Transistors power stages
AssigneeThorn Automation Limited
InventorReginald H. Whitlock
Life of this patent
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Abstract
In circuitry comprising a switching power output transistor stage and a driver transistor circuit, energy is stored in a magnetic circuit during the transistor on time to provide the turn off current. First and second magnetically coupled inductors are connected in series on the output of the driver transistor, and the base of the power transistor is connected to the junction point of the two series inductors. One or more diodes are connected in parallel with the first inductor to limit the potential drop across this inductor at turn on, and a parallel combination of at least one diode and a resistor is connected in series with the second inductor. The output stage may be two power transistors connected in a Darlington type configuration with a similar inductive circuit provided for each transistor.
Claims12
A transistor power switching stage and driver circuit comprising a driver transistor having first and second output electrodes and a control electrode, a power transistor having first and second output electrodes and a control electrode, a switching control circuit connected to the control electrode of said driver transistor, first and second magnetically coupled inductors connected in series electrically to said second output electrode of said driver transistor, a connection between the junction of said series-connected inductors and the control electrode of said power transistor, and at least one diode connected between said second output electrode of said driver transistor and said control electrode of the power transistor.
A transistor power switching stage and driver circuit comprising a driver transistor having first and second output electrodes and a control electrode, a power transistor having first and second output electrodes and a control electrode, a switching control circuit connected to the control electrode of said driver transistor, first and second magnetically coupled inductors connected in series electrically to said second output electrode of said driver transistor, a connection between the junction of said series-connected inductors and the control electrode of said power transistor, and at least one diode connected between said second output electrode of said power transistor and end terminal of said series-connected inductors remove from said second output electrode of said driver transistor.
Dependencies are inferred from the claim text.