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Discussion Boards => HO => Topic started by: cavemanderson on February 16, 2009, 08:35:52 PM

Title: Acela Express info needed
Post by: cavemanderson on February 16, 2009, 08:35:52 PM
Hey, does anyone know what voltage and resistance the Amtrak acela express runs at? I've got to use that information for a class and nobody's been able to find it. thanks in advance
Title: Re: Acela Express info needed
Post by: Jim Banner on February 16, 2009, 09:30:42 PM
Voltage = 0 to 12 volts, depending on desired speed.
Motor Resistance = about 12 ohms.

However, don't try to calculate motor current from the voltage applied to the motor and its resistance, unless the motor is stopped.  When it runs, the motor works like a generator and produces a counter voltage, known as Back ElectroMotive Force or bemf.  You must subtract the bemf from the applied voltage to get the effective voltage, then divide that by the resistance to get the current.  Bemf can be a high percentage of applied voltage when the motor is running freely without load, up to 95% in some cases.  Or is can decrease to virtually nothing as the load on the motor is increased.

If my assumption about why you would want to know voltage and resistance for a class was wrong, then please forgive me if you ended up learning more than you wanted to know.   
Title: Re: Acela Express info needed
Post by: Mike on February 16, 2009, 10:56:12 PM
If you mean the 1:1 version, I have been told  that there are three different voltages in different areas... 1,250 volts, 12,500 volts, and 25,000 volts. The onboard computers sense the different voltages and adjust accordingly. (probably more info than you wanted...again)- Mike