Friday, July 10, 2009

RE: [Electric Boats] Re: Relays to replace a controller



DC motor speed controllers also fail ON since some or many are using FET
outputs and when they go, they often fail shorted.

So it's always good to have a mechanical disconnect that you can physically
PULL that disconnects power.

I knew a guy who built an EV car that had its Curtis controller fail ON at a
Stop sign.

Even with mechanical main power disconnect, he was halfway thru the
intersection before he was able to pull the power.

So be sure you are a short distance away from a physical mechanical ripcord
power removal at all times.

-Myles

From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com]
On Behalf Of ruffles_85006
Sent: Friday, July 10, 2009 6:26 AM
To: electricboats@yahoogroups.com
Subject: [Electric Boats] Re: Relays to replace a controller

I have prviously used modified trolling motors on our electric only lake.
They use mechanical relays for power and reversing (3 required) I have had
several harrowing moments when I have tried to shut down or reverse and the
relays fused in the on position.

A speed controller may fail off, but I doubt it will fail to full
throttle...

Just food for thought...

Joe M

[Non-text portions of this message have been removed]

__._,_.___
Recent Activity
Visit Your Group
Give Back

Yahoo! for Good

Get inspired

by a good cause.

Y! Toolbar

Get it Free!

easy 1-click access

to your groups.

Yahoo! Groups

Start a group

in 3 easy steps.

Connect with others.

.

__,_._,___

No comments:

Post a Comment