I've got FETs in my SE!

Son_Gokou · Post by **Son_Gokou** » Sat May 15, 2004 3:55 pm

BTW, found another site with some good FET modding info. This basically eliminates the resistance of some resistors, and does the bypass mod to the FET like cyborgzero told us to do.....

http://members.cox.net/codesuidae/FetMod.html

I'm thinking of doing this FET mod to my SE....micro_amps, c'mon dude, why won't you just share your method with us? Your goal is to do the FET mod for people who have no electronics experience, but for those of us who want to give it a try, just spill it bro!

crazydave · Post by **crazydave** » Sat May 15, 2004 5:53 pm

Hey thanks for keeping us updated.

I read it over, and I'll tell you what this adds to what we already got.

There are four resistors that can be removed and jumperf to open up more current to the FET's gate. There are also 2 more than can be removed and replced with resistors of a higher value, for a slight increase in peformance, something the author didn't reccomend bothering to waste your time with.

I'm gonna try to remove and jumper those four restors, and see how it works. Cyborgzero's bypass mod has made my SE an enjoyable little car, so I can only imagine that any more improvement, no matter how slight can only be a good thing.

crazydave · Post by **crazydave** » Sat May 15, 2004 9:35 pm

Found a mistake in that link. I had to go back to make sure I wasn't losin' it, but here's the screen capture to prove it.

Notice it says RDB1 should be bridged. That is wrong. That is the one that cyborgzero had told us to remove when doing his bypass mod.

Bridgeing that one with the voltage bypass mod, will make your car run nonstop.

I bridged RDB2-4, and there is pretty decent gain in performance. So that info is good, thanks for sharing it.

Son_Gokou · Post by **Son_Gokou** » Tue May 18, 2004 2:10 pm

crazydave wrote:Found a mistake in that link. I had to go back to make sure I wasn't losin' it, but here's the screen capture to prove it.

Notice it says RDB1 should be bridged. That is wrong. That is the one that cyborgzero had told us to remove when doing his bypass mod.

Bridgeing that one with the voltage bypass mod, will make your car run nonstop.

I bridged RDB2-4, and there is pretty decent gain in performance. So that info is good, thanks for sharing it.

No trouble at all pimp...

Oh, BTW crazydave....have you tried adding an extra cell to the SE after the FET mod, and do you know exactly how many MPH that thing can go? I hear RCmart.com has a Tamiya 4WD speed checker if you look around in the Mini-Z section...here's a few links:

http://www.rcmart.com/catalog/product_i ... 66d3426a82

http://www.etamiya.com/catalog/product_ ... cts_id=892

When I get enough money, I plan to buy it...I'm adding it to my "list of things to buy when I have 1000+ dollars".

crazydave · Post by **crazydave** » Tue May 18, 2004 9:16 pm

Son_Gokou wrote:Oh, BTW crazydave....have you tried adding an extra cell to the SE after the FET mod, and do you know exactly how many MPH that thing can go? I hear RCmart.com has a Tamiya 4WD speed checker if you look around in the Mini-Z section...here's a few links:

Nah, you know, I'm not worried about stuff like exact MPH, I just wanna see my car go, and if it looks like it's going faster, then that's all I ever wanted.

I'm not worried about adding extra cells to the SE, because for technical driving on my track, it's already getting too fast for good control. It's already throwing it's weight around in the corners pretty good. Any more defeats the purpose of the SE to me. If you just want top speed with no handling you might as well stick with Bits.

payaso · Post by **payaso** » Tue May 18, 2004 9:23 pm

crazydave wrote:I'm not worried about adding extra cells to the SE, because for technical driving on my track, it's already getting too fast for good control. It's already throwing it's weight around in the corners pretty good. Any more defeats the purpose of the SE to me. If you just want top speed with no handling you might as well stick with Bits.

Well put Dave. I agree.

silla

Son_Gokou · Post by **Son_Gokou** » Thu May 27, 2004 7:42 pm

I think I realized something...

