in the motor circuit~and is alway~ dissipatlng wasted power.~In~addltlon lf~ ther~é~lJ~a~momentary~loJJ of~power in the c~lrcul't~the~motor~wlll~ not~automat;lcally~be:~reJtarted.~
Accord~i~ngly~it is~a~eatur~e~of~the~present invention to provlde~`a~PTC :resiJtor~ n~comblnation~with;an electromechanical ~ -relay.~ It i~s~anotber feature~o~ the~invention~to provide ~uch a combl~natlon~wherei~n;the~PTC reJlJtOr~ J;~ln serleJ ~ith~the elect~rlcal~contactJ of~the~relay.~
ummarY~of the~ I~nvention Géneral~ y~Jyeaklng~,~in~accordance~with~the inventlon there is ;provided a PTC electromechanical relay~whlch conpriseJ~a relay ;
body,~a magnetic coil~;carrlod by the~relay body,~ a relay`
e~lectrlcal contact;and~armature asJembly Jlideably carried in the ~ ;
relay bod~y~,~ a PTC resiJtor aJJembly~carrled in the relay body Including PTC-electrical start contacts~engaging the relay eIectrical contact a~sembly~to~ provide a series connection there between, ; . : : . ' ' -, 201992~ :
, . . .
, . . . .~, . .
and electrical termlnals electrically connected to the relay electrical contact a~sembly and the PTC electrlcal contact~.
When u~lng the PTC electronechanlcal relay of the -;~
lnvention in ~tartlng a split phase motor there 1~ provided a method of allowlng a PTC re~lstor to be cooled below lts tran~ormatlon temperature after startlng and durlng runnlng of the spllt phase motor whlcn comprl~es openlng electrlcal contacts : -of an electromechanical relay that are ln ~erle-~ wlth the PTC
r~lstor.
Descr~ptlon of~the Drawlnaa Figure l ls an exploded view of a combinatlon PTC and electromechanlcal relay.
~Flgur~s 2 and 3 are sectlons of the comblnatlon ta~en along -the llne 2-2 of Flgur~ 1.
Flgure 4 13 Bn exploded view of the PTC used ln the -comblnatlon.
Detailed~De3crl:ptl0n of the Invention - - - :.
Referrlng now to the drawing there is shown a PTC
electromechanical relay 10 whlch ln general lncludes a PTC
~ -, resistor 12 and an electro~echanical relay 14. Referring particularly to Figure~ l~and 4 PTC r2sistor lncludes a wafer 16 . . .
of a materlal wlth a posltlve temperature coefflclent of a type -~
well hnown in the art. For example the wsfer could be fabriciated of a conventionally doped barium ti~anate ceramic material.
Electrical terminal 18 is carried on one surface 16a of wafer 16 while electrical terminal 22 is biased against surface 16b of the wafer. Nore specifically terminal 22 i~ sandwiched between an ',` ~ ", ~
- ' , : :, :
~, . . . ..
2019~2~
;.,i,................................ . .
electrical insulator plate 24, which ls fixedly carried in body 26 of electromechanical relay 14, and wafer 16. The terminal is spring biased against surface 16 through its flange 22'. A leg 22" of the terminal extend~ through an opening 23 in insulator 24 , and carrles electrical contact 28.
Referring now to Figures 1-3~ electromechanical relay 14 incIudes a body portlon 26 whlch is closed by a cover 28. A
~magn-tlc filed coll 30~urround~the~body portion and includes a : : : :: ~ : ~, . .
plurality of turns of~copper~or alumlnum wire. Electrical contact and armature assembly 32~float ~or ls lideably carried within body 26. As shown,~the~a~sembly lncludes a magnetic steel armature 34 and a non-magnetic lug 36 that are carrled on an ~` -eyelet 38, an electrical contact~bar 40 that is loosely carried on ;
the eyelet, and a coil~sprl~ng;42~surroundlng the eyelet and carrled between the slug and tbe electr~ical contact bar.
;Electrlcal~contact bar 40~1ncludes a~palr o~ electrical contact-~
44 and 46.
: ~ : : ; - , Electrical termlna~ls~48 and 50 are~carried on an electrically ln~ulative platform tnot~sh~own~ near ~he top portion of body 26.
