US3821565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching circuit utilizing gate controlled switching device
Assignee: Sony Corp
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Filing: 1973-05-11
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Granted: 1974-06-28
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Expires: 1993-05-11
Abstract
Abstract A switching circuit which utilizes a gate controlled switching device (GCS) or thyristor of the gate turn-off type has its gate connected with a series connection of another switching element and a voltage source and with a current supplying means arranged in parallel to the series connection. The other switching element, which may be a GCS or transistor, has its conductivity controlled by a control signal applied thereto, and the gate controlled switching device is supplied with a turn-off gate current from the voltage source through such other switching element when the latter is conductive, whereas the gate controlled switching device is supplied with a turn-on gate current from the current supplying means when the other switching element is non-conductive.
Inventors
- 👤 H Horinaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:11
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/72; H03K17/73; H03K4/00; H03K4/06; H03K4/08; H03K4/83
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
174 words
A switching circuit, comprising a gate controlled switching device having an anode, cathode and gate for controlling the passage of a current from said anode to said cathode in dependence on a gate current flowing in a path including said gate and cathode, secondary switching means connected to said gate and having ON and OFF states, a voltage source connected in series with said secondary switching means and having its polarity arranged for providing a first gate current flowing from said cathode to said gate in said ON state of said secondary switching means, current supplying means comprising an inductor connected to said gate substantially in parallel with the series connection of said secondary switching means and said voltage source, said current supplying means providing a second gate current flowing from said gate to said cathode in the OFF state of said switching means, and means supplying a control signal to said secondary switching means for selectively controlling the ON and OFF states of said secondary switching means in accordance with said control signal.
Claim 2
Dependent Claim
174 words
A switching circuit, comprising a gate controlled switching device having an anode, cathode and gate for controlling the passage of a current from said anode to said cathode in dependence on a gate current flowing in a path including said gate and cathode, secondary switching means connected to said gate and having ON and OFF states, a voltage source connected in series with said secondary switching means and having its polarity arranged for providing a first gate current flowing from said cathode to said gate in said ON state of said secondary switching means, current supplying means comprising an inductor connected to said gate substantially in parallel with the series connection of said secondary switching means and said voltage source, said current supplying means providing a second gate current flowing from said gate to said cathode in the OFF state of said switching means, and means supplying a control signal to said secondary switching means for selectively controlling the ON and OFF states of said secondary switching means in accordance with said control signal.
Claim 3
Dependent Claim
22 words
A switching circuit according to claim 1, wherein said current supplying means further includes a resistor connected in series to said inductor.
Claim 4
Dependent Claim
31 words
A switching circuit according to claim 1, further comprising an additional inductor interposed in said path of said first gate current flowing in said ON state of said secondary switching means.
Claim 5
Dependent Claim
52 words
A switching circuit according to claim 1, wherein said secondary switching means includes a second gate controlled switching device having an anode connected to said gate of the first mentioned gate controlled switching device, a cathode connected to said voltage source and a gate connected to said means supplying said control signal.
Claim 6
Dependent Claim
40 words
A switching circuit according to claim 1, wherein said secondary switching means includes a transistor having a collector-emitter path connected to said gate of the gate controlled switching device and a base connected to said means supplying the control signal.
Claim 7
Dependent Claim
87 words
A switching circuit according to claim 1, further compriSing current sensing means interposed in a path of the current flowing from said anode to said cathode of the gate controlled switching device, and controlling means connected between said secondary switching means and said current sensing means for conditioning said secondary switching means in said ON state when said current sensing means detects a current in excess of a predetermined value, whereby to turn OFF the gate controlled switching device and protect the latter from an excess current.
Claim 8
Dependent Claim
25 words
A switching circuit according to claim 6, wherein said current sensing means includes a resistor connected to said cathode of said gate controlled switching device.
Claim 9
Dependent Claim
40 words
A switching circuit according to claim 7, wherein said controlling means includes an additional switching means which is switched in response to the output of said current sensing means for supplying a switching control signal to said secondary switching means.
Claim 10
Dependent Claim
67 words
A switching circuit according to claim 8, wherein said additional switching means includes a PNP-type transistor having an emitter connected to said cathode of the gate controlled switching means between the latter and said resistor of the current sensing means, a collector connected to said secondary switching means for turning ON the latter with an emitter-collector current flowing through said transistor, and a base connected to ground.
Claim 11
Dependent Claim
135 words
A switching circuit according to claim 8, wherein said additional switching means includes an NPN-type transistor having a collector connected through a Zener diode to said secondary switching means, an emitter connected to said cathode of the gate controlled switching means between the latter and said resistor of the current sensing means, and voltage divider means connecting said collector and the base of said transistor with the source of the anode current for said gate controlled switching means so that said transistor is made conductive and said Zener diode is turned OFF only so long as the current flowing from said anode to said cathode is below said predetermined value and, upon exceeding said predetermined value, said transistor is made non-conductive and said Zener diode is turned ON for turning ON said secondary switching means.
Claim 12
Dependent Claim
23 words
A switching circuit according to claim 1, wherein said gate controlled switching means is constituted by a thyristor of the gate turn-off type.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |