US4055783A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spark source with regulation of spark magnitude by control of spark timing
Assignee: Wisconsin Alumni Research Foundation
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Filing: 1976-03-01
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Granted: 1977-10-25
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Expires: 1996-03-01
Abstract
Abstract The disclosed spark source is adapted to generate electrical sparks to produce light for spectroscopic analysis of materials placed on the spark gap electrodes or introduced into the sparks. The disclosed spark source comprises a high voltage transformer having a secondary winding for supplying alternating current at a high voltage, a storage capacitor, a charging circuit including a rectifier connected between the secondary winding and the capacitor for charging the capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between the capacitor and the spark gap electrodes for discharging the capacitor across the spark gap and control means for supplying a sequence of variably spaced triggering pulses to the input means of the electronic switching device for producing a sequence of spark cycles in which the capacitor is charged to substantially the same voltage for all of the spark cycles. During the intervals between sparks, the capacitor is recharged by the transformer and the rectifier. The timing of the sparks is varied, with reference to the phase angle of the alternating current, so that the capacitor is charged to the same voltage during each of the intervals between sparks. The timing of the sparks is computed to accommodate the variation in the instantaneous voltage developed by the transformer during such intervals. By varying the timing of the sparks, it is possible to vary the voltage to which the capacitor is charged, over a wide range. The electronic switching device may comprise a thyratron in parallel with a shunting diode, to carry the oppositely polarized half-cycles of the oscillatory capacitor discharge current. An inductance element may be connected in series with the thyratron to improve the commutation between the thyratron and the shunting diode. It is also advantageous to insert an inductance element in series with the shunting diode to bring about a further improvement in such commutation.
Inventors
- 👤 John P. Walters
- 👤 David M. Coleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:33
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/53; H03K3/55; G; G01; G01N; G01N21/00; G01N21/62; G01N21/66; G01N21/67; H01; H01J; H01J17/00; H01J2893/00; H01J2893/0059
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
174 words
A spark source, comprising a high voltage transformer having a secondary winding for supplying alternating current at a high voltage, a storage capacitor, a charging circuit including a rectifier connected between said secondary winding and said capacitor for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between said capacitor and said spark gap electrodes for discharging said capacitor across said spark gap, said electronic switching device having input means for receiving triggering signals, and control means for supplying a sequence of variably spaced triggering pulses to said input means for producing a sequence of spark cycles in which said capacitor is charged to substantially equal voltages for all of said spark cycles, said control means including variable timing means responsive to the phase angle of the alternating current supplied to said high voltage transformer for varying the timing of each triggering pulse in response to the phase angle variation of the alternating current during the interval subsequent to the preceding triggering pulse.
Claim 2
Dependent Claim
174 words
A spark source, comprising a high voltage transformer having a secondary winding for supplying alternating current at a high voltage, a storage capacitor, a charging circuit including a rectifier connected between said secondary winding and said capacitor for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between said capacitor and said spark gap electrodes for discharging said capacitor across said spark gap, said electronic switching device having input means for receiving triggering signals, and control means for supplying a sequence of variably spaced triggering pulses to said input means for producing a sequence of spark cycles in which said capacitor is charged to substantially equal voltages for all of said spark cycles, said control means including variable timing means responsive to the phase angle of the alternating current supplied to said high voltage transformer for varying the timing of each triggering pulse in response to the phase angle variation of the alternating current during the interval subsequent to the preceding triggering pulse.
Claim 3
Dependent Claim
35 words
A spark source according to claim 1, in which said variable timing means includes a zero crossing detector, and means for supplying alternating current power to said high voltage transformer and said zero crossing detector.
Claim 4
Dependent Claim
35 words
A spark source according to claim 2, in which said variable timing means includes a phase angle detector, and means for supplying alternating current power to said high voltage transformer and said phase angle detector.
Claim 5
Independent Claim
77 words
A method of producing successive sparks for spectroscopic analysis, by discharging a capacitor across a spark gap, recharging the capacitor from a rectified alternating voltage source, and repeating the discharging and charging operations, while timing the discharging of the capacitor in each instance to occur when the capacitor has been recharged to a particular voltage, the timing of the discharging of the capacitor being done in relation to the phase angle of the rectified alternating voltage source.
Claim 6
Independent Claim
77 words
A method of producing successive sparks for spectroscopic analysis, by discharging a capacitor across a spark gap, recharging the capacitor from a rectified alternating voltage source, and repeating the discharging and charging operations, while timing the discharging of the capacitor in each instance to occur when the capacitor has been recharged to a particular voltage, the timing of the discharging of the capacitor being done in relation to the phase angle of the rectified alternating voltage source.
