# [EVDL] Alternator driven by wheel or axleshaft?



## EVDL List (Jul 27, 2007)

Hello Andy,

Some alternators need about 1000 rpm to excited it. Normally a engine has a 
6 inch pulley and the alternator has a 3 inch pulley, so if the engine is up 
to 500 rpm, then the alternator is at 1000 rpm.

Lets say the transmission 1st gear is about a 4:1 ratio, than your motor rpm 
would have to be 4000 rpm for a 1000 rpm out put. Now if you have a further 
reduction of about 8:1, then the alternator will excited at 500 motor rpm.

Axles only go about 1000 rpm if your motor is at about 6000 rpm with a 10:1 
overall gear ratio which is about 100 miles per hour.

A drive line after the transmission has about a 2000 rpm limit in 1st gear. 
You want to able to have your alternator generating power as soon as 
possible by keeping the overall gear ratio as low as possible while you are 
doing low speed driving of 30 mph or under or the alternator will never come 
up to voltage.

It may be possible to add a motor shaft extension on your motor. This is 
done by drilling a hole for the same size motor shaft, in the motor face. 
The shaft is tapped for a harden threaded stud like the type that is use for 
engine heads. The shaft extension is also tapped in the extension shaft. 
Use a as large as stud as possible which will be in the range of 9/16 to 5/8 
inch bolt thread size.

You can use a seal around the shaft, something like a transmission output 
seal.

You then can put on a solid steel industrial pulley that is about 6 inches 
in diameter. It is best to a use a cog belt, because it will wear better in 
making the transition from the 3 to 6 inch.

Some people with ADC motors have done this shaft extension, which is 
normally call the motor pilot shaft.

Roland




----- Original Message ----- 
From: <[email protected]>
To: "EV List Submissions" <[email protected]>
Sent: Sunday, March 02, 2008 9:07 PM
Subject: [EVDL] Alternator driven by wheel or axleshaft?


> Hi Gang - hope you can help me with this quandry
>
> I'm scared out of my wits to try again with a DC/DC after something went
> wrong with my first one and fried my controller. This is an Azure AC
> drive kit that requires 12v input - the controller is not isolated from
> ground.
>
> CC Power replaced the converter, but I've left it in the box.
>
> The Azure motor does not have a rear output, so My new idea is to drive
> an alternator off the right driveshaft (FWD Mazda 323) or one of the
> rear wheels. Has anyone tried a setup like this? Successfully? What
> parts did you use? Please send pictures.
>
>
> IF I should stick with the DC/DC kit, is there a package I could buy
> that would assure that no high voltage crosses over? I hear folks
> mention diodes, etc, but I want something engineered by someone other
> than me!
>
>
> Thanks all!
> Andy
> Ames, IA
>
> www.evalbum.com/1473
>
>
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> 

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## EVDL List (Jul 27, 2007)

> On 2 Mar 2008 at 21:07, [email protected] wrote:
> 
> > I'm scared out of my wits to try again with a DC/DC after something went
> > wrong with my first one and fried my controller. This is an Azure AC
> ...


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