D.c. to d.c. converter

Claim 2

A d.c. to d.c. converter for coupling a d.c. source providing current at one voltage to a load adapted to utilize unidirectional current at a different voltage, said converter comprising: a resonant transformer having an input winding and an output winding, said windings being insulated from each other; a junction field-effect transistor having a pair of terminals with a substantially resistive channel circuit therebetween and a gate terminal, there being a rectifying semiconductor junction between said gate terminal and said channel circuit, the conductivity of said channel circuit being variable as a function of the voltage applied to said gate terminal with respect to said channel circuit; means connecting said primary winding in series with said channel circuit for connection across said source; means substantially directly connecting one end of said secondary winding to said gate terminal; means for connecting the other end of said secondary winding to one side of said load circuit; and means for connecting the other side of said load circuit to one side of said source, whereby said transformer is driven into resonant oscillation by said transistor and rectification, by said junction, of the oscillatory signal induced in said output winding generates a unidirectional current in said load circuit.

Claim 3

A converter as set forth in claim 1 including a tuning capacitor shunting at least one of said windings.

Claim 4

A converter as set forth in claim 1 including a filter capacitor shunting said load circuit.

Claim 5

A converter as set forth in claim 1 in which said transistor is of the depletion mode type.

Claim 6

A converter as set forth in claim 1 wherein said other side of the load circuit is connected to the side of said current source which is connected to said transistor channel circuit.

Claim 7

A d.c. to d.c. converter for coupling a d.c. source providing current at one voltage to a load adapted to utilize direct current at a different voltage, said converter comprising: a resonant transformer having an input winding and an output winding, said windings being insulated from each other; a junction field-effect transistor of the depletion mode type having source and drain terminals with a resistive channel circuit extending therebetween and a gate terminal for controlling conduction through said channel circuit, there being a rectifying semiconductor junction between said gate terminal and said channel circuit; means for connecting said source terminal to one side of said current source; means for connecting one end of said input winding to said drain terminal and the other end to the other side of said current source; a filter capacitor one end of which is connected to said one side of said current source; means connecting one side of said output winding to the other end of said capacitor; and means connecting the other side of said output winding to said gate terminal, the ends of said input and output windings connected to said transistor being oppositely polarized thereby to provide positive feedback around said transistor, whereby said transformer is driven into resonant oscillation by said transistor and rectification, by said junction, of the oscillatory signal induced in said output winding generates at said other end of said filter capacitor a d.c. voltage of polarity opposite to that applied to said input winding by said source, with respect to the potentiAl at said source terminal.

Claim 8

A d.c. to d.c. converter for coupling a d.c. source providing current at one voltage to a load adapted to utilize direct current at a different voltage, said converter comprising: a resonant transformer having an input winding and an output winding, said windings being insulated from each other; a junction field-effect transistor of the depletion mode type having source and drain terminals with a resistive channel circuit extending therebetween and a gate terminal for controlling conduction through said channel circuit, there being a rectifying semiconductor junction between said gate terminal and said channel circuit; means for connecting said source terminal to one side of said current source; means for connecting one end of said input winding to said drain terminal and the other end to the other side of said current source; a filter capacitor one end of which is connected to said one side of said current source; means connecting one side of said output winding to the other end of said capacitor; and means connecting the other side of said output winding to said gate terminal, the ends of said input and output windings connected to said transistor being oppositely polarized thereby to provide positive feedback around said transistor, whereby said transformer is driven into resonant oscillation by said transistor and rectification, by said junction, of the oscillatory signal induced in said output winding generates at said other end of said filter capacitor a d.c. voltage of polarity opposite to that applied to said input winding by said source, with respect to the potentiAl at said source terminal.

Claim 9

A converter as set forth in claim 6 including a tuning capacitor shunting one of said windings.

Claim 10

A d.c. to d.c. converter for coupling a d.c. source providing a positive potential with respect to ground to a load adapted to utilize direct current at a higher voltage, said converter comprising: a resonant transformer having an input winding and an output winding, said windings being insulated from each other, said output winding having a substantially greater number of turns than said input winding; a junction field-effect transistor of the depletion mode type having source and drain terminals with an N-type resistive channel circuit extending therebetween and a gate terminal for controlling conduction through said channel circuit, there being a rectifying P-N semiconductor junction between said gate terminal and said channel circuit; means for connecting said source terminal to ground; means for connecting one end of said input winding to said drain terminal and the other end to said positive source potential; a filter capacitor one end of which is connected to ground; means connecting one side of said output winding to the other end of said capacitor; and means connecting the other side of said output winding directly to said gate terminal, the ends of said input and output windings connected to said transistor being oppositely polarized thereby to provide positive feedback around said transistor, whereby said transformer is driven into resonant oscillation by said transistor and rectification, by said semiconductor junction, of the oscillatory signal induced in said output winding generates a negative voltage of magnitude greater than said positive voltage at said other end of the said filter capacitor.

Claim 11

A d.c. to d.c. converter for coupling a d.c. source providing a positive potential with respect to ground to a load adapted to utilize direct current at a higher voltage, said converter comprising: a resonant transformer having an input winding and an output winding, said windings being insulated from each other, said output winding having a substantially greater number of turns than said input winding; a junction field-effect transistor of the depletion mode type having source and drain terminals with an N-type resistive channel circuit extending therebetween and a gate terminal for controlling conduction through said channel circuit, there being a rectifying P-N semiconductor junction between said gate terminal and said channel circuit; means for connecting said source terminal to ground; means for connecting one end of said input winding to said drain terminal and the other end to said positive source potential; a filter capacitor one end of which is connected to ground; means connecting one side of said output winding to the other end of said capacitor; and means connecting the other side of said output winding directly to said gate terminal, the ends of said input and output windings connected to said transistor being oppositely polarized thereby to provide positive feedback around said transistor, whereby said transformer is driven into resonant oscillation by said transistor and rectification, by said semiconductor junction, of the oscillatory signal induced in said output winding generates a negative voltage of magnitude greater than said positive voltage at said other end of the said filter capacitor.