Claim 7
Dependent Claim
149 words
A spark source, comprising a high voltage transformer having a secondary winding for supplying alternating current at a high voltage, a storage capacitor, a charging circuit including a rectifier connected between said secondary winding and said capacitor for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between said capacitor and said spark gap electrodes for discharging said capacitor across said spark gap, said electronic switching device having input means for receiving triggering signals, and control means for supplying a sequence of variably spaced triggering pulses to said input means for producing a sequence of spark cycles in which said capacitor is charged to substantially equal voltages for all of said spark cycles, said control means including variable timing means for producing each triggering pulse at a time when said capacitor has been charged to a particular voltage.
Claim 8
Dependent Claim
149 words
A spark source, comprising a high voltage transformer having a secondary winding for supplying alternating current at a high voltage, a storage capacitor, a charging circuit including a rectifier connected between said secondary winding and said capacitor for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between said capacitor and said spark gap electrodes for discharging said capacitor across said spark gap, said electronic switching device having input means for receiving triggering signals, and control means for supplying a sequence of variably spaced triggering pulses to said input means for producing a sequence of spark cycles in which said capacitor is charged to substantially equal voltages for all of said spark cycles, said control means including variable timing means for producing each triggering pulse at a time when said capacitor has been charged to a particular voltage.
Claim 9
Dependent Claim
47 words
A spark source according to claim 5, in which said variable timing means includes phase detector means, means for supplying said transformer and said phase detector means with alternating current power, and means responsive to said phase detector means for deriving the timing of each triggering pulse.
Claim 10
Dependent Claim
18 words
A spark source according to claim 6, in which said phase detector means includes a zero crossing detector.
Claim 11
Independent Claim
97 words
A method of producing successive sparks for spectroscopic analysis, by discharging a capacitor across a spark gap, recharging the capacitor from a rectified alternating voltage source, and repeating the discharging and charging operations, while timing the discharging of the capacitor in each instance to occur when the capacitor has been recharged to a particular voltage, the timing of the discharging of the capacitor being done in relation to the phase angle of the rectified alternating voltage source by computing the timing from said phase angle and the elapsed time subsequent to the previous discharging of the capacitor.
Claim 12
Independent Claim
97 words
A method of producing successive sparks for spectroscopic analysis, by discharging a capacitor across a spark gap, recharging the capacitor from a rectified alternating voltage source, and repeating the discharging and charging operations, while timing the discharging of the capacitor in each instance to occur when the capacitor has been recharged to a particular voltage, the timing of the discharging of the capacitor being done in relation to the phase angle of the rectified alternating voltage source by computing the timing from said phase angle and the elapsed time subsequent to the previous discharging of the capacitor.
Claim 13
Dependent Claim
155 words
A spark source, comprising a storage capacitor, charging means for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including inductance means and an electronic switching device connected in series with said capacitor and said spark gap, said electronic switching device being operable between a nonconductive state and a unidirectionally conductive state to discharge said capacitor through said inductance means and across said spark gap, a shunting diode connected in parallel with said electronic switching device and polarized to be unidirectionally conductive in a direction opposite to the conductive direction of said electronic switching device, said capacitor and said inductance means producing an oscillatory discharge current which is conducted in one direction by said electronic switching device and in the opposite direction by said shunting diode, and second inductance means in series with said electronic switching device for improving the commutation between said electronic switching device and said shunting diode.
Claim 14
Dependent Claim
155 words
A spark source, comprising a storage capacitor, charging means for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including inductance means and an electronic switching device connected in series with said capacitor and said spark gap, said electronic switching device being operable between a nonconductive state and a unidirectionally conductive state to discharge said capacitor through said inductance means and across said spark gap, a shunting diode connected in parallel with said electronic switching device and polarized to be unidirectionally conductive in a direction opposite to the conductive direction of said electronic switching device, said capacitor and said inductance means producing an oscillatory discharge current which is conducted in one direction by said electronic switching device and in the opposite direction by said shunting diode, and second inductance means in series with said electronic switching device for improving the commutation between said electronic switching device and said shunting diode.
Claim 15
Dependent Claim
16 words
A spark source according to claim 9, in which said electronic switching device comprises a thyratron.
Claim 16
Dependent Claim
18 words
A spark source according to claim 9, in which said electronic switching device comprises a gaseous switching tube.
Claim 17
Dependent Claim
33 words
A spark source according to claim 9, including third inductance means in series with said shunting diode for producing additional improvement in the commutation between said electronic switching device and said shunting diode.
Claim 18
Dependent Claim
39 words
A spark source according to claim 9, in which said second inductance means has sufficient inductance to maintain said electronic switching device in a conductive state during the half-cycles when said shunting diode is carrying the capacitor discharge current.
