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US5861787A Expired / Lapsed US ⏱️ 0.0 years remaining

Reverse power protection circuit and relay

Assignee: Agilent Technologies Inc
•
Filing: 1997-06-16
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Granted: 1999-01-19
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Expires: 2017-06-16
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Abstract

Abstract A relay for high frequency instruments and a reverse power protection circuit for high frequency instruments are described herein. The relay is inexpensive to construct, permits good impedance matching up to approximately 5 GHz, and can be easily mounted on a coplanar waveguide transmission line. The circuit can open the relay in response to a reverse power condition in as little as 8 microseconds and provides both good grounding and functions reliably up to 4 GHz.

Inventors

  • 👤 Roger R. Graeber

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 13:18
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0007; H05K9/002; H05K9/0039; H01; H01H; H01H51/00; H01H51/28; H02; H02H; H02H3/00; H02H3/003; H05K9/0066

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 204 words
A reverse power protection circuit comprising: a first and second reverse biased diodes coupled respectively between a signal line and a first and second AC grounding patch; a first and second plurality of capacitors coupled between the AC grounding patch and a first and second ground plane; a first and second transient absorber coupled respectively between the AC grounding patch and the ground plane; a resistive voltage divider network coupled to at least one of the AC grounding patches and a first comparator, the first comparator having a predefined voltage trigger threshold; a flip-flop circuit for providing a logic signal output when the threshold of the first comparator is exceeded; a first transistor coupled through an inverter to the flip-flop circuit, the first transistor acting as a switch and changing state in response to the logic signal output of the flip-flop circuit; a second transistor coupled to the first transistor, the second transistor acting as a switch and changing state in response to the first transistor's changing state; and a relay having an input and output, the relay being opened and closed by the de-energizing and energizing of a electromagnetic coil in the relay, the coil being de-energized when the second transistor changes state.
Claim 2
Dependent Claim 204 words
A reverse power protection circuit comprising: a first and second reverse biased diodes coupled respectively between a signal line and a first and second AC grounding patch; a first and second plurality of capacitors coupled between the AC grounding patch and a first and second ground plane; a first and second transient absorber coupled respectively between the AC grounding patch and the ground plane; a resistive voltage divider network coupled to at least one of the AC grounding patches and a first comparator, the first comparator having a predefined voltage trigger threshold; a flip-flop circuit for providing a logic signal output when the threshold of the first comparator is exceeded; a first transistor coupled through an inverter to the flip-flop circuit, the first transistor acting as a switch and changing state in response to the logic signal output of the flip-flop circuit; a second transistor coupled to the first transistor, the second transistor acting as a switch and changing state in response to the first transistor's changing state; and a relay having an input and output, the relay being opened and closed by the de-energizing and energizing of a electromagnetic coil in the relay, the coil being de-energized when the second transistor changes state.
Claim 3
Dependent Claim 52 words
The reverse power protection circuit of claim 1 wherein a one-shot circuit is coupled to the flip-flop circuit, the one-shot circuit preventing the flip-flop circuit from oscillating after it is first triggered if a reverse power signal is being received when a reset signal is applied to the reverse power protection circuit.
Claim 4
Dependent Claim 42 words
The reverse power protection circuit of claim 1 wherein the second transistor further comprises a high voltage transistor and a high voltage zener diode coupled in parallel across the high voltage transistor, the combination decreasing the time required to open the relay.

References Cited (Backward Citations)

US5198697A Cited
US5258731A Cited
US5381297A Cited
US5684441A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-01-18 2002-07-20 2003-01-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-01-18 2006-07-20 2007-01-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-01-18 2010-07-20 2011-01-19 $7700.00 Window Closed / Lapsed

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