CA1039808A - High energy gas discharge switching device - Google Patents
High energy gas discharge switching deviceInfo
- Publication number
- CA1039808A CA1039808A CA230,111A CA230111A CA1039808A CA 1039808 A CA1039808 A CA 1039808A CA 230111 A CA230111 A CA 230111A CA 1039808 A CA1039808 A CA 1039808A
- Authority
- CA
- Canada
- Prior art keywords
- tube
- switching device
- electrode
- electrodes
- energy
- 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.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
- H03K3/53—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback
- H03K3/55—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback the switching device being a gas-filled tube having a control electrode
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N1/00—Electrotherapy; Circuits therefor
- A61N1/18—Applying electric currents by contact electrodes
- A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
- A61N1/38—Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
- A61N1/39—Heart defibrillators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J17/00—Gas-filled discharge tubes with solid cathode
- H01J17/02—Details
- H01J17/36—Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J17/00—Gas-filled discharge tubes with solid cathode
- H01J17/38—Cold-cathode tubes
- H01J17/40—Cold-cathode tubes with one cathode and one anode, e.g. glow tubes, tuning-indicator glow tubes, voltage-stabiliser tubes, voltage-indicator tubes
- H01J17/44—Cold-cathode tubes with one cathode and one anode, e.g. glow tubes, tuning-indicator glow tubes, voltage-stabiliser tubes, voltage-indicator tubes having one or more control electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/54—Igniting arrangements, e.g. promoting ionisation for starting
- H01J61/547—Igniting arrangements, e.g. promoting ionisation for starting using an auxiliary electrode outside the vessel
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
- H01J61/80—Lamps suitable only for intermittent operation, e.g. flash lamp
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T1/00—Details of spark gaps
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2893/00—Discharge tubes and lamps
- H01J2893/0064—Tubes with cold main electrodes (including cold cathodes)
- H01J2893/0065—Electrode systems
- H01J2893/0068—Electrode systems electrode assembly with control electrodes, e.g. including a screen
Abstract
ABSTRACT OF THE DISCLOSURE
High energy switching device, for example, a defibril-lator to a patient's heart, utilizing a gas discharge tube with input and output electrodes connected electrically in series with a source and a load; a control element is connected to the input electrode, and a trigger signal is applied to the control element to initiate firing of the tube to pass energy from the source to the load; an electrostatic shield is disposed about the output electrode to prevent the tube from self firing in the absence of a trigger signal when the potential between the electrodes is below a predetermined level.
High energy switching device, for example, a defibril-lator to a patient's heart, utilizing a gas discharge tube with input and output electrodes connected electrically in series with a source and a load; a control element is connected to the input electrode, and a trigger signal is applied to the control element to initiate firing of the tube to pass energy from the source to the load; an electrostatic shield is disposed about the output electrode to prevent the tube from self firing in the absence of a trigger signal when the potential between the electrodes is below a predetermined level.
Description
~98~E~
This invention pertains generally to high energy switch-ing devices and more particularly to high energy swltching devices utilizing gas discharge tubes.
Heretofore, Xenon flash tubes and other gas discharge tubes have been utilized for switching large amounts of power by connecting the electrodes of the tube electrically in series with a source and load and applying a trigger pulse to a control terminal to break down the gas and initiate the main discharge to transfer energy from the source to the load. Such switches will handle voltages on the order of lOKV and currents on the order of several hundred amperes, and they can be switched at very high speeds. - ;
In the past, high energy switches utilizing gas dis-charge tubes have had a serious limitation in that the tubes have erratic hold-off potentials which typically range from less than 8KV to more than 25KV. Consequently, if the source voltages is 8KV or more, the device may fire by itself, and this sel~-firing cannot be tolerated in many applications, for example, de~ibril-lators where the device is used to control the application of a defibrillating pulse to a patient's heart.
In the high energy switching device of the invention, an electrostatic shield is placed about the output electrode of the gas discharge tube. It has been observed that this shield results in a highly reliable hold-off potential on the order of 15 KV with Xenon flash tubes which are available com~
mercially.
It is in general an object of the invention to provide a new and improved high energy switching device.
Another object of the invention is to provide a switch-ing device of the above character which has a highly reliablehold-off potential and i9 suitable for use in a defibrillator.
,., ~ , .
11:3398(~8 Another object of the invent.ion is to provide a switch- . .
ing device of the above character which is fail safe in operation. .