Claim 19
Dependent Claim
37 words
A spark source according to claim 13, in which said third inductance means has sufficient inductance to maintain conduction in said shunting diode during the half-cycles when said electronic switching device is carrying the capacitor discharge current.
Claim 20
Dependent Claim
187 words
A spark source, comprising a high voltage transformer having a primary winding and a high voltage secondary winding, means for supplying alternating current to said primary winding, a storage capacitor, a charging circuit including a rectifier connected between said secondary winding and said capacitor for supplying high voltage rectified pulses to said capacitor for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between said capacitor and said spark gap electrodes for discharging said capacitor across said spark gap, said electronic switching device having input means for receiving triggering signals, and control means for supplying a sequence of triggering pulses to said input means for producing a sequence of spark cycles in which said capacitor is charged by said charging circuit and then is discharged through said electronic switching device and across said spark gap, said control means including variable timing means for varying the timing of each of said triggering pulses with respect to the phase angle of the alternating current to vary the voltage to which said capacitor is charged for each spark discharge.
Claim 21
Dependent Claim
187 words
A spark source, comprising a high voltage transformer having a primary winding and a high voltage secondary winding, means for supplying alternating current to said primary winding, a storage capacitor, a charging circuit including a rectifier connected between said secondary winding and said capacitor for supplying high voltage rectified pulses to said capacitor for charging said capacitor, spark gap electrodes having a spark gap therebetween, a discharge circuit including an electronic switching device connected between said capacitor and said spark gap electrodes for discharging said capacitor across said spark gap, said electronic switching device having input means for receiving triggering signals, and control means for supplying a sequence of triggering pulses to said input means for producing a sequence of spark cycles in which said capacitor is charged by said charging circuit and then is discharged through said electronic switching device and across said spark gap, said control means including variable timing means for varying the timing of each of said triggering pulses with respect to the phase angle of the alternating current to vary the voltage to which said capacitor is charged for each spark discharge.
Claim 22
Dependent Claim
62 words
A spark source according to claim 15, in which said control means includes means for producing one of said triggering pulses corresponding to each of said high voltage pulses supplied by said charging circuit to said capacitor, said timing means being operative to vary the timing of each of said triggering pulses with respect to the phase angle of said alternating current.
Claim 23
Dependent Claim
78 words
A spark source according to claim 16, in which said control means includes pulse generating means for producing said triggering pulses, said timing means including variable phase shifting means, means for supplying said alternating current to said variable phase shifting means, and phase detecting means connected between said phase shifting means and said pulse generating means for varying the timing of said triggering pulses in response to the shifting of the phase by said variable phase shifting means.
Claim 24
Dependent Claim
66 words
A spark source according to claim 15, in which said control means includes pulse generating means for producing a plurality of said triggering pulses corresponding to each of said high voltage pulses supplied to said capacitor by said charging circuit, said timing means including means for varying the timing of each of said plurality of pulses with respect to the phase angle of said alternating current.
Claim 25
Dependent Claim
71 words
A spark source according to claim 15, in which said control means includes pulse generating means for producing a plurality of said triggering pulses corresponding to each of said high voltage rectified pulses supplied by said charging circuit to said capacitor, said timing means including a plurality of variable means for individually varying the timing of said plurality of triggering pulses with respect to the phase angle of said alternating current.
Claim 26
Dependent Claim
118 words
A spark source according to claim 15, in which said control means includes pulse generating means for producing a plurality of said triggering pulses corresponding to each of said high voltage rectified pulses supplied by said charging circuit to said capacitor, said timing means including a phase angle detector, means for supplying said alternating current to said phase angle detector, said phase angle detector including means for producing phase locking pulses corresponding to the phase angle of said alternating current, and variable means connected between said phase angle detector and said pulse generating means for individually varying the timing of each of said plurality of said triggering pulses with respect to the timing of said phase locking pulses.
Claim 27
Dependent Claim
117 words
A spark source according to claim 15, in which said control means includes pulse generating means for producing a plurality of said triggering pulses corresponding to each of said high voltage rectified pulses supplied by said charging circuit to said capacitor, said timing means including a phase angle detector, means for supplying said alternating current to said phase angle detector, said phase angle detector including means for producing phase locking pulses corresponding to the phase angle of said alternating current, and a plurality of individually variable delay elements connected between said phase angle detector and said pulse generating means for individually varying the delay between the phase locking pulses and each of said plurality of triggering pulses.
Claim 28
Dependent Claim
19 words
A spark source according to claim 21, in which each of said delay elements comprises a variable monostable multivibrator.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |