Back to results
US 5,395,078 AGranted
Low speed wheel presence transducer for railroads with self calibration
AssigneeServo Corporation of America
InventorEdward P. Gellender
Life of this patent
Estimating the term…
Abstract
A railroad car wheel transducer includes a coil positioned along a rail of a track. The presence of a wheel proximal to the coil causes basic electrical characteristics of the coil, such as its inductance and Q factor to change, which is sensed and used to generate a coil signal. A calibrating circuit monitors the coil characteristics to compensate for long term drifts.
Claims16
A wheel presence transducer comprising:
- wheel detector means for generating a wheel detection signal;
- an amplifier having an input receiving said wheel detection signal and an offset signal and an output for generating an amplifier output signal corresponding to the difference between said wheel detection and offset signal, said amplifier output signal being indicative of a detected wheel;
- and
- offset signal generating means including a comparator for comparing said amplifier output signal to a preselected range and a counter responsive to said comparator for generating said offset signal when said amplifier output signal is outside said preselected range whereby said amplifier corrects said output signal with said offset signal to eliminate drifting.
1 more element
A wheel transducer comprising:
- wheel detector means for generating a wheel detection signal;
- an amplifier having an input receiving said wheel detection signal and an offset signal and an output for generating an amplifier output signal;
- and
- offset signal generating means for generating said offset signal when said amplifier output signal is outside a preselected range whereby said amplifier corrects said output signal with said offset signal to eliminate drifting;
- wherein said offset signal generating means includes comparator means for comparing said amplifier output signal to a preselected value to generate a comparator signal and a signal generator generating said offset signal corresponding to said comparator signal;
- and
- wherein said signal generator includes a counter responsive to said comparator for generating a count.
4 more elements
A wheel transducer comprising:
- wheel detector means for generating a wheel detection signal in the presence of a wheel;
- an amplifier having a first input receiving said wheel detection signal, a second input receiving an offset signal and an output for generating an output signal;
- offset signal generating means for generating said offset signal when said amplifier output signal is outside a first preselected range whereby said amplifier corrects said output signal with said offset signal;
- and
- offset disabling means generating an offset disabling signal for disabling said offset signal generating means when said wheel is detected.
2 more elements
Dependencies are inferred from the claim text.