Claims
- 1. A fuel cell system for a portable electronic device, comprising:
a fuel cell capable of operating on hydrogen that is obtained from methanol; a reservoir for storing a supply of methanol, suitably connected to the fuel cell, wherein a fuel quantity measuring means is located within the reservoir, wherein the fuel quantity measuring means comprises:
an acoustic transmitter for transmitting an acoustic signal within the reservoir, and an acoustic receiver for receiving the acoustic signal, wherein the fuel quantity measuring means is adapted to:
measure a response at the acoustic receiver, and cross reference the measured response to a lookup table which provides the corresponding fuel level.
- 2. A fuel cell system for a portable electronic device, comprising:
a fuel cell that operates on hydrogen obtained from a liquid hydrocarbon fuel; and a reservoir for containing a supply of the liquid hydrocarbon fuel, said reservoir connected to the fuel cell, wherein a sensing means for measuring the amount of liquid hydrocarbon fuel that is present is located within the reservoir, wherein the sensing means comprises:
an acoustic transmitter for transmitting an acoustic signal within the reservoir, and an acoustic receiver for receiving the acoustic signal, wherein the sensing means is adapted to:
measure a response at the acoustic receiver, and cross reference the measured response to a lookup table which provides the corresponding fuel level.
- 3. The fuel cell system as recited in claim 2, further comprising an indicia readable by a human user of the portable electronic device, wherein the indicia comprises a display for displaying the fuel level.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of pending U.S. application Ser. No. 09/906,266, filed Jul. 16, 2001, and assigned to Motorola, Inc.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09906266 |
Jul 2001 |
US |
Child |
10621199 |
Jul 2003 |
US |