It says QD1 and QD3 should be jumpered. Well, I remember that QD3 originally had 2 trannies stacked, so that was why forward was faster than reverse...in an H-bridge, you need to take in one N channel and one P channel for negative and postive power (just an educated guess) I think that QD1 and QD3 control the forward voltage, because when you bypass the gate voltage from QD3 to QD1, the forward drive gets faster. This is just a theory....

To make the Forward drive faster, you could either stack FETs on just those 2 FETs...and, just a theory....to make reverse faster, you could perform the gate jumper on QD2 and QD4...

To back this up, I remember when I was driving my SE around, without the body or black clasp on....mistake, when the bottom of the kitchen refrigerator mashed off QD2. The reverse function was disabled, but the forward drive remained safe.

Just a theory....

91LudeSiT · Post by **91LudeSiT** » Thu Sep 02, 2004 12:24 pm

So where do I get somebody to install this mod for me?

I have no soldering skills on something as small as my SE. Also after this mod can i run a Li-po batt?

HACHI-RYOKU · Post by **HACHI-RYOKU** » Thu Oct 21, 2004 12:25 pm

If you use lipoly cells, I would recomend using the npn fets and the pnp fets. Performing the H-bridge with only npn fets doesn't seem to do it with the higher voltage and current. It would take too long to explain why. If nobody has contacted you, then PM me. I may be willing.

ph2t · Post by **ph2t** » Thu Oct 21, 2004 6:36 pm

Hachi, what's the performance boost like when running lipo? I'm thinking of getting this cell:

E-Tec HIGH-C Lithium-Polymer 80mAh Single Cell
http://www.aircraft-world.com/shopexd.asp?id=2674

cheers,

ph2t.

codesuidae · Post by **codesuidae** » Tue Oct 26, 2004 4:45 pm

crazydave wrote:Found a mistake in that link.
Notice it says RDB1 should be bridged. That is wrong. That is the one that cyborgzero had told us to remove when doing his bypass mod.

Bridgeing that one with the voltage bypass mod, will make your car run nonstop.

Good point, I forgot to note that RDB1 should be removed when setting up that jumper. Thanks.

(edit: In my defense, upon editing the page to note the requirement I see that I already had two seperate notes that RDB1 should be removed if the gate jumper mod was made. I've added two more, in the event than an inattentive reader should attempt the mods.)

crazydave wrote:I bridged RDB2-4, and there is pretty decent gain in performance. So that info is good, thanks for sharing it.

I'm glad you found it useful. If you see any other problems with the page lemme know and I'll correct them (I see a few misspellings already

)

ph2t · Post by **ph2t** » Tue Oct 26, 2004 5:40 pm

hey code, has the duty cycle improved on the new model se's? or are we still looking at only 60% (was it?) duty cycle for full throttle?

good to see ya still around

ph2t.

codesuidae · Post by **codesuidae** » Mon Nov 01, 2004 9:38 am

Howdy ph2t, I think the SE that I was testing was running around 30%. I looked for some screen shots of the scope to verify that, but it seems I've misplaced some of them. I've got one from the analog duty cycle mod, but I didn't write down any details about it, so I don't know under what conditions it was taken.

I bought a new SE this weekend, the Ford GT, date code 08A04, part no. 600-7050. I tested the board and it looks like its doing about a 50% duty cycle, and it does seem a bit spunkier than the older ones.

They've got Starsky&Hutch SE's on clearance cheap too, so I'm going to pick up one of those too.

ph2t · Post by **ph2t** » Mon Nov 22, 2004 7:33 pm

cool, good to know...

Also, ages ago I think the official schematics for the ZZ SE were floating around the net? Does anyone have them???

Cheers,

ph2t.

codesuidae · Post by **codesuidae** » Mon Nov 22, 2004 10:33 pm

ph2t wrote:Also, ages ago I think the official schematics for the ZZ SE were floating around the net? Does anyone have them???

You are probably thinking of the transmitter schematics published by the US FCC (ZZMT transmitter schematic is also available, unremarkably, its almost identical). If you have a transmitter with a US FCC ID number you can look the reports up on the FCC website, or you can find a direct link from this page.