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FrozenGate by Avery

DIY Thermal LPM for under $50






I actually built one of these about 2 months ago, but I failed:(. I gave up because I am waiting for summer break so I can figure out what went wrong.

I used MarioMaster's and Jib's schematics but the readings seem to fluctuate a lot. It worked for a moment and I went eat dinner came back and it didn't work :undecided::confused:
Schematic:
LPMscm.jpg


Board:
LPMbrd.jpg


Actual board:
IMG_0110.jpg


Heatsink:
IMG_0109.jpg


Tec:
IMG_0101.jpg


Tec when I first got it:
IMG_0098.jpg
 
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Well, yes, I turned the pots but I couldn't get it to zero. it would jump from 0 to 7V to negative 5V and back down and up and everywhere LOL. The board was extremely hot and I didn't know and burned myself :mad:
 
WOW. That does not sound Right. It should not get hot at all.

First you are running the LCD screen/"if Using" on a separate battery correct.?

2. The Sensor Need to be plugged in, in order to calibrate it.

3. Turn the 5k pot to 0.

4. After you have it Zero put a laser that is 100mW or more that you know 110% sure its on point.

5. Then turn the 10K pot Left or Right to the mW of that known laser.

Then you are finished.

But your meter should not be getting Hot.
 
No, they are both bourns multiturn pots. Really expensive, about $4-$5 dollars for one trimmer pot.

Well, I didn't have one of those LCD voltmeters, so I used my DMM set to read volts. I kind of figured something was wrong when I noticed it got hot. Maybe something wrong with the schematic.

I messed with the pots so much I don't really know where they started. They just keep turning and turning never ending turning. :yabbem:

I haven't touched it since then. I keep it in a box next to my desk.

I'll be doing another try at this soon as finals are over. Order new boards and new parts and buy a LCD voltmeter.
 
You must of damaged something then.

Usually multi turn pots keep spinning but you can feel like s spring clicking if you go to far either way.

You can use your DMM to Find out were they are.

If i was you i would not jump the gun and order all new parts.

Just get a New IC. First. I beat that is what friend.

Find out where the pots are using your DMM and your set.

I can even send you a IC if you want. Just cover Shipping.:) Ive got plenty.;)

Iam in a Giving Mood Tonight.:crackup:
 
Also make sure your orientation of your Lm358 is correct.. I can't tell which side of the PCB your view is of.. But if you mess up and get it flipped.. Your applying VCC to the out1... and that would certainly make it unhappy and probably get hot.

Your DMM should work fine though. All your doing is reading a voltage. Nothing special is required to do that.
 
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Thanks! but I have extra LM358s but out of trimmer pots. I actually built 2 of these and both had the same problem. :(

I doubled checked every part to make sure they were oriented correctly, but somehow still didn't work out.

I just want to order new parts to start fresh on this again. I made a revision on my board, so hopefully it won't happen again.

EDIT:
Sorry, red is top layer and blue is bottom layer. There are some connections you can't see because they are connected to ground and you have to run the ratsnest to see it.
 
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Man your schematic and layout seem correct. Ive recently done a new layout of this circuit and it works great, if you want I can send you a spare board I have to test with:

 
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Gah, I am envious of these little boards. Anyone want to produce me one that I will buy for ~$15-$20? I could build one myself, but I would make a messy job of it, and it would be huge in the end anyway (I would end up using through-hole components, probably, for ease).
 
Sweet job jib!

I like those connector terminals you have there!

I'm planning on using new different parts for my LPM and you gave me ideas!
 
jib77 said:
Man your schematic and layout seem correct. Ive recently done a new layout of this circuit and it works great, if you want I can send you a spare board I have to test with:

Click to expand...

Nice professional looking PCB....:beer:


Jerry

You can contact us at any time on our Website: J.BAUER Electronics
 
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