Thyristor controller

• US 5,361,009 A
• Filed: 06/29/1992
• Issued: 11/01/1994
• Est. Priority Date: 06/29/1992
• Status: Expired due to Fees

• Current Assignee: Chao C. Lu
• Original Assignee: Chao C. Lu
• Inventors: Lu, Chao C.
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): TRAN, TOAN V
• Application Number:
  US07/905,881
• Time in Patent Office: 855 Days
• Field of Search: 307/631, 307/638, 307/642, 307/648, 307/305
• US Class Current: 327/470
• CPC Class Codes: H03K 17/732 Measures for enabling turn-off

Abstract

A new SCR (silicon controlled rectifier) controller characterized by comprising input circuits, SCR trigger circuits, charge circuits, commutation capacitor, discharge circuits and SCR and being constructed in such way that when the input pulse is positive, it will work to activate the trigger and cause the SCR to be in turn-on state as well as to charge the commutation capacitor and when the input pulse is zero, the stored energy of the commutation capacitor will discharge to cause the SCR to be in turn-off state so that it does not need any other electric energy to attain the objective to cut off the source.

Claims

1. A thyristor controller for connecting and disconnecting a source from a circuit, the thyristor controller comprising:

an input circuit for receiving a positive pulse charge, said input circuit comprising;

first, second and third input diodes;

an input terminal connected to said first, second and third input diodes, said input terminal receiving said positive pulse charge as an input signal; and

a current limiting resistor connected in series with said first input diode;

a thyristor having a gate connected to said current limiting resistor and capable of being in an ON state or an OFF state under control of said positive pulse charge;

a commutation capacitor connected between said second input diode and an anode of said thyristor, said commutation capacitor charging in response to receipt of said positive pulse charge by said input circuit which turns on said thyristor in accordance with an appropriate turn-on voltage of the thyristor; and

a discharge circuit connected to said third input diode and coupled to receive said positive pulse charge applied to said input circuit for discharging said commutation capacitor in response to the positive pulse charge going to zero to place said thyristor in the OFF state, wherein said discharge circuit comprises;

an inverter circuit having a collector, an emitter and a base;

a diode connected to said collector of said inverter circuit; and

a Darlington circuit coupled to said inverter circuit through said diode, said Darlington circuit comprising a plurality of thyristors.

2. A thyristor controller for connecting and disconnecting a source from a circuit, the thyristor controller comprising:

an input circuit for receiving a positive pulse charge, said input circuit comprising;

first, second and third input diodes;

an input terminal connected to said first, second and third input diodes, said input terminal receiving said positive pulse charge as an input signal; and

a current limiting resistor connected in series with said first input diode;

a thyristor having a gate connected to said current limiting resistor and capable of being in an ON state or an OFF state under control of said positive pulse charge;

a commutation capacitor connected between said second input diode and an anode of said thyristor, said commutation capacitor charging in response to receipt of said positive pulse charge by said input circuit which turns on said thyristor in accordance with an appropriate turn-on voltage of the thyristor; and

a discharge circuit connected to said third input diode and coupled to receive said positive pulse charge applied to said input circuit for discharging said commutation capacitor in response to the positive pulse charge going to zero to place said thyristor in the OFF state, wherein said discharge circuit comprises;

an inverter circuit having a collector, an emitter and a base;

a diode connected to said collector of said inverter circuit; and

a Darlington circuit coupled to said inverter circuit through said diode, said Darlington circuit comprising a single thyristor.