Rugged, engine bay mounting

Oliver Sedlacek · Post by **Oliver Sedlacek** » Fri Dec 07, 2007 1:40 pm

As someone who has installed his Megajolt in the engine bay, I've always been a bit concerned by it's ruggedness. I've therefore made my own PCB with automotive rated components, and no sockets. I've added a couple of photos at http://rides.webshots.com/album/187745001srPbmU

MartinM · Post by **MartinM** » Fri Dec 07, 2007 2:46 pm

Very interesting!

Is that a SMPS chip on the bottom left?

And what's happening in the centre with regard the SM chip on top of the DIL position? Can you fit either?

Oliver Sedlacek · Post by **Oliver Sedlacek** » Fri Dec 07, 2007 3:58 pm

It's not an SMPS, it's a Nat Semi auto grade linear regulator. It's great because it is reverse polarity protected (and I checked it), and 28V tolerant. The board can take either a through hole DIL processor or an SMT processor, which is just as well as the DIL version is obsolete.

MartinM · Post by **MartinM** » Fri Dec 07, 2007 5:21 pm

Care to share the part number? ...

Oliver Sedlacek · Post by **Oliver Sedlacek** » Fri Dec 07, 2007 6:43 pm

It's the LM2941S. I've added the whole schematic to the webshots album.

Post by **brentp** » Fri Dec 07, 2007 7:27 pm

Very interesting! We have been leaning towards surface mount on the discrete components- we feel the 1206 package balances hobby-friendly DIY with size and ruggedness.

The LM2941S is interesting too, it looks like it might reduce part count in the power supply section.

Thanks again,

Oliver Sedlacek · Post by **Oliver Sedlacek** » Sat Dec 08, 2007 10:42 am

I think that with a bit of practice, anyone can solder 1206 as reliably as through hole. 0805 isn't too bad if you keep your hand in, and I've been doing a lot of 0603 recently, but that's best done with a steady hand and a magnifier. When hand soldering it helps to have pads that are perhaps a bit bigger than necessary, as it lets you heat the pad and the component at the same time.