Frequency quadrupler for anti-skid wheel speed sensor

Claim 2

In an anti-skid system, the improvement of a circuit for increasing the amount of information obtainable from a sinusoidal wheel speed transducer output, comprising a full wave rectifier connected to the transducer for producing a full wave rectified signal from the sinusoidal output signal of the transducer, the rectifier having a feed back capAcitor in shunt with a resistive feed back network to dampen the gain of the rectifier when high frequency signals are received thereby, the resistive feed back network including a thermistor causing the characteristic gain of the rectifier to vary inversely with changes in the ambient temperature; means connected to the resistive feed back network for reducing the gain of the rectifier when the amplitude of the signals received thereby exceeds a particular level; an operational amplifier connected to the rectifier and having one input biased with respect to the other, and receiving the rectified signal at the inputs thereof; and a one-shot circuit connected to the circuit means and receiving the output pulses therefrom and creating pulses of fixed amplitude and duration in response to the output pulses.

Claim 3

The improvement of a circuit for increasing the amount of information obtainable from a sinusoidal wheel speed transducer output as recited in claim 1 wherein the inputs of the operational amplifier are series connected through two diodes, the rectified signal being applied at the junction of the diodes, and wherein a voltage divider circuit is interposed between the rectifier and the junction of the diodes for clamping the lower level of the rectified signal transitions.

Claim 4

The improvement of a circuit for increasing the amount of information obtainable from a sinusoidal wheel speed transducer output as recited in claim 1, wherein said means comprises a voltage divider connected to the resistive feed back network and a resistor and diode connected to the voltage divider and in shunt with the resistive network system.

Claim 5

A circuit for creating a plurality of uniform pulses in timespaced relationship to a reference sinusoidal signal, comprising: a full wave precision rectifier receiving said sinusoidal signal and creating a full wave rectified signal therefrom, said precision rectifier including a resistive feed back network providing a characteristic gain for said rectifier and a capacitor in shunt with said resistive feed back network for diminishing the gain of said rectifier at high frequency operation, said resistive feed back network including a thermistor for making the gain of said rectifier temperature variable; an operational amplifier receiving said rectified signal, one input of the amplifier being biased with respect to another input with both inputs receiving said rectified signal, the operational amplifier producing an output pulse on each transition of said rectified signal through a particular level; a voltage divider interposed between said rectifier and said operational amplifier to limit the level of the negative going transitions of the full wave rectified signals; and a monostable multivibrator receiving said output pulses from said operational amplifier and responsive thereto to produe output signals of fixed amplitude and pulse width.

Claim 6

A circuit for creating a plurality of uniform pulses in timespaced relationship to a reference sinusoidal signal, comprising: a full wave precision rectifier receiving said sinusoidal signal and creating a full wave rectified signal therefrom, said precision rectifier including a resistive feed back network providing a characteristic gain for said rectifier and a capacitor in shunt with said resistive feed back network for diminishing the gain of said rectifier at high frequency operation, said resistive feed back network including a thermistor for making the gain of said rectifier temperature variable; an operational amplifier receiving said rectified signal, one input of the amplifier being biased with respect to another input with both inputs receiving said rectified signal, the operational amplifier producing an output pulse on each transition of said rectified signal through a particular level; a voltage divider interposed between said rectifier and said operational amplifier to limit the level of the negative going transitions of the full wave rectified signals; and a monostable multivibrator receiving said output pulses from said operational amplifier and responsive thereto to produe output signals of fixed amplitude and pulse width.

Claim 7

The circuit according to claim 4 wherein said full wave rectified signal is capacitively coupled into said operational amplifier by way of a capacitor connected between said voltage divider and said operational amplifier.

Claim 8

The circuit according to claim 4 wherein said inputs of the operational amplifier are in series connection through two diodes, the rectified signal being applied to the amplifier at the point of interconnection of said diodes.