초록 ▼

A system for indicating the level of a liquid in a container is operable with either an analog type liquid level sensor producing an output signal which varies linearly in magnitude with the level of liquid, or a digital liquid level sensor producing a cyclic pulse width modulated signal which varie

A system for indicating the level of a liquid in a container is operable with either an analog type liquid level sensor producing an output signal which varies linearly in magnitude with the level of liquid, or a digital liquid level sensor producing a cyclic pulse width modulated signal which varies in duration according to the liquid level. One or the other type sensor is connected to an analog wire and a microprocessor is programmed to detect positive and negative going edges of pulses on the wire and generate values representing the duration of the pulses. If pulse edges are detected, the microprocessor uses the generated values representing the duration of the pulses to access a conversion table and obtain a multi-bit value for energizing the display. If no pulse edges are detected, the magnitude of the signal on the analog wire is converted to an equivalent digital value which is applied to a second conversion table to derive a multi-bit value for energizing the display. The liquid may be a fuel and the container may be the fuel tank of a vehicle.

대표청구항 ▼

[ We claim:] [1.] A liquid level indicator system including a display responsive to bits of a digital signal for indicating the level of liquid in a container, said system being operable with either an analog type liquid level sensor or a digital type liquid level sensor connected to an input wire,

[ We claim:] [1.] A liquid level indicator system including a display responsive to bits of a digital signal for indicating the level of liquid in a container, said system being operable with either an analog type liquid level sensor or a digital type liquid level sensor connected to an input wire, said system including a microprocessor programmed to determine, from a characteristic of a signal on said wire, the type of sensor connected to the wire, the microprocessor being programmed to process the signal on the wire in one way to develop the digital signal for energizing the display when it is determined that an analog type liquid level sensor is connected to the wire and in a second way to develop the digital signal for energizing the display when it is determined that a digital type liquid level sensor is connected to the wire.