ZipZap Monster MOSFET Mod (Work in progress......)

ph2t · Post by **ph2t** » Sat Nov 13, 2004 10:55 pm

getting impatient, hopefully will have my zz monster here this week!

does anyone know if it's been done yet?

cheers,

ph2t.

crazydave · Post by **crazydave** » Sun Nov 14, 2004 6:37 am

I've got a package in the apartment office, and I'm hoping and praying it's my FETs.

Here, while I'm waiting for the apartment office to open, maybe I can get some pics of the PCB for ya.

I think it's gonna be pretty easy.

Hold on, I'll be back.

ph2t · Post by **ph2t** » Sun Nov 14, 2004 6:55 am

cool man. take some pics of both sides of the PCB is ya can.

cheers,

ph2t.

chrome · Post by **chrome** » Sun Nov 14, 2004 11:31 am

Note that because of the drivers (labeled D9D) the transistors cannot be directly replaced with FETs without adding a few jumpers to drive them correctly. Basicly you have to remove the D9D parts and wire it up like the ZZSE h-bridge.

codeSuidae posted this over at Wegotu. Thought it might help if you guys hadn't seen it.

Later,
Chrome...

PS. Not sure if I'd want FET's in mine until someone comes up with a way to give it more suspension. It's almost got TOO much power as it is.

crazydave · Post by **crazydave** » Sun Nov 14, 2004 11:56 am

Sorry I didn't get my stuff up yet, my camera's battery was dead and I'm waiting for it to charge, but, yeah that's it, it was an easy one to figure.

I agree with you chrome, but I think a propo throttle might help as much if not more than suspension, either way I wanna run the fastest motor and gears with power to spare. I gotta, I just gotta.

My apartment's office don't open 'til noon today. One more hour to go.

I really hope those are my FETs up there, I'm getting impatient. If it's not I think I'm gonna go rob FEts from one of my other cars.

chrome · Post by **chrome** » Sun Nov 14, 2004 2:30 pm

What if we stole a board out of one of those panther clones? Those got propo throttle right? Even thought they use magnetic steering, couldn't you just hook the motor up to the positive and negative leads from the magnetic steering?

Later,
Chrome...

betty.k · Post by **betty.k** » Sun Nov 14, 2004 3:19 pm

you'll have to add an h bridge to the steering if you wanna run a mt with a bit style pcb.

crazydave · Post by **crazydave** » Sun Nov 14, 2004 5:21 pm

Here's the PCB pics. I love my new camera. You can actually see the marking on the trannies better in the pics than in real life.

Having a problem with the FETs. The ones marked D9D swap right out for the N-Channels no problem. Going by the base, the S1As seem to be N-channel, and the S2As seem to be P-channel, but when I put a FET in their position the car just dies.

What could be causing that, and how can I determine fer sure the polarity of the trannies?

ph2t · Post by **ph2t** » Sun Nov 14, 2004 6:50 pm

dude, betty just scored his zz mt, I'm gonna take some readings and let you know asap!

ph2t.

codesuidae · Post by **codesuidae** » Sun Nov 14, 2004 9:09 pm

You might want to read my original post,

I wrote this up on one of the boards already, but I can't seem to find it again. Too many seperate boards for me to recall where I put the detailed instructions.

The D9D's will have to be removed. As you can see, they work by drawing current from the p-channel device gate and feeding it to the n-channel device gate. Obviously this won't work with FET's. You will have to remove those completely and reconfigure the h-bridge to look basicly like the ZZSE h-bridge.

I have detailed instructions about how to do the mod if required. (actually, I have the notes I took when I did mine, which I'll transcribe into a format that will make sense outside my own mindscape). From memory, the gist of it is that you remove Q11 and Q12, connect R21 to Q7 and Q6, then connect ??(Edit, I've labeled this one as 'R9' in the diagram, that is not the same as the R9 on the board! I don't know what the correct name is, my PCB is too blurry to read many component names) to Q5 and Q8.

I have a 900x600 2-layer photoshop document with top and bottom images of the PCB, with the bottom mirror imaged so all the via's line up, makes it easy to trace things. You can click back and forth between layers to switch sides of the board. I reversed the text on the mirrored side of the board so its easier to read. If the link above doesn't work, I can email it. Its nearly 4Mb, and my webhost only provides 10Mb of space, so I linked it directly off my computer.

crazydave · Post by **crazydave** » Sun Nov 14, 2004 11:34 pm

Thanks a bunch codesuidae, you're a saviour.

Just one question though. Your directions made enough sense, it's just that PCBs make my head spin, and I'll never figure out exactly where to put those jumpers. Which end of the resistor do I come off of, and which pin of the FET do I connect it to?

Sorry for the extra questions, I really should learn to figure out this stuff myself, but it makes my head hurt.

codesuidae · Post by **codesuidae** » Mon Nov 15, 2004 1:28 am

Anticipating the need, I've taken a number of photographs. I'm working on a web page with details.

codesuidae · Post by **codesuidae** » Mon Nov 15, 2004 4:04 am

codesuidae wrote:Anticipating the need, I've taken a number of photographs. I'm working on a web page with details.

This is preliminary documentation. Note that there are questions that need clarification in the text, and the writeup needs work to clarify exactly what the steps are.

ZZMT Preliminary FETMod info

Please provide corrections if you have them. Also, if the slikscreen printing on your MT is more clear, verify or correct my component names.

ph2t · Post by **ph2t** » Mon Nov 15, 2004 4:14 am

Holy shit batman!

Damn there's a lot of work involved!

What is the performance increase like? Is the margin of increase as great (relatively speaking of course) as the original bit's and nonSE zipzaps?

well done again mate!

ph2t.

crazydave · Post by **crazydave** » Mon Nov 15, 2004 8:14 am

ph2t wrote:Holy shit batman!

Damn there's a lot of work involved!

Ummm, yeah, and here ol' simple minded dave thought it would be a direct swap. I suck.

Thanks again codesuidae, that's great, you do very thorough work.

I'll go over that, and try to get it working in my car later today.

bitPimps.lixlink.com

ZipZap Monster MOSFET Mod (Work in progress......)

ZipZap Monster MOSFET Mod (Work in progress......)

Re: anyone mosfet modded the zz monster truck yet?