According to the invention there is provided in a high energy switching device for delivering energy from a source to a load: a gas discharge tube having first and second electrodes connected electrically in series with the source and the load, a control element connected to the first electrode, means for applying a trigger signal to the control element to initiate firing of the tube to pass energy from the source to the load, and means comprising an electrostatic shield disposed about the .
second electrode for preventing the tube from firing in the ~;
absence of a trigger signal when the potential between the ~ :
electrodes is below a predetermined level.
Additional objects and features of the invention will be apparent from the following description in which the .
.preferred embodiment is set forth in detail in conjunction with the accompanying drawing5, ;~ ~
~39!313!8 Figure 1 is a vertical sectional view of one embodiment of a high energy switching device according to the invention.
Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1.
Figure 3 is a circuit diagram of the switching device of Figure 1 employed in a defibrillator.
': ' . . . . ,: . ~ . , :
: . .. : . . - . .. . . .
.~ r-1.~398Q8 ~igure 4 i~ a graphical representation Or the out-put voltage produced by ths switching device in the circuit Or Figure 3 Description of the Pref~rrecl Embodiment , The switching de~rice includes a gas discharge tube 10 having an elongated glass envelope 11 in which axi~lly sp~ced electrodes 12 and 13 are enclosed. The envelope is filled with a suitable gas such as Xenon. In the pre~erred embodiment the tube is a Xenon ~lash tube, and the pressure -~
within the tube is slightly leas than atmospheric pressure, for example A trigger element 16 is provided ~or breaking down the gas in tube 10 and initiating the main discharge between electrodes 12 and 13. The trigger element comprises oonduc~
tive loops 16a and 16b which are disposed coaxially of the electrodes and connected to electrode 12. The loops are sp~ced ax;ally apart, with loop 16a adjacent to el'ectrode 12 and loop 16b midway between the electrodes.
Tube 10 and trigger element 16 are enclosed within ~;
20 a generally cyclindrical housing 21 ~abricated of an elec-trically insulative material such as plastic. The tube and - trigger element are disposed coaxially o~ the housing and sup-ported by suitable means, not shown. In the preferred embodi-ment, the tube has a diameter on the order o~ 1/4 to 3/8 inch, 25 the housing has a diameter on the order of 1 inah, and loops 16a~ 16b are slightly smaller in diameter than the housing.
An electrostatic shield 23 is disposed coaxially about electrode 13. The shield i9 f`abricated of an elec-trically conductive material, and in the preferred embodiment 30 it consists of a layer o:~ brass ~oil having a width of 1 inch :: -4-.. .. . ....
D -5b~, ,. ~ `
'1~3~
and a thickness on the order of .002 to .003 inch wr~ppod about the end of housing 21 at which electrode 13 is locatsd.
The shield i9 provided with an air gap 24 to prevent it ~rom being a shorted turn. I~ desired, the shield can be covered by suitable insulating material such as a rubber boot.
In Figure 3, the switching device i9 illustrated in connection with a de~ibrillator having output terminals or paddles 26,27 adapted to ba placed in contact with a patient's body for delivering a defibrillating pulse to the patient's heart. Paddle 26 is connected to electrode 13, which serve~
as an output electrode, and paddle 27 is connected to shield 24 and to a capacitor 31.
Capacitor 31 and the secondary winding 32 of a transformer are connected electrically in series between pad-15 dle 27 and input electrode 12. Capacitor 31 serves as a stor-age capacitor for the energy to be delivered to the patient' 9 heart, and it i9 cbarged from a 24 volt battery 33 to a level on the order of 3KV to 7KV by a DC-to-DC converter 34 through a diode 36.
Winding 32 is the secondary winding of a transformer 37 which also ha3 a primary winding 38. In the preferred em-bodiment, primary winding 38 oonsists of four to five turns o~ copper sheet, aecondary winding 32 consists of several hundred turns of copper wire, and the transformer is enclosed in a cylindrical aase 39 and mounted coaxially of housing 21 adjacent to input electrode 12 and trigger element 16.
Means is provided for applying trigger pulses to trigger element 16 through transformer 37. This means in-cludes a capacitor 41 and a silicon controlled rectifier 42 which are cormected electrically in series with primary wind-..
D-56B~
., .
~ 3 9~
ing 38~ Capacitor 41 is charged to a suitable triggering level, such as 200 volts, rrom battery 33 b~ a converter ~3 similar to converter 34. The gate of SCR 42 is connected to a suitable control device such as a manually operated switch.
