← Back to Patent Explorer
US4484256A Expired / Lapsed US ⏱️ 0.0 years remaining

Constant current density high voltage power supply

Assignee: Xerox Corp
•
Filing: 1982-04-07
•
Granted: 1984-11-20
•
Expires: 2002-04-07
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A pulsed high voltage variable duty cycle current generator is described. One embodiment comprises a constant current power supply cyclically driving either one or both halves of a transformer primary. The transformer primary is polarized so that there is a secondary current output pulse proportional to the value of primary current only when one half of the primary is driven. The secondary current is rectified, and the average dc secondary current valve is used to control the primary driver duty cycle so that the secondary average current is maintained at a predetermined level. Thus, the output is a series of current pulses where the output peak value is determined by the amount of constant primary current and the output average value is determined by the output duty cycle. A second embodiment is disclosed where the peak output current is controlled by the duty cycle of the primary high frequency current pulses and where the output duty cycle is controlled by turning the primary circuit on and off at a low frequency at an adjustable duty cycle.

Inventors

  • 👤 John T. Hartman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 07:28
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/337; H02M3/3376; H02M3/3378

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 120 words
A power supply which converts a dc voltage input into a series of relatively lower frequency rectangular current regulated variable duty cycle output pulses comprising: a transformer comprising a primary and a secondary, means for periodically inducing relatively higher frequency current pulses into said primary, means for rectifying and filtering the secondary voltage which is in the form of said relatively higher frequency pulses to produce a dc current, means responsive to the instantaneous current in said secondary for varying the amplitude of the primary current pulses to regulate the output current, and means for periodically disabling said pulses at said primary at a relatively lower frequency to produce a relatively lower frequency rectangular current waveshape at said secondary output.
Claim 2
Dependent Claim 120 words
A power supply which converts a dc voltage input into a series of relatively lower frequency rectangular current regulated variable duty cycle output pulses comprising: a transformer comprising a primary and a secondary, means for periodically inducing relatively higher frequency current pulses into said primary, means for rectifying and filtering the secondary voltage which is in the form of said relatively higher frequency pulses to produce a dc current, means responsive to the instantaneous current in said secondary for varying the amplitude of the primary current pulses to regulate the output current, and means for periodically disabling said pulses at said primary at a relatively lower frequency to produce a relatively lower frequency rectangular current waveshape at said secondary output.
Claim 3
Dependent Claim 20 words
The power supply of claim 1 wherein said means for varying controls the duty cycle of the primary current pulses.
Claim 4
Dependent Claim 38 words
The power supply of claim 1 wherein said means for disabling can be adjusted to vary the duty cycle at the output of the power supply, thereby varying the average output current without varying the instantaneous output current.

References Cited (Backward Citations)

US3670234A Cited
US3742330A Cited
US3701937A Cited
US4025863A Cited
US4121282A Cited
US4005352A Cited
US4150424A Cited
US4244015A Cited
US4272806A Cited
US4371917A Cited
US4330816A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-11-20 1988-05-21 1988-11-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-11-20 1992-05-21 1992-11-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-11-20 1996-05-21 1996-11-20 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag