phoenix70
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| posted on 30/9/08 at 08:19 PM |
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JAW enclosure
Hi Guys,
Has anyone found a suitable box to fit the JAW electronics or the display. Just about to go hunting, but thought I'd see if anyone had already
found one.
Ta
Scott
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adithorp
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| posted on 30/9/08 at 08:28 PM |
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I was going to have a look in Maplins for one.
I was wondering what to do about the heat sink. It being enclosed can't be good, can it?
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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big_wasa
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| posted on 30/9/08 at 08:41 PM |
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I am still looking. 
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Lars
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| posted on 30/9/08 at 08:44 PM |
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I have a small black project box from maplins.
I cut two holes on opposite sides of the heat sink and fitted a small fan on one and a finger guard on the other.
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RichardK
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| posted on 30/9/08 at 08:46 PM |
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I got mine from Maplins
Loads more pictures in my gallery (link below) and I did a pick list of everything I bought on the jaw website
LINKY
P.S If you get an ali box don't ground the box and ground the heatsink! Don't ask how I know!!
Cheers
Rich
Gallery updated 11/01/2011
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David Jenkins
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| posted on 30/9/08 at 09:22 PM |
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I used a Maplin box, with a 12v - 14v Maplin fan sucking air past the regulators. Unfortunately I don't know the Maplin codes, but the fan
should be easy to find.
When I turn it on with the engine off the air coming out is warm-ish. When the engine's running the air coming out is stone cold.
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martyn_16v
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| posted on 1/10/08 at 08:31 AM |
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Wouldn't it be better to fit mica insulators to whatever is attached to the heatsink to electrically isolate it? It sounds like a pretty poor
design flaw to have the heatsink 'live'
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MikeRJ
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| posted on 1/10/08 at 11:22 AM |
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quote:
Originally posted by martyn_16v
Wouldn't it be better to fit mica insulators to whatever is attached to the heatsink to electrically isolate it? It sounds like a pretty poor
design flaw to have the heatsink 'live'
In terms of JAW design flaws that one ranks pretty close to the bottom of the pile. Having reverse engineered the schematic, I just I hope the
designer knows a little more about software than circuit and PCB design.
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David Jenkins
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| posted on 1/10/08 at 11:28 AM |
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Funny you should mention that... never get into a situation where you have to unsolder a component - it is very likely that the pad(s) will lift off
the board. The PCB tracks are far too thin, and the pads are unnecessarily small for most components (although there's little choice around
ICs, the rest of the board could have been a lot more 'generous' ).
I use 2 products in my car that have been supplied by what could be called 'small enterprises' - Megajolt and JAW. The 2 are chalk and
cheese, as far as I'm concerned: The MJ PCB is well designed and made, and the product works well without much trouble - the JAW is flakey,
frail and generally looks like it was designed by an amateur. This is only a limited whinge though, as the JAW is cheap, and it did what I required
when setting up my bike carbs. I can live with the shortcomings as it isn't a permanent fixture on my car.
[Edited on 1/10/08 by David Jenkins]
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Lars
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| posted on 1/10/08 at 03:34 PM |
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If anyone needs a small fan and finger guard for their box I have a spare 50mmx50mm fan and 60mm finger guard (from Maplins item numbers JU23 and
RG07H).
They are new and still with original packaging. (did not return it to Maplins quick enough)
£5 posted
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adithorp
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| posted on 3/10/08 at 01:30 PM |
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I've just got a box from Maplins. Its part number N59FK, multi purpose ABS box.
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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phoenix70
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| posted on 14/10/08 at 07:57 PM |
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I've now finished my JAW enclosure, just thought I'd post a few pics.
 
JAW Enclosure 1
 
JAW Enclosure 2
 
JAW Enclosure 3
 
JAW Enclosure 4
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MikeRJ
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| posted on 14/10/08 at 11:51 PM |
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You've got a few holes for the air to get in, but how does it get out?
To be honest you'd be better off putting the LM317T on short leads and bolting it to the case with a mica or silicon pad and top hat washer to
isolate it.
If people are using the LED display then the 7805 should also have a heatsink on it. It gets very hot without one and will cause the voltage will
drift somewhat. Since the designer decided to use this as a voltage reference this will affect the accuracy of the unit.
I have soldered numerous ceramic decoupling caps to the power rails in order to reduce the amount of noise which otherwise is horrendous, since the
designer apparently decided to leave them out of the design. This has helped to stabilise the output, though it still jumps around a fair bit due to
the completely inadequate PCB design and poor choice of components. If anyone has a scope handy, check the "reference" voltage on
terminal "5-Yllw", a 2.5v reference that has +-2v noise on it....
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