Operation and use Or the switching device can be described briefly. Capacitor 41 is charged to a level on the order of 200 volts by converter 43 when the unit is turned on.
When converter 34 is energized, capacitor 31 is charged to a level on the order of 3KV to 7KV. Paddles 26 and 27 are placed in contact with the patient's body, and SCR 42 is fired when a defibrillating pulse is desired. When thé SCR
fires, capacitor 41 discharges through primary winding 38, producing a trigger pulse on the order of 25KV and 1-2 micro-seconds duration in secondary winding 32. This pulse ionizes tbe ga9 in tube 10, initiating the main diacharge bet~een elec-trodes 12 and 13 to deliver the energy stored in capacitor ~1 to paddles 26 and 27.
Capacitcr 31, winding 32 and the patient's bod~
eonstitute an LCR circuit which produce~ the waveform shown in ~igure 4 when capacitor 31 discharges. This waveform is oommonly known as a Lown waveform, and it is a slightly under-dampea sinusoidal wave~orm wbich decreases in magnitude at a rate on the order of 82% per hal~ cycle, Tubs 10 requires a certain minimum current to sustain ignition, and it extin-guishes on the zero cros~ing at the end of the first or sec-ond half cyele of the output voltageg depending on the level to which capacitor 31 is initially charged. With an initial eharge of 7KV, for exampleJ the voltage drop at the first zero erossing i9 very rapid, and the tube does not turn off until the second zero crossing. With a smaller initial charge, D-56~5 ~ID398~P8 e.g., 3KV, the tube extinguishes on the ~ir~t zero crossing.
The pulse delivered to thepatient 1 9 heart has a duration on the order of 5 to 8 milliseconds ancl a level depending upon the initial charge on capacitor 31.
It has been ~ound that electro~tatic shield 2~ i9 very erfective in preventing the discharge tube from firing before the trigger pulse is appliedq With the shie~d, tubes which otherwise would break down with potentials as low as 8KV will consistently and reliably hold off potentials on the order of 15KV. Prior to ignition, the ~hield is maintained at substantialIy the same potential as the output electrode and it is believed to perform its functïon by shaping the electrostatic field in the region o~ the output electrode and `
relieving the field gradient concentration which would other-wise occur in tbi~ region due to the sharpness of the elec-trodeO This ahield has been found to perform its function even when the tube i9 fired in the presence of external metal ob-~ects.
The switching device is fail safe in operation in th~t it will not ~ire in the event that the envelope is bro-ken, Trigger element 16 is 3paced a substantial distance from electrode 13 and shield 24, and it cannot arc over to either of tbem in the event the tube should break in such a manner that the electrode 13 is left exposed, In the event of a leak or crack in the envelope, the negative pressure to which the tube is filled will cause the Xenon gas to mix with the incoming air which will cauae the hold off voltage to increase.
It i9 apparent from the foregoing that a new and im-proved high energy switching device has been provided. While only the preferred embodiment has been described, as will be . - - - . . .
D -56~5 , . :
~ 9~
apparent to thos~ ~Dmiliar with -the ~rt, cert~in ch~nges and modi~ications c~n be made without departing ~rom the scope ~r the invention ~s de~ined by the ~ollowing cl~ims~
.' , :
,~
', .. . . . : ., -
This invention pertains generally to high energy switch-ing devices and more particularly to high energy swltching devices utilizing gas discharge tubes.
Heretofore, Xenon flash tubes and other gas discharge tubes have been utilized for switching large amounts of power by connecting the electrodes of the tube electrically in series with a source and load and applying a trigger pulse to a control terminal to break down the gas and initiate the main discharge to transfer energy from the source to the load. Such switches will handle voltages on the order of lOKV and currents on the order of several hundred amperes, and they can be switched at very high speeds. - ;
In the past, high energy switches utilizing gas dis-charge tubes have had a serious limitation in that the tubes have erratic hold-off potentials which typically range from less than 8KV to more than 25KV. Consequently, if the source voltages is 8KV or more, the device may fire by itself, and this sel~-firing cannot be tolerated in many applications, for example, de~ibril-lators where the device is used to control the application of a defibrillating pulse to a patient's heart.
