Method for guaranteeing the correct operation of a taximeter's electronic sensor

摘要

Signals from one North pole and three South poles (2) equally spaced around a shaft (1) are detected (8) and analyses (10). The positive pulses are counted (16) and sent to the analyzer (10) but not transmitted (7) to the taximeter. The negative pulses are counted (18) and the time between them measured (17). If a negative pulse is not followed by three positive pulses or the time between negative pulses varies the meter is shut down