Voltage across IC1

Phaeton · Post by **Phaeton** » Sat Mar 31, 2007 3:12 pm

My kit arrived the other day & I've started to put it together, never done any electronics at all before. Soldered the first few items as per the HowTo & then have checked the voltages. I am using an AT PC power supply which is putting out 11.69 volts, all the 5.0V are correct but across IC1 it says you should have either 12V or the input voltage (assumes means 9V if using a battery) I am only getting 11.13V which is over 0.5V down is something wrong? Do I need to recheck all joints or can I proceed.

Cheers

Alan..

Post by **brentp** » Sat Mar 31, 2007 3:23 pm

That is no problem, as the power supply voltage is dropped a bit due to the diode in the MJLJ power supply.

Phaeton · Post by **Phaeton** » Sat Mar 31, 2007 3:51 pm

Thanks I will continue with the adventure

Alan...

Post by **brentp** » Sat Mar 31, 2007 4:01 pm

Good! I updated the instructions to say "Close to supply voltage".

Be sure you're not using too much heat and that you're using a soldering iron appropriate for electronics.. Hmm- should update the build guide with that info as well.

Phaeton · Post by **Phaeton** » Sat Mar 31, 2007 9:08 pm

Using a 30W iron is that suitable sorry if it's a dumb question but as I say this is all new & quite exciting to me, especailly if it all works. Done the next section & tested voltages, all the same so tomorrow I will install the active components (MAP).

Just got to sort out a pully, it's going on an A-series engine in UK, quite an expense item over here.

Alan...

Post by **brentp** » Sat Mar 31, 2007 9:15 pm

30W is fine. Here's one of many soldering tutorials out on the interweb:
http://www.geocities.com/ammarini/soldar1.htm

Phaeton · Post by **Phaeton** » Sat Mar 31, 2007 9:19 pm

Brent do you live on t'interweb LOL

Alan..
p.s. Thanks

Post by **brentp** » Sat Mar 31, 2007 9:28 pm

No, I'm actually in the garage trying to remove the rear subframe of my E36 M3 to install new bushings with 100K miles of road dirt falling on my head..

And I just found out that I need my axles rebuilt.

Grrrr!

Phaeton · Post by **Phaeton** » Sun Apr 01, 2007 5:55 pm

Build complete, NO SMOKE!!

Last question on this bit, I'm sure many many more to come

Once complete voltage across IC1 is now down to 10.81V is this acceptable & am I worrying too much

Alan...
O/T hope the rest of the rear axle stripdown went okay.

Post by **brentp** » Sun Apr 01, 2007 6:27 pm

That should be ok. The important bits are the 5V across all of the active components. I think you're doing well so far.

So you're installing a new ignition system *and* stepping into the world of electronics. cool!

Brent

--I had to put a 6 foot piece of pipe on breaker bar for the axle nut! One axle came out, and the other is still frozen in the hub. Hopefully the penetrating oil I soaked it in last night will unstick it.

Phaeton · Post by **Phaeton** » Sun Apr 01, 2007 8:34 pm

Thanks again Brent for the hand holding, all the 5V's were spot on, just got to work out what to do next LOL

Alan...

TwoSheds · Post by **TwoSheds** » Fri Feb 08, 2008 5:41 am

Sorry to resurrect this, but I have finally started assembly of my Megajolt Lite Jr (I use it's full name out of respect

) and was trawling for the answer as to why I had the 0.5v drop mentioned here (12.3 to 11.8 on a motorcycle battery in my case) and I just thought I'd point out that the instructions still say "Verify +12v (or whatever your supply voltage is)." - did you amend them somewhere else? (Higher up this topic you said "Good! I updated the instructions to say "Close to supply voltage"")

I am also stepping into the brave new world of electronics for the first time, and am enjoying it immensely - but I think that this is mainly due to the clear instructions, the clearly labeled packaging and the quality if the PCB. (see I'm getting into the jargon already)

Thanks Brent! Great piece of kit

p.s:

brentp wrote: --I had to put a 6 foot piece of pipe on breaker bar for the axle nut! One axle came out, and the other is still frozen in the hub. Hopefully the penetrating oil I soaked it in last night will unstick it.

I do hope it wasn't a left-hand thread

TwoSheds

Post by **brentp** » Fri Feb 08, 2008 4:36 pm

Thanks! I glad for many the benefits for the MJLJ are multi-faceted.

As I've said before, I've learned a lot in the process as well. I trust it will show in our upcoming projects!

At the time I was really regretting digging so deep into the M3's suspension, just to replace some sub frame bushings. Now that it's done and time has passed, I'm just blown away at how GOOD it handles. It's truly an amazing machine.

However I think I forgot to stake the rear axle nuts... I should fix that soon.