In the high energy switching device of the invention, an electrostatic shield is placed about the output electrode of the gas discharge tube. It has been observed that this shield results in a highly reliable hold-off potential on the order of 15 KV with Xenon flash tubes which are available com~
mercially.
It is in general an object of the invention to provide a new and improved high energy switching device.
Another object of the invention is to provide a switch-ing device of the above character which has a highly reliablehold-off potential and i9 suitable for use in a defibrillator.
,., ~ , .
11:3398(~8 Another object of the invent.ion is to provide a switch- . .
ing device of the above character which is fail safe in operation. .
According to the invention there is provided in a high energy switching device for delivering energy from a source to a load: a gas discharge tube having first and second electrodes connected electrically in series with the source and the load, a control element connected to the first electrode, means for applying a trigger signal to the control element to initiate firing of the tube to pass energy from the source to the load, and means comprising an electrostatic shield disposed about the .
second electrode for preventing the tube from firing in the ~;
absence of a trigger signal when the potential between the ~ :
electrodes is below a predetermined level.
Additional objects and features of the invention will be apparent from the following description in which the .
.preferred embodiment is set forth in detail in conjunction with the accompanying drawing5, ;~ ~
~39!313!8 Figure 1 is a vertical sectional view of one embodiment of a high energy switching device according to the invention.
Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1.
Figure 3 is a circuit diagram of the switching device of Figure 1 employed in a defibrillator.
': ' . . . . ,: . ~ . , :
: . .. : . . - . .. . . .
.~ r-1.~398Q8 ~igure 4 i~ a graphical representation Or the out-put voltage produced by ths switching device in the circuit Or Figure 3 Description of the Pref~rrecl Embodiment , The switching de~rice includes a gas discharge tube 10 having an elongated glass envelope 11 in which axi~lly sp~ced electrodes 12 and 13 are enclosed. The envelope is filled with a suitable gas such as Xenon. In the pre~erred embodiment the tube is a Xenon ~lash tube, and the pressure -~
within the tube is slightly leas than atmospheric pressure, for example A trigger element 16 is provided ~or breaking down the gas in tube 10 and initiating the main discharge between electrodes 12 and 13. The trigger element comprises oonduc~
tive loops 16a and 16b which are disposed coaxially of the electrodes and connected to electrode 12. The loops are sp~ced ax;ally apart, with loop 16a adjacent to el'ectrode 12 and loop 16b midway between the electrodes.
Tube 10 and trigger element 16 are enclosed within ~;
20 a generally cyclindrical housing 21 ~abricated of an elec-trically insulative material such as plastic. The tube and - trigger element are disposed coaxially o~ the housing and sup-ported by suitable means, not shown. In the preferred embodi-ment, the tube has a diameter on the order o~ 1/4 to 3/8 inch, 25 the housing has a diameter on the order of 1 inah, and loops 16a~ 16b are slightly smaller in diameter than the housing.
An electrostatic shield 23 is disposed coaxially about electrode 13. The shield i9 f`abricated of an elec-trically conductive material, and in the preferred embodiment 30 it consists of a layer o:~ brass ~oil having a width of 1 inch :: -4-.. .. . ....
D -5b~, ,. ~ `
'1~3~
and a thickness on the order of .002 to .003 inch wr~ppod about the end of housing 21 at which electrode 13 is locatsd.
The shield i9 provided with an air gap 24 to prevent it ~rom being a shorted turn. I~ desired, the shield can be covered by suitable insulating material such as a rubber boot.
In Figure 3, the switching device i9 illustrated in connection with a de~ibrillator having output terminals or paddles 26,27 adapted to ba placed in contact with a patient's body for delivering a defibrillating pulse to the patient's heart. Paddle 26 is connected to electrode 13, which serve~
as an output electrode, and paddle 27 is connected to shield 24 and to a capacitor 31.
Capacitor 31 and the secondary winding 32 of a transformer are connected electrically in series between pad-15 dle 27 and input electrode 12. Capacitor 31 serves as a stor-age capacitor for the energy to be delivered to the patient' 9 heart, and it i9 cbarged from a 24 volt battery 33 to a level on the order of 3KV to 7KV by a DC-to-DC converter 34 through a diode 36.
Winding 32 is the secondary winding of a transformer 37 which also ha3 a primary winding 38. In the preferred em-bodiment, primary winding 38 oonsists of four to five turns o~ copper sheet, aecondary winding 32 consists of several hundred turns of copper wire, and the transformer is enclosed in a cylindrical aase 39 and mounted coaxially of housing 21 adjacent to input electrode 12 and trigger element 16.