:: :::: :
Terminal 50 i9 e;lectrically~isolated from~wafer l6. Terminal 48 lncludes two lead connection legs 48' and 48" and also include~ an :
electrlcal contact 52.
The operation of the device can best be described in con~unction with the ~tarting and running of a ~plit phase motor.
Referrlng to Figure l, a split phase motor is shown schematically `~ -as having a start windlng 62 and a~maln winding 64. Junction 66 between the start and motor wlndlng is connected to one side of an , .
, .
.. - - , 201992~ -~ . , , . ,. ~
~C power source. The other side of the start winding is connected to terminal 18 while the other side of the main winding is connected to terminal 50. Terminal 50 is connected to one end of coil 30 (not shown). Lead 48~ is connected to the other side of the AC power source. Lead 48" is connected to the other end of -coil 30. With this arrangement the PTC i9 connected in series ~ ~ ;
with electrical contact~ 44, 46 of the electromechanical relay -when the relay~is energized.
, .
With motor 60 of~, contacts 44, 52 and 46, 28 are open tFigure 2). When motor lg started a high main winding current flow- through coil 30 to create a magnetic field and pull armature 34 in to close electrical contacts 44, 52, and 46,28 ~Figure 3).
.
The PTC is now in series w1th the electromechanical relay and a circuit is completed through the PTC and start winding 62. During thi3 time the resistance of the PTC is there between 6-10 ohms. ~ ~-Because of heating, the PTC rapidly increases in resistance such that the main winding current decreases as rotation of the motor begins and continues to accelerate. This continue3 until the point i9 reached where the main winding current drops sufficiently ~
to allow the armature to drop out and contacts 44,52 and 46,28 are ~-opened. The PTC is now DO~ longer ln the circuit. During continued rotation of the motor the PTC is allowed to coo} down below its transformation tssperature and the resistance of the PTC ,, ;~
becomes }ow. With the resistance o~ the PTC being low there would be enough current to allow the motor to restart if there is an inadvertent momentary power interruption.
" ":
.. :' "' ' ~
.
, .. .
;~ ~ ; Backaround;of the Invention ~ -Thls invention relat~eJ generally~to a resistance de~ice for use~ln starting spllt phase~motors~and more~partlcularly to a PTC
reJ~l~stor in combi nat ion with~an~electromechanical relay.
PTC devices are commonly~used~ n the starting of split pbase electrical~motorJ. In;U~.~5~.~3~,925,74~8, for example, there is d~e3cr~ibed~a PTC~which~ J~connected to~the start wlnding of a split pha~é~motor;.~ Llkewlse~in . .~ t ntJ~3~,92~ 117 and 4,~67,635 t~er are deJcribed~3tructure~ of PTC d ~C-~ uJefu1~-n ~tartlng In all~ such systems~there is a problem in tbat~the PTC is alway9 in the motor circuit~and is alway~ dissipatlng wasted power.~In~addltlon lf~ ther~é~lJ~a~momentary~loJJ of~power in the c~lrcul't~the~motor~wlll~ not~automat;lcally~be:~reJtarted.~
Accord~i~ngly~it is~a~eatur~e~of~the~present invention to provlde~`a~PTC :resiJtor~ n~comblnation~with;an electromechanical ~ -relay.~ It i~s~anotber feature~o~ the~invention~to provide ~uch a combl~natlon~wherei~n;the~PTC reJlJtOr~ J;~ln serleJ ~ith~the elect~rlcal~contactJ of~the~relay.~
ummarY~of the~ I~nvention Géneral~ y~Jyeaklng~,~in~accordance~with~the inventlon there is ;provided a PTC electromechanical relay~whlch conpriseJ~a relay ;
body,~a magnetic coil~;carrlod by the~relay body,~ a relay`
e~lectrlcal contact;and~armature asJembly Jlideably carried in the ~ ;
relay bod~y~,~ a PTC resiJtor aJJembly~carrled in the relay body Including PTC-electrical start contacts~engaging the relay eIectrical contact a~sembly~to~ provide a series connection there between, ; . : : . ' ' -, 201992~ :
, . . .
, . . . .~, . .
and electrical termlnals electrically connected to the relay electrical contact a~sembly and the PTC electrlcal contact~.
