Circuit and method for paralleling power transistors
AssigneeEVC, Inc.
InventorGeorge D. Carlsen, II
Life of this patent
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Abstract
A circuit and method of paralleling power transistors connected as a Darlington circuit or device for use with electric motor controls. The circuit is comprised of a plurality of Darlington devices having a drive circuit from a motor controller connected to a common base connection and a plurality of active pull-down circuits for reducing the rise and fall times and effectively controlling the storage times of the power transistors. The active pull-down circuits are capacity coupled to an inverted drive signal to synchronize the turn-off time and speed-up discharge of storage in the power transistor circuit.
Claims11
A high-current switching transistor circuit comprising:
- a first Darlington device;
- at least one other Darlington device;
- said Darlington devices being connected in a parallel pin-for-pin configuration;
- drive source means for driving said Darlington devices said drive source means being directly connected to an input common base connection of all of said Darlington devices;
- first pull-down circuit means connected to said common base connection of the Darlington devices to reduce the storage time of power transistor in said Darlington devices;
- at least one other pull-down circuit means connected to a base to emitter connection in each Darlington device for synchronizing the turn-off times of said Darlington devices while further reducing the storage time of said power transistors.
A method for parallel connection of a plurality of high-current switching transistors connected as Darlington devices, comprising:
- connecting a plurality of said Darlington devices in a pin-for-pin parallel configuration;
- directly coupling an input base connection of all of said Darlington devices in a common base configuration;
- simultaneously discharging the commonly connected bases and base to emitter connections in said Darlington devices;
- and
- synchronizing the turn-off time of said Darlington devices.
Dependencies are inferred from the claim text.