Claims
- 1. In a power line voltage regulator of the tap changing type including a main winding and a tapped auxiliary winding, a plurality of taps on said auxiliary winding, a pair of selector contacts for engaging the taps, a collector coupled to each selector contact, drive means for operating said selector contacts and an output terminal adapted to be coupled to a load, the improvement comprising an auxiliary system for effecting arcless engagement and disengagement of said taps by said selector contacts including first and second terminals coupled to the first and second collectors, respectively; a first selector switch for engaging one or the other of said terminals; a current switch coupled between said selector switch and said output terminal; a first thyristor circuit coupled in shunt about said current switch; a gating circuit coupled to said thyristor circuit for energizing said thyristor circuit to allow said current switch to open arclessly; current limiting impedence means; means for electrically coupling said impedance means to one of said first or second terminals and circuit switching means for coupling said impedence means in circuit between said output terminal and said first or said second collectors.
- 2. The improvement according to claim 1, wherein said means for electrically coupling comprises a second selector switch for engaging one or the other of said terminals and said circuit switching means comprises a second thyristor circuit coupled in series with said current limiting impedence means; and a second gating circuit coupled to said second thyristor circuit for enabling said thyristor circuit when said second selector switch changes position, whereby load current is temporarily conducted through said second selector switch, current limiting impedence and second thyristor circuit while said first selector switch is moved from one of said terminals to the other.
- 3. The improvement according to claim 2, further including a current transformer coupled to a line in series with said current switch; means for applying the output of said current transformer to said first gating circuit.
- 4. The improvement according to claim 3, further including an auxiliary winding electromagnetically linked to said tapped winding and coupled in series between one of said collectors and one of said therefore first or second terminals.
- 5. The improvement according to claim 1, wherein said current limiting impedence comprises a first resistor and a second resistor; said means for electrically coupling comprises a first conductor coupling said first terminal to said first resistor and a second conductor coupling said second terminal to said second resistor; said circuit switching means comprises a second thyristor circuit coupled in series with said second resistor and a third thyristor circuit coupled in series with said first resistor; and a second gating circuit for enabling said first or said second thyristor circuit.
- 6. The improvement according to claim 5, further including an auxiliary winding magnetically coupled to said tapped winding and coupled in series between one of said collectors and said second current limiting resistor.
Parent Case Info
This is a continuation of application Ser. No. 105,081, filed Dec. 19, 1979, now abandoned.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
Country |
Parent |
105081 |
Dec 1979 |
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