When u~lng the PTC electronechanlcal relay of the -;~
lnvention in ~tartlng a split phase motor there 1~ provided a method of allowlng a PTC re~lstor to be cooled below lts tran~ormatlon temperature after startlng and durlng runnlng of the spllt phase motor whlcn comprl~es openlng electrlcal contacts : -of an electromechanical relay that are ln ~erle-~ wlth the PTC
r~lstor.
Descr~ptlon of~the Drawlnaa Figure l ls an exploded view of a combinatlon PTC and electromechanlcal relay.
~Flgur~s 2 and 3 are sectlons of the comblnatlon ta~en along -the llne 2-2 of Flgur~ 1.
Flgure 4 13 Bn exploded view of the PTC used ln the -comblnatlon.
Detailed~De3crl:ptl0n of the Invention - - - :.
Referrlng now to the drawing there is shown a PTC
electromechanical relay 10 whlch ln general lncludes a PTC
~ -, resistor 12 and an electro~echanical relay 14. Referring particularly to Figure~ l~and 4 PTC r2sistor lncludes a wafer 16 . . .
of a materlal wlth a posltlve temperature coefflclent of a type -~
well hnown in the art. For example the wsfer could be fabriciated of a conventionally doped barium ti~anate ceramic material.
Electrical terminal 18 is carried on one surface 16a of wafer 16 while electrical terminal 22 is biased against surface 16b of the wafer. Nore specifically terminal 22 i~ sandwiched between an ',` ~ ", ~
- ' , : :, :
~, . . . ..
2019~2~
;.,i,................................ . .
electrical insulator plate 24, which ls fixedly carried in body 26 of electromechanical relay 14, and wafer 16. The terminal is spring biased against surface 16 through its flange 22'. A leg 22" of the terminal extend~ through an opening 23 in insulator 24 , and carrles electrical contact 28.
Referring now to Figures 1-3~ electromechanical relay 14 incIudes a body portlon 26 whlch is closed by a cover 28. A
~magn-tlc filed coll 30~urround~the~body portion and includes a : : : :: ~ : ~, . .
plurality of turns of~copper~or alumlnum wire. Electrical contact and armature assembly 32~float ~or ls lideably carried within body 26. As shown,~the~a~sembly lncludes a magnetic steel armature 34 and a non-magnetic lug 36 that are carrled on an ~` -eyelet 38, an electrical contact~bar 40 that is loosely carried on ;
the eyelet, and a coil~sprl~ng;42~surroundlng the eyelet and carrled between the slug and tbe electr~ical contact bar.
;Electrlcal~contact bar 40~1ncludes a~palr o~ electrical contact-~
44 and 46.
: ~ : : ; - , Electrical termlna~ls~48 and 50 are~carried on an electrically ln~ulative platform tnot~sh~own~ near ~he top portion of body 26.
:: :::: :
Terminal 50 i9 e;lectrically~isolated from~wafer l6. Terminal 48 lncludes two lead connection legs 48' and 48" and also include~ an :
electrlcal contact 52.
The operation of the device can best be described in con~unction with the ~tarting and running of a ~plit phase motor.
Referrlng to Figure l, a split phase motor is shown schematically `~ -as having a start windlng 62 and a~maln winding 64. Junction 66 between the start and motor wlndlng is connected to one side of an , .
, .
.. - - , 201992~ -~ . , , . ,. ~
~C power source. The other side of the start winding is connected to terminal 18 while the other side of the main winding is connected to terminal 50. Terminal 50 is connected to one end of coil 30 (not shown). Lead 48~ is connected to the other side of the AC power source. Lead 48" is connected to the other end of -coil 30. With this arrangement the PTC i9 connected in series ~ ~ ;
with electrical contact~ 44, 46 of the electromechanical relay -when the relay~is energized.
, .
With motor 60 of~, contacts 44, 52 and 46, 28 are open tFigure 2). When motor lg started a high main winding current flow- through coil 30 to create a magnetic field and pull armature 34 in to close electrical contacts 44, 52, and 46,28 ~Figure 3).
.