Means is provided for applying trigger pulses to trigger element 16 through transformer 37. This means in-cludes a capacitor 41 and a silicon controlled rectifier 42 which are cormected electrically in series with primary wind-..
D-56B~
., .
~ 3 9~
ing 38~ Capacitor 41 is charged to a suitable triggering level, such as 200 volts, rrom battery 33 b~ a converter ~3 similar to converter 34. The gate of SCR 42 is connected to a suitable control device such as a manually operated switch.
Operation and use Or the switching device can be described briefly. Capacitor 41 is charged to a level on the order of 200 volts by converter 43 when the unit is turned on.
When converter 34 is energized, capacitor 31 is charged to a level on the order of 3KV to 7KV. Paddles 26 and 27 are placed in contact with the patient's body, and SCR 42 is fired when a defibrillating pulse is desired. When thé SCR
fires, capacitor 41 discharges through primary winding 38, producing a trigger pulse on the order of 25KV and 1-2 micro-seconds duration in secondary winding 32. This pulse ionizes tbe ga9 in tube 10, initiating the main diacharge bet~een elec-trodes 12 and 13 to deliver the energy stored in capacitor ~1 to paddles 26 and 27.
Capacitcr 31, winding 32 and the patient's bod~
eonstitute an LCR circuit which produce~ the waveform shown in ~igure 4 when capacitor 31 discharges. This waveform is oommonly known as a Lown waveform, and it is a slightly under-dampea sinusoidal wave~orm wbich decreases in magnitude at a rate on the order of 82% per hal~ cycle, Tubs 10 requires a certain minimum current to sustain ignition, and it extin-guishes on the zero cros~ing at the end of the first or sec-ond half cyele of the output voltageg depending on the level to which capacitor 31 is initially charged. With an initial eharge of 7KV, for exampleJ the voltage drop at the first zero erossing i9 very rapid, and the tube does not turn off until the second zero crossing. With a smaller initial charge, D-56~5 ~ID398~P8 e.g., 3KV, the tube extinguishes on the ~ir~t zero crossing.
The pulse delivered to thepatient 1 9 heart has a duration on the order of 5 to 8 milliseconds ancl a level depending upon the initial charge on capacitor 31.
It has been ~ound that electro~tatic shield 2~ i9 very erfective in preventing the discharge tube from firing before the trigger pulse is appliedq With the shie~d, tubes which otherwise would break down with potentials as low as 8KV will consistently and reliably hold off potentials on the order of 15KV. Prior to ignition, the ~hield is maintained at substantialIy the same potential as the output electrode and it is believed to perform its functïon by shaping the electrostatic field in the region o~ the output electrode and `
relieving the field gradient concentration which would other-wise occur in tbi~ region due to the sharpness of the elec-trodeO This ahield has been found to perform its function even when the tube i9 fired in the presence of external metal ob-~ects.
The switching device is fail safe in operation in th~t it will not ~ire in the event that the envelope is bro-ken, Trigger element 16 is 3paced a substantial distance from electrode 13 and shield 24, and it cannot arc over to either of tbem in the event the tube should break in such a manner that the electrode 13 is left exposed, In the event of a leak or crack in the envelope, the negative pressure to which the tube is filled will cause the Xenon gas to mix with the incoming air which will cauae the hold off voltage to increase.
It i9 apparent from the foregoing that a new and im-proved high energy switching device has been provided. While only the preferred embodiment has been described, as will be . - - - . . .
D -56~5 , . :
~ 9~
apparent to thos~ ~Dmiliar with -the ~rt, cert~in ch~nges and modi~ications c~n be made without departing ~rom the scope ~r the invention ~s de~ined by the ~ollowing cl~ims~
.' , :
,~
', .. . . . : ., -
Claims (19)
1. In a high energy switching device for delivering energy from a source to a load: a gas discharge tube having first and second electrodes connected electrically in series with the source and the load, a control element connected to the first electrode, means for applying a trigger signal to the control element to initiate firing of the tube to pass energy from the source to the load, and means comprising an electrostatic shield disposed about the second electrode for preventing the tube from firing in the absence of a trigger signal when the potential between the electrodes is below a predetermined level.
2. The switching device of claim 1, wherein the gas dis-charge tube is a Xenon flash tube.
3. The switching device of claim 1, wherein the tube com-prises an elongated envelope with the electrodes spaced toward opposite ends thereof.
