Start-stop oscillator control circuit

Claim 2

A circuit for exercising a control function in response to receipt of an input signal including: means for storing a potential which can be varied; means for providing a reference potential of at least one magnitude, the reference potential and stored potential being related so that the reference potential is sometimes positive and sometimes negative with respect to the stored potential; means responsive to a difference between the reference potential and the stored potential for varying the stored potential at a predetermined rate; and means responsive to receipt of the input signal for changing the stored potential at a rate significantly more rapid than the predetermined rate to a first predetermined value whenever the reference potential is positive relative to the stored potential at the time the input signal is received and for changing the stored potential at a rate significantly more rapid than the predetermined rate to a second predetermined value whenever the reference potential is negative relative to the store potential at the time the input signal is received.

Claim 3

A circuit according to claim 1 wherein the potential storing means is a capacitor.

Claim 4

A circuit according to claim 1 wherein the potential changing means is a transistor, the collector of which is connected to the potential storing means and the emitter of which is connected to the means for providing a reference potential.

Claim 5

A circuit for exercising a control function in response to receipt of an input bias signal of one of two possible magnitudes including: a capacitor charged to a potential; means for providing a reference potential of at least one magnitude; and a transistor, having at least base, collector and emitter electrodes, the collector electrode being connected to the capacitor, the emitter electrode being connected to the reference potential so that the application of the input bias signal of the one magnitude to the base of the transistor renders the transistor conductive to charge the capacitor toward the value of the reference potential if the relative values of the reference potential and the capacitor potential forward-bias the transistor and to charge the capacitor toward the potential of the input bias signal through the forward-biased base-collector junction of the transistor if the relative values of the reference potential and the capacitor potential back bias the transistor.

Claim 6

A circuit for exercising a control function in response to receipt of an input bias signal of one of two possible magnitudes including: a capacitor charged to a potential; means for providing a reference potential of at least one magnitude; and a transistor, having at least base, collector and emitter electrodes, the collector electrode being connected to the capacitor, the emitter electrode being connected to the reference potential so that the application of the input bias signal of the one magnitude to the base of the transistor renders the transistor conductive to charge the capacitor toward the value of the reference potential if the relative values of the reference potential and the capacitor potential forward-bias the transistor and to charge the capacitor toward the potential of the input bias signal through the forward-biased base-collector junction of the transistor if the relative values of the reference potential and the capacitor potential back bias the transistor.

Claim 7

A circuit according to claim 4 wherein the magnitude of the capacitor potential is between a predetermined maximum positive potential and a predetermined maximum negative potential and wherein the two possible magnitudes of the input bias signal are greater than said maximum potentials.

Claim 8

A circuit according to claim 4 wherein the transistor is an NPN transistor and the one magnitude of said bias signal is a positive potential, the magnitude of which exceeds the maximum positive potential to which the capacitor may be charged.

Claim 9

An astable multivibrator including: an operational amplifier having first and second inputs with a positive feedback path from the output thereof to said first input and with said output varying between predetermined positive and negative states; a timing capacitor connected to said second input of the amplifier; means for charging the timing capacitor from the output of the amplifier, which switches from one output state to its other output state whenever a predetermined relationship exists between the input voltage applied to the second input by the capacitor and the input voltage applied to the first input by means of the positive feedback from the output of the amplifier; normally nonconductive means connected to the capacitor and to the positive feedback path and rendered conductive in response to an external signal for clamping the charge on the capacitor to a first predetermined value, said clamping Means operating to rapidly charge the capacitor to said first predetermined value if said capacitor already is charging toward said first predetermined value at the time the clamping means is rendered conductive, and said clamping means operating to rapidly charge said capacitor to a second predetermined value if said capacitor already is charging toward said second predetermined value at the time the clamping means is rendered conductive, so that said predetermined relationship is attained to cause the amplifier to switch states, whereupon the clamping means operates to rapidly charge the capacitor to said first predetermined value; and means for applying external signals to the clamping means.

Claim 10

An astable multivibrator including: an operational amplifier having first and second inputs with a positive feedback path from the output thereof to said first input and with said output varying between predetermined positive and negative states; a timing capacitor connected to said second input of the amplifier; means for charging the timing capacitor from the output of the amplifier, which switches from one output state to its other output state whenever a predetermined relationship exists between the input voltage applied to the second input by the capacitor and the input voltage applied to the first input by means of the positive feedback from the output of the amplifier; normally nonconductive means connected to the capacitor and to the positive feedback path and rendered conductive in response to an external signal for clamping the charge on the capacitor to a first predetermined value, said clamping Means operating to rapidly charge the capacitor to said first predetermined value if said capacitor already is charging toward said first predetermined value at the time the clamping means is rendered conductive, and said clamping means operating to rapidly charge said capacitor to a second predetermined value if said capacitor already is charging toward said second predetermined value at the time the clamping means is rendered conductive, so that said predetermined relationship is attained to cause the amplifier to switch states, whereupon the clamping means operates to rapidly charge the capacitor to said first predetermined value; and means for applying external signals to the clamping means.

Claim 11

A circuit according to claim 7 wherein the feedback path includes a second operational amplifier connected as a voltage-follower.

Claim 12

A multivibrator according to claim 7 wherein the clamping means is a normally nonconductive transistor, the collector-emitter path of which is connected between the feedback path and said second input of the amplifier.

Claim 13

A multivibrator according to claim 9 wherein the external signals bias the transistor into conduction, provided the transistor is forward-biased by the voltages obtained from the feedback path and the capacitor so that the capacitor rapidly is charged to said first predetermined value at which it is clamped so long as the transistor remains biased into conduction, said transistor base-collector junction being forward-biased by said biasing means when the transistor is reversed-biased by the voltages obtained from the feedback path and the capacitor so that the capacitor rapidly is charged through the base-collector junction of the transistor to said second predetermined value sufficient to cause the operational amplifier output to switch from one output state to the other, whereupon the collector-emitter junction of the transistor substantially immediately becomes forward-biased, permitting the capacitor to discharge to said first predetermined value through the collector-emitter junction of the transistor.