Testing Voltages During Assembly - Need A Little Help.

squirrelgripper · Post by **squirrelgripper** » Sat Aug 07, 2004 8:16 am

I am at the point in the assembly where I am testing voltages.

1. With a 9 volt battery, I am getting 5.8V - 6V for each of the tests.
2. With a 12 volt car battery, I am seeing 10V for each of the tests.

Is this correct?

Thanks,
Iain, Little Rock, AR

Post by **brentp** » Sat Aug 07, 2004 3:31 pm

No- it should be a solid 5v no matter what the input voltage is.

Check the orientation of all the components so far, check for bad/cold solder joints and solder bridges. Don't proceed until you have it resolved!

Vorpal · Post by **Vorpal** » Sat Sep 10, 2005 4:57 pm

I'm through building the power supply part of the board. In the places I'm supposed to have +5v, I'm getting +4.88v. In the place where I'm supposed to see +12v, I'm getting +10.94v. I'm not really an electronics guy, but it sounds like there's no such thing as "close enough." Looks like I need to check my soldering, right? Or is this just a case of equipment (in)accuracy? I'm using a $50 multimeter from Autozone.

-Winston

P.S. I'm using a 12v hobby battery that's about 10 years old and tests out at +11.6v give or take.

1986 Toyota MR2 getting a Silvertop 4AGE 20v swap

Oliver Sedlacek · Post by **Oliver Sedlacek** » Sat Sep 10, 2005 6:22 pm

The 5V supply is generated by an LM2937 regulator, which is a good regulator but still only guarantees to produce an output in the range 4.75V to 5.25V. The processor is guaranteed to work over this range, so 4.88V is fine.

Vorpal · Post by **Vorpal** » Sat Sep 10, 2005 11:10 pm

Thanks, Oliver. Tolerances, I understand. I'm an engineer, just not a EE. Good to know that "pretty close" also counts in the electronics world sometimes.

It's also good to know that I've built the board correctly up to this point! This is my first real soldering project, and I must say I'm enjoying it. There's just something about smoking rosin that makes me feel like a mad scientist

1986 Toyota MR2 getting a Silvertop 4AGE 20v

Oliver Sedlacek · Post by **Oliver Sedlacek** » Sun Sep 11, 2005 3:01 pm

Tolerances are the differences between engineering and craftsmanship

Post by **brentp** » Sun Sep 11, 2005 4:56 pm

Good it's working so far. When soldering, the biggest concern is cold solder joints and accidental solder bridges.

In the instructions I should provide a link or info on basic soldering skills.

Looking for feedback on the new instructions, too- I'd like to see what areas I can improve.

Brent

Vorpal · Post by **Vorpal** » Sun Sep 11, 2005 6:35 pm

Brent,

I only have two feedback-related items:

1. The TPS option picture is missing from the instructions... not a big deal if you've paid attention throughout the rest of the instructions. Or perhaps you don't have a pic of this?

2. The board is just a hair wider than the aluminum case. I've tried every slot and it's the sam all around. Should I bend the sides of the case a little, or sand the edge of the board down? It seems like there is enough slop (wide tolerences

in the case fitment that bending the sides shouldn't cause a problem. What do you think?

-Winston

1986 Toyota MR2 getting a Silvertop 4AGE 20v

Vorpal · Post by **Vorpal** » Thu Sep 15, 2005 1:29 am

I solved the board fitment problem with good ole sandpaper... fits like a glove now. See a (blurry) pic here:

http://www.mr2oc.com/showthread.php?p=1 ... ost1342547

-Winston

1986 Toyota MR2 getting a Silvertop 4AGE 20v

Autosport Labs

Testing Voltages During Assembly - Need A Little Help.

Testing Voltages During Assembly - Need A Little Help.

No- it should be a solid 5v n

So my voltages are too low, too?

Tolerances matter

Thanks!

Craftsmanship

Good it's working so far.

Brent,I only have two

Problem fixed!