MS3 V3.0 Q9, Q12 ????

[onig]

Assembling my MS3 V3.0 board with Xpander.

1) Q9, and Q12 are supposed to have mica insulation under them. I don't see it, they look the same as the other components that get bolted to the metal heat sink strip. Can I put a pop-sicle stick or a piece of plastic under it to prevent them from touching the heat sink?

2) Thermal grease, would this be the same as dielectric grease or should I use something else?

3) I soldered the 40 pin socket onto the board. I want to do the same and solder a socket for U3, U4, U6, U7. Can someone give me the specs for the socket so I can source one locally to me?

4) BIP373, I can't even find it on the board. This BIP373 looks like a resistor, where am I to put the mica insulation, page 203 says it is required? I can't find the spot on the board for TIP125 and TIP122.

[CSXRT4]

Post a pic of your q9/q12. Are they metal backed or all plastic?

[billr]

Well, do not use a popsicle stick for an insulator! Not only is wood a good heat insulator, but those sticks are a lot thicker than you want/need for any kind of insulator there. A thin (in the .005" range) piece of plastic of the right type, like mylar tape, could work but you will need some thermal grease/compound on both sides; same as using a mica insulator. Thermal grease generally has some fillers in it to aid heat conduction, dielectric grease may not. Take the time to get some mounting kits with insulators, shoulder-washers for screws, and thermal compound; it will head off future problems. Are you not building this from a kit that included that stuff?

[DaveEFI]

If the device needs to be insulated from the heatsink, buy the correct mounting kit. In this case, for TO220. And while you're at it the correct thermal transfer compound.

[jsmcortina]

To the original poster - is this a kit or have you bought the bare board or what?

Any decent kit will include the mounting insulators for those transistors and a small tube of heat transfer grease.

James

[onig]

Yes, I bought the kit from DIY Autotune.
I don't know what mica looks like, never heard of it before.
But upon closer inspection I actually do have the mica insulation. It is clear and I could not even see it in the bag. The thermal compound is there as well.
My fault, sorry.

What about questions 3 & 4, any help there.

Please pardon my ignorance, I have never worked with semi-conductors before and this is a new language to me. But I am learning a bit, and that is why I bought the DIY kit.

Thanks for all your help so far, I really appreciate it.

[jsmcortina]

The BIP373 is in a bag labelled
(1) Q16
Bosch BIP373 12a IGBT
BIP373

Yes you can buy sockets if you want to. Turned pin type are the higher quality. They are regular "DIL" chips.

James

[onig]

Here is Q9, Q12, steel backed.



Here is the DIP373 that I was talking about, it looks like a resistor. Did I miss putting this in??



AND yes I do have a bag labeled Q16 that does not look like a resistor.

Here is my board so far.

[CSXRT4]

Ok your q9/q12 are good, just put the mica under them and use the plastic washer (manual shows how to screw these on). The bip373 is q16 and the resistor goes with that, if you are using the xpander spark outputs then you don't need to install these.

[billr]

Agreed, that 330 ohm resistor packaged as "BIP373" is odd (and confusing). Where is that supposed to go?

[jsmcortina]

Agreed, that 330 ohm resistor packaged as "BIP373" is odd (and confusing). Where is that supposed to go?

Between the processor and the BIP373 !
http://www.msextra.com/doc/pdf/html/MS2 ... e-3.3.html

James

[billr]

That's an MS1 or 2 requirement, already "built-in" to the MS3 daughter board?

[jsmcortina]

That's an MS1 or 2 requirement, already "built-in" to the MS3 daughter board?

Nope.

James

[billr]

Okay, I found that mod in the MS3/V3.0 manual ("- Connect a 330R 1/4W resistor between IGBTin and the top of R26."). I sure don't recall doing that when I built mine, but must have, since I have used that internal coil driver (DB37 pin 36) occasionally...

[dontz125]

The original kits had a VB921 for Q16, with no gate resistor - you jumped straight from JS10 (or whichever processor pin) to Igbt In. With a BIP373, you need a 330R base resistor, which you insert between Igbt In and JS10. The resistor labelled as 'BIP373' is that base resistor. Obviously, it could be labelled a little more clearly ...