4. The switching device of claim 3, wherein the control element and the electrostatic shield are disposed toward the same ends of the envelopes the electrodes with which they are associated.
5. The switching device of claim 4, wherein the control element comprises a pair of conductible loops disposed coaxially of the electrodes.
6. The switching device of claim 5, wherein one of the control elements loops is positioned adjacent to the first electrode and the second loop is positioned between the electrodes.
7. The switching device of Claim 1 wherein the means for applying the trigger signal comprises a transformer having a secondary winding connected electrically in series with the source and the first electrode.
8. The switching device of Claim 1 wherein the source comprises a storage capacitor.
9. The switching device of Claim 8 further includ-ing a battery and means for delivering a high energy charge to the capacitor from the battery.
10. The switching device of Claim 1 wherein the pressure within the tube is substantially equal to atmos-pheric pressure.
11. The switching device of Claim 1 wherein the tube includes an elongated envelope, the shield is mounted coaxial-ly of the electrodes toward one end of the envelope, and the control element comprises a pair of conductive loops disposed coaxially of the electrodes toward the second end of the en-velope, the loops being of substantially different diameter than the tube.
12. In a device for delivering a high energy pulse to a load connected to a pair of output terminals: a gas discharge tube having an elongated envelope with axially spaced input and output electrodes disposed toward the ends of the envelope, means connecting the output electrode to a first one of the output terminals, a trigger element connec-ted to the input electrode and disposed toward the same end of the envelope as said electrode, an electrostatic shield connected to the second output terminal and disposed coax-ially of the output electrode, an energy storage device, means for delivering energy to the storage device, a trans-former having primary and secondary windings, means connect-ing the energy storage device and the secondary winding of the transformer electrically in series with the input electrode and the second output terminal, and means for delivering a trigger pulse to the primary winding of the transformer to initiate firing of the tube to deliver the energy from the storage device to the load connected to the output terminals.
13. The device of Claim 12 wherein the gas discharge tube is a Xenon flash tube.
14. The device of Claim 12 wherein the energy stor-age device is a capacitor.
15. The device of Claim 14 wherein the means for delivering energy to the capacitor constituting the storage device comprises a battery and a converter powered by the battery for delivering a high voltage charge to the capacitor.
16. The device of Claim 12 wherein the means for delivering the trigger pulse comprises a capacitor and switch-ing means for delivering energy stored in the capacitor to the primary winding.
17. The device of Claim 12 wherein the output ter-minals are defibrillator paddles.
18. The device of Claim 12 wherein the transformer is disposed coaxially about the input electrode.
19. The switching device of Claim 12 wherein the pressure within the tube is substantially equal to atmos-pheric pressure.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US48311474A | 1974-06-26 | 1974-06-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1039808A true CA1039808A (en) | 1978-10-03 |
Family
ID=23918719
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA230,111A Expired CA1039808A (en) | 1974-06-26 | 1975-06-25 | High energy gas discharge switching device |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS512976A (en) |
| CA (1) | CA1039808A (en) |
| DE (1) | DE2528203C2 (en) |
| FR (1) | FR2276683A1 (en) |
| GB (1) | GB1469050A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5043634A (en) * | 1988-06-27 | 1991-08-27 | Gte Products Corporation | Pulsed light source |
| JPH08504893A (en) * | 1992-10-14 | 1996-05-28 | ウール リサーチ オーガナイゼイション オブ ニュー ジーランド インコーポレイテッド | Bulky multi-fiber yarn |
-
1975
- 1975-04-08 GB GB1442075A patent/GB1469050A/en not_active Expired
- 1975-04-30 JP JP50051624A patent/JPS512976A/en active Granted
- 1975-06-16 FR FR7518714A patent/FR2276683A1/en active Granted
- 1975-06-25 DE DE2528203A patent/DE2528203C2/en not_active Expired
- 1975-06-25 CA CA230,111A patent/CA1039808A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2276683A1 (en) | 1976-01-23 |
| DE2528203A1 (en) | 1976-01-15 |
| JPS512976A (en) | 1976-01-12 |
| DE2528203C2 (en) | 1981-09-24 |
| JPS5419577B2 (en) | 1979-07-16 |
| FR2276683B1 (en) | 1980-07-18 |
| GB1469050A (en) | 1977-03-30 |
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