The PTC is now in series w1th the electromechanical relay and a circuit is completed through the PTC and start winding 62. During thi3 time the resistance of the PTC is there between 6-10 ohms. ~ ~-Because of heating, the PTC rapidly increases in resistance such that the main winding current decreases as rotation of the motor begins and continues to accelerate. This continue3 until the point i9 reached where the main winding current drops sufficiently ~
to allow the armature to drop out and contacts 44,52 and 46,28 are ~-opened. The PTC is now DO~ longer ln the circuit. During continued rotation of the motor the PTC is allowed to coo} down below its transformation tssperature and the resistance of the PTC ,, ;~
becomes }ow. With the resistance o~ the PTC being low there would be enough current to allow the motor to restart if there is an inadvertent momentary power interruption.
" ":
.. :' "' ' ~
Claims (4)
1. A PTC electromechanical relay comprising a relay body, a magnetic coil carried by said relay body, a relay electrical contact and armature assembly slideably carried in said relay body, a PTC resistor assembly carried in said relay body including PTC electrical contacts selectively engaging said relay electrical contact and armature assembly, and electrical terminals electrically connected to said relay and electrical contact assembly, said PTC electrical contacts, and said magnetic coil.
2. A PTC electromechanical relay according to claim 1 wherein said relay and electrical contact assembly and said PTC
electrical contacts are arranged to provide an electrical series connection between the two.
electrical contacts are arranged to provide an electrical series connection between the two.
3. A PTC electromechanical relay according to claim 1 wherein said PTC resistor assembly includes a wafer having a positive temperature coefficient, a first electrical terminal carried against a surface of said wafer, a second electrical terminal carried against and spring biased between an opposite surface of said wafer and an electrically insulative plate and having a leg extending through an opening of said electrically insulative plate, and an electrical contact carried by said leg in working relation with said electrical contact and armature assembly.
4. In a system of starting a split phase motor using a PTC
in combination with an electromechanical relay, a method of allowing said PTC to cool down below its transformation temperature after starting and during running of said split phase motor comprising opening electrical contacts of said electromechanical relay that are in series with said PTC.
in combination with an electromechanical relay, a method of allowing said PTC to cool down below its transformation temperature after starting and during running of said split phase motor comprising opening electrical contacts of said electromechanical relay that are in series with said PTC.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37415389A | 1989-06-30 | 1989-06-30 | |
| US07/374,153 | 1989-06-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2019925A1 true CA2019925A1 (en) | 1990-12-31 |
Family
ID=23475530
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2019925 Abandoned CA2019925A1 (en) | 1989-06-30 | 1990-06-27 | Ptc electromechanical relay |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2019925A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5666254A (en) * | 1995-09-14 | 1997-09-09 | Raychem Corporation | Voltage sensing overcurrent protection circuit |
| US5689395A (en) * | 1995-09-14 | 1997-11-18 | Raychem Corporation | Overcurrent protection circuit |
| US5737160A (en) * | 1995-09-14 | 1998-04-07 | Raychem Corporation | Electrical switches comprising arrangement of mechanical switches and PCT device |
| ES2117556A1 (en) * | 1996-02-23 | 1998-08-01 | Iglesias Angel Sa | Current limiting device for inductive loads. |
| US5864458A (en) * | 1995-09-14 | 1999-01-26 | Raychem Corporation | Overcurrent protection circuits comprising combinations of PTC devices and switches |
| GB2341729A (en) * | 1998-09-17 | 2000-03-22 | Rover Group | Electrical relay incorporating ptc element |
-
1990
- 1990-06-27 CA CA 2019925 patent/CA2019925A1/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5666254A (en) * | 1995-09-14 | 1997-09-09 | Raychem Corporation | Voltage sensing overcurrent protection circuit |
| US5689395A (en) * | 1995-09-14 | 1997-11-18 | Raychem Corporation | Overcurrent protection circuit |
| US5737160A (en) * | 1995-09-14 | 1998-04-07 | Raychem Corporation | Electrical switches comprising arrangement of mechanical switches and PCT device |
| US5864458A (en) * | 1995-09-14 | 1999-01-26 | Raychem Corporation | Overcurrent protection circuits comprising combinations of PTC devices and switches |
| ES2117556A1 (en) * | 1996-02-23 | 1998-08-01 | Iglesias Angel Sa | Current limiting device for inductive loads. |
| GB2341729A (en) * | 1998-09-17 | 2000-03-22 | Rover Group | Electrical relay incorporating ptc element |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |