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Wiring FET's to the AUX "output" in ESC's


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dyrodium
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Joined: 24 Aug 2004
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Wiring FET's to the AUX "output" in ESC's

*Grrrrrrr* edited

Last edited by dyrodium on Sat Aug 05, 2006 6:30 pm; edited 3 times in total

Post Mon Jul 31, 2006 9:29 pm 
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Glen
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you could always just run some wires off the fet on the board onto the bigger power fet. iirc most controllers just run fets in parrallel dont they? and if that doesnt work just desolder the original
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Post Mon Jul 31, 2006 9:32 pm 
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Spockie-Tech
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What model Scorprion is it ? I just had a look at the RobotPower pics, and I see at least one of them uses an "IPS" Fet (Intelligent Power Switch) for the Aux.

Thats basically a Fet with current and temp protection built in. If you replace (or augment) that with a standard Fet, you will lose the protection feature (if its that controller)

If it is that model, then you should be safe against blow-ups caused by the motor being a bit overpowered, it will just limit the spin-up time a bit as the controller current limits.

Adding another fet in parallel is easy, but you have to include a small resistor to stop the gate's from "ringing", and if it is PWM'ing fast, then you might need a charge-dump-diode as well to keep the turn-off fast.

The hard bit is making the additional fet mechanically useable with a bit of circuit board, heatsinks, terminal blocks etc, since soldering directly to the pins isnt very reliable.
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Post Mon Jul 31, 2006 9:48 pm 
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dyrodium
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Joined: 24 Aug 2004
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Location: Sydney


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It's the scorpion HX.
It seems grossly underpowered at the moment anyway, it has trouble running a p9004 at 12v. And that can't be anywhere near 12A Confused
EDIT: I've seen these on ebay: http://cgi.ebay.com.au/Spider-v2-1-FET-Turbo-for-Mini-Z-iWaver-XMods-EVO_W0QQitemZ190012805574QQihZ009QQcategoryZ34063QQrdZ1QQcmdZViewItem
Basicaly that's what you mean, only made for this not mini Z's Smile?
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Post Mon Jul 31, 2006 9:55 pm 
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dyrodium
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Ok, I got an email back from the robot power guys.

"Ok there are a couple of thinks to help with this.

1) Make sure you are running at 100% on. This will reduce heating in
the MOSFET to a minimum. To do this increase the travel on the AUX
channel on the radio until it cuts out then back off a bit.

2) You can double up the MOSFET by soldering a second one on top of the
first. This is a little crude but it will work.

3) You can replace the one on there with an external one. The IPS0151S
has been used. You can buy these from www.digikey.com They have the
same connections but are in a larger package that you can bolt to a
heat
sink."


Cool! Very Happy
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Post Tue Aug 01, 2006 8:29 am 
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