Apparatus and process for automatically calibrating locomotive speedometers as wheel size varies
US4945753A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1989 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Dec 11, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P21/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A speedometer system for automatically calibrating a speedometer by adjusting the speedometer drive to take into account the varying wheel sizes of a locomotive which comprises: at least one speed probe; a speedometer drive; a speedometer; a gate for enabling and disabling the normal speed signal from the speed probe; a programmable counter for transmitting a test speed signal to the speedometer drive to produce a test speed current; a gate for enabling and disabling the transmission of the test speed signal to the speedometer drive; and a microprocessor which is capable of processing a signal representative of wheel size, calculating a test signal frequency, causing the counter to create and transmit the test signal, measuring the speedometer current, and signaling a digital potentiometer to increase or decrease the resistance on the speedometer drive until a full scale current value is measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.