upgraded FETs

[neurokinetik]

I'll try to post one later, but I guarantee it isn't going to help...

[danny_v_l]

hey neuro, this i kindda confusing and i don't want to cause u troble but, i under stand the diagrams but how do u conect it to the esc, or does it just go to the bats and mottor, heres what i'm trying to say, ok u have a nice stock xmod and u wanna do this mod so u build ur little chip with ur fets on it then attach it to the bats and motor along with the stock wires?

[neurokinetik]

This was the first revision, but the only difference is that there are now only four wires connected to the board instead of 7. You solder the wires directly to the board where the pins on the stock chips used to be located. It's not all that easy to do without a fine-tipped soldering iron and some practice. Still much easier than FET stacking though.


Here is a quick shot of bottom side of the board before the FETs are removed. (Actually, the FETS in this pic were swapped for a different part number, but they look the same.) The FETs are the two black rectangular chips in the upper left of the picture. In this pic, they say F7389 on them, the stock XMods will say A1792. Note that the same chips are used on the top side of the board to run the steering servo. See the little dot on the bottom left of each chip? That marks where pin 1 is. Pin 2 is the next one to the right, followed by pin 3, and Pin 4 is at the bottom right. The top side of the chip is pins 5-8, going right to left. Pins 5-8 are all the same connection on these chips. Look just above the right chip, and you can see that it is labeled IC5. The left chip is IC6.

[danny_v_l]

thanx

[danny_v_l]

hey i have a old burnt out rsx, can i take thosefets off abd stack them on my supra?

[SuPrBuGmAn]

neurokinetik - there is a user at XModRC thats using a similar FET setup on his Civic. He's using a voltage regulator to keep the board regulated to 5v while allowing as much power(well, to a point - 25v) as possible to the motor.

You can see some diagrams and info on the setup he's using here.

In your setup, are you still using a zener setup to regulate the board power or have you applied some sort of on/off Vreg to regulate your board as well?

I may attempt this mod, just trying to figure out the most optimal setup.

[neurokinetik]

Looks like he's saved me some work. I have two totally different projects going, one is using the FET mod, but the drag Civic is currently running on stock electronics. I was planning to merge the two projects and do some form of regulation down the road, but I hadn't gotten around to figuring out how I wanted to do it yet.

[neurokinetik]

Originally posted by danny_v_l
hey i have a old burnt out rsx, can i take thosefets off abd stack them on my supra?

Yes, you could.

[danny_v_l]

would i benifit from it, like power, accel?

[scatmanjohn01]

hey neuro with those fets that you upgraded to, whats the lowest number of turns possible on a mottor with put frying? also do you know the lowest number of a turns a motor can have with out frying a 3x2 stack of irf7389's? one more question... what on the esc board determines how much the voltage limit from batteries is? i mean like, how would you upgrade the board so it could run more than 8.4 (6 ic3) cells?

[SuPrBuGmAn]

IC3s put out 1.2v don't they? 6 IC3s put out 7.2v. It would take 7 IC3s to run at 8.4v.

Anyway, there is a guy on XModRC.com that will be running a 14.4v after upgrading the FETs and replacing the zener style regulation with an on/off voltage regulator(5v). He's going to be running (4) 3.6v Lithium Ion AAs to achieve the 14.4v incase anyone was curious.

[scatmanjohn01]

ic-3s are 1.45 v if im not mistaken. and yes i already read jshwaa's thread

[SuPrBuGmAn]

Originally posted by scatmanjohn01
ic-3s are 1.45 v if im not mistaken.

Maybe I'm mistaken? Who knows, if thats true I'm going to have to pic up some IC3s myself, the 15min recharge isn't enough for me to get them on its own..

[TypeZer0]

1.2 volts is their rating but all of the rechargeables i've seen so far puts out anywhere from 1.34 to 1.60 volts when fully charged. these energizer 750mah cells i got from walmart (bit less than 10 bucks for a package of four) are 1.6 volts when fully charged and maintains at least 1.3 when they're close to depletion. in fact, i had a hard time getting them to charge in my radioshack charger because the xmod battery charger has a voltage detector and if it's too low or too high it wont' charge and well, the energizers were too high lol. i'll probably look for the 30 minute energizer charger i saw somewhere

[Doctoraudio]

neurokinetik

Can you make me one of those fet boards ready to solder on?
Thanks!

Team Insane X-Mods