Unijunction transistor circuit with improved recovery

Claim 2

A pulse generating circuit operable by an input signal for providing an output pulse comprising: and electrical voltage source; input signal control means supplied with voltage from said source and being operable by an input signal for proving a control signal; trigger voltage developing means responsive to said control signal for developing a triggering voltage; a negative resistance device; a circuit means connected through a portion of said input signal control means to said source for applying a supply voltage to said negative resistance device, said negative resistance device being responsive to said triggering voltage to become operative and characterized by a sudden decrease in resistance and an accompanying current flow therethrough to provide an output pulse; an improved recovery means in said circuit means for lowering said control signal when said negative resistance device is rendered operative to allow the latter to recover its inoperative state.

Claim 3

The invention defined in claim 1, wherein said improved recovery means comprises: a resistor through which said supply voltages are applied to both said negative resistance device and said input signal control nears whereby increased current flow through said resistor due to operation of said nEgative resistance device causes a voltage drop to reduce the control signal provided by said input signal control means.

Claim 4

The invention defined in claim 2, wherein said negative resistance device comprises: a unijunction transistor having its interbase voltage supplied through said resistor and having its emitter connected to said trigger voltage developing means.

Claim 5

The invention defined in claim 3, wherein: said resistor performs the additional function of lowering the interbase voltage on said unijunction transistor as a function of increase in the input signal thereby to correspondingly lower the emitter voltage at which said unijunction transistor is triggered into conduction.

Claim 6

The invention defined in claim 2, wherein said input signal control means comprises: a transistor having its emitter supplied through said resistor and its collector connected to said trigger voltage developing means to provide a controlled value of current to the latter as said control signal, and having the input signal applied across its emitter-base circuit and said resistor.

Claim 7

The invention defined in claim 5, wherein said trigger voltage developing means comprises; an RC circuit including a capacitor that is charged by said controlled value of current to develop an increasing voltage for triggering said negative resistance device.

Claim 8

A pulse generating circuit operable by an input signal for providing an output pulse comprising: an electrical voltage source; a negative resistance element; circuit means connected to said source for applying a supply voltage to said negative resistance element; trigger voltage developing means for rendering said negative resistance element operative at a controllable time after the application of a control current whereby said negative resistance element is characterized by a sudden decrease in resistance and current flow therethrough to provide an output pulse; input signal control means supplied from said source and being responsive to an adjustable input signal to provide a control current for operation of said trigger voltage developing means so as to cause it to render said negative resistance element operative as aforesaid, and adjustment of said input signal varying the time of operation of said negative resistance element; and improved recovery means in said circuit means for reducing said control current when said negative resistance element is rendered operative although said input signal continues to be applied to allow said negative resistance element to recover its inoperative condition and to terminate the output pulse.

Claim 9

A pulse generating circuit operable by an input signal for providing an output pulse comprising: an electrical voltage source; a negative resistance element; circuit means connected to said source for applying a supply voltage to said negative resistance element; trigger voltage developing means for rendering said negative resistance element operative at a controllable time after the application of a control current whereby said negative resistance element is characterized by a sudden decrease in resistance and current flow therethrough to provide an output pulse; input signal control means supplied from said source and being responsive to an adjustable input signal to provide a control current for operation of said trigger voltage developing means so as to cause it to render said negative resistance element operative as aforesaid, and adjustment of said input signal varying the time of operation of said negative resistance element; and improved recovery means in said circuit means for reducing said control current when said negative resistance element is rendered operative although said input signal continues to be applied to allow said negative resistance element to recover its inoperative condition and to terminate the output pulse.

Claim 10

The invention defined in claim 7, wherein said improved recovery means comprises: an impedance through which supply voltage is applied to both said negative resistance elements and said input signal control means so that increase in the input signal reduces the supply voltage to said negative resistance element and triggering of the latter reduces said control current provided by said input signal control means.

Claim 11

A negative resistance circuit with improved recovery means comprising: a solid state negative resistance device having a pair of main terminals and a control terminal and being characterized by an operation including a sudden decrease in resistance accompanied by an increase in current flow at one of its main terminals when the voltage at its control terminal is increased to a predetermined value, said predetermined value being a function of the voltage applied across its main terminals; an electrical voltage source; trigger voltage developing means connected to said control terminal; input signal control means operable by an adjustable input signal for providing a control signal to said trigger voltage developing means to cause operation thereof to provide a voltage increasing to said predetermined value; circuit means connected to said source for providing supply voltage to both said input signal control meanS and said solid state negative resistance device; and said circuit means comprising means responsive to operation of said solid state negative resistance device for lowering said control signal to allow the latter to recover its inoperative state.

Claim 12

A negative resistance circuit with improved recovery means comprising: a solid state negative resistance device having a pair of main terminals and a control terminal and being characterized by an operation including a sudden decrease in resistance accompanied by an increase in current flow at one of its main terminals when the voltage at its control terminal is increased to a predetermined value, said predetermined value being a function of the voltage applied across its main terminals; an electrical voltage source; trigger voltage developing means connected to said control terminal; input signal control means operable by an adjustable input signal for providing a control signal to said trigger voltage developing means to cause operation thereof to provide a voltage increasing to said predetermined value; circuit means connected to said source for providing supply voltage to both said input signal control meanS and said solid state negative resistance device; and said circuit means comprising means responsive to operation of said solid state negative resistance device for lowering said control signal to allow the latter to recover its inoperative state.

Claim 13

The invention defined in claim 9, wherein said means responsive to operation of said solid state negative resistance device for lowering said control signal to allow the latter to recover its inoperative state comprises: means responsive to increase in the input signal for lowering the supply voltage applied to said solid state negative resistance device to afford triggering thereof at a lower trigger voltage.