Signal level responsive circuit

Claim 2

In a Schmitt trigger circuit including a pair of corresponding current control devices each including a pair of load terminals and a control terminal, common resistor means connected between corresponding load terminals of said current control devices and a common voltage reference point, a voltage divider network of resistance means coupled across the load terminal of one of said current control devices remote from the load terminal connected to said common resistor means and a said common voltage reference point, the control terminal of the other current control device being connected to an intermediate point of said voltage divider network wherein upon the connection of the load terminals of said current control devices to a source of DC voltage of a given polarity a signal level responsive circuit results wherein one of said current control devices is normally conducting and the other current control devices is normally nonconducting in the absence of a control signal input coupled to the control terminal of said one current control device, and the application of a control signal to the latter control terminal above an upper trip level will reverse the conductive states of said current control devices as loNg as the magnitude of said control signal does not fall below a lower trip level, the improvement comprising sources of DC voltage of said given polarity respectively connected to said load terminals of the current control devices through said common resistor means, at least one of which sources being a pulsed DC voltage source.

Claim 3

The Schmitt trigger circuit of claim 1 wherein said pulsed DC voltage source is connected to the load terminals of said other current control device, and the other source of DC voltage connected to said one current control device provides a steady DC voltage of said polarity.

Claim 4

The Schmitt trigger circuit of claim 2 wherein said source of pulsating DC voltage provide DC pulses of a fixed frequency, and the Schmitt trigger circuit is combined with a control signal source for said control terminal of said one current control device which control signal source provides spaced pulses of varying amplitude and also of the same phase as that of the output of said source of pulsating DC voltage so the circuit is operated only by pulsed control signals of the desired phase, the envelope of the pulsed waveform of said control signal source varying between said upper and lower trip levels.

Claim 5

In combination, a source of a control signal of varying instantaneous value which signal is to initiate a given control function when it varies in a first given-direction and reaches a first given level and is to terminate such function when the magnitude of the signal reverses in direction and reaches a second given level; and a signal level responsive circuit having an input connected to the output of said signal source and providing a first output condition for providing said function when the magnitude of said control signal fed thereto increases in said first given direction and reaches a given ''''turn on'''' level and providing a second output condition for terminating said function when the magnitude of said control signal fed thereto reverses in direction and reaches a given ''''turn off'''' level, thereby to provide a given overall circuit hysteresis, said signal level responsive circuit including a trigger circuit responsive to the input of the signal level responsive circuit and which effects operation of the signal level responsive circuit between said first and second output conditions when said input control signal varies between said ''''turn on'''' level and a level closer to said turn on level than said given ''''turn off'''' level said trigger circuit comprising a pair of corresponding current control devices each including a pair of load terminals and a control terminal, common resistor means connected between one of the corresponding load terminals of said current control devices and a common voltage reference point, a voltage divider network of resistance means coupled across the load terminals of one of said current control devices remote from the load terminal connected to said common resistor means and said common voltage reference point, the control terminal of the other current control device being connected to an intermediate point of said voltage divider network, wherein upon the connection of the load terminals of said current control devices to a source of DC voltage of a given polarity a signal level responsive circuit wherein one of said current control devices is normally conducting and the other current control device is normally nonconducting to effect said second output condition in the absence of a control signal input coupled to the control terminal of said one current control device and the application of a control signal to the latter control terminal at or above an upper trip level which is said ''''turn on'''' level will reverse the conductive states of said current control devices to effect said first output condition as long as the magnitude of said control signal does not fall below a lower trip level which is said level closer to said ''''turn on'''' level than said ''''turn ofF'''' level, and sources of DC voltage of said given polarity respectively connected to said load terminals of the current control devices through said common resistor means, at least one of which sources being a pulsed DC voltage source; means connecting the output of said control signal source to said control terminal of said one current control device; and control signal modifying means responsive to the operation of said signal level responsive circuit to said first output condition for modifying the signal fed to the control terminal of said one current control device to artificially vary the amplitude of the control signal fed thereto so as to provide a resultant signal which is closer to said given ''''turn on'''' level.

Claim 6

In combination, a source of a control signal of varying instantaneous value which signal is to initiate a given control function when it varies in a first given-direction and reaches a first given level and is to terminate such function when the magnitude of the signal reverses in direction and reaches a second given level; and a signal level responsive circuit having an input connected to the output of said signal source and providing a first output condition for providing said function when the magnitude of said control signal fed thereto increases in said first given direction and reaches a given ''''turn on'''' level and providing a second output condition for terminating said function when the magnitude of said control signal fed thereto reverses in direction and reaches a given ''''turn off'''' level, thereby to provide a given overall circuit hysteresis, said signal level responsive circuit including a trigger circuit responsive to the input of the signal level responsive circuit and which effects operation of the signal level responsive circuit between said first and second output conditions when said input control signal varies between said ''''turn on'''' level and a level closer to said turn on level than said given ''''turn off'''' level said trigger circuit comprising a pair of corresponding current control devices each including a pair of load terminals and a control terminal, common resistor means connected between one of the corresponding load terminals of said current control devices and a common voltage reference point, a voltage divider network of resistance means coupled across the load terminals of one of said current control devices remote from the load terminal connected to said common resistor means and said common voltage reference point, the control terminal of the other current control device being connected to an intermediate point of said voltage divider network, wherein upon the connection of the load terminals of said current control devices to a source of DC voltage of a given polarity a signal level responsive circuit wherein one of said current control devices is normally conducting and the other current control device is normally nonconducting to effect said second output condition in the absence of a control signal input coupled to the control terminal of said one current control device and the application of a control signal to the latter control terminal at or above an upper trip level which is said ''''turn on'''' level will reverse the conductive states of said current control devices to effect said first output condition as long as the magnitude of said control signal does not fall below a lower trip level which is said level closer to said ''''turn on'''' level than said ''''turn ofF'''' level, and sources of DC voltage of said given polarity respectively connected to said load terminals of the current control devices through said common resistor means, at least one of which sources being a pulsed DC voltage source; means connecting the output of said control signal source to said control terminal of said one current control device; and control signal modifying means responsive to the operation of said signal level responsive circuit to said first output condition for modifying the signal fed to the control terminal of said one current control device to artificially vary the amplitude of the control signal fed thereto so as to provide a resultant signal which is closer to said given ''''turn on'''' level.

Claim 7

The combination of claim 4 wherein said source of pulsating DC voltage provide DC pulses of a defined fixed frequency and said control signal source provides spaced pulses of varying amplitude and of the same phase as that of the output of said source of pulsating DC voltage so the circuit operated only by pulsed control signals of the desired phase, the envelope of the pulsed waveform of said control signal source varying between said upper and lower trip levels.

Claim 8

The combination of claim 5 wherein said trigger circuit is a Schmitt trigger circuit.