EggTimer Quark question

I have just finished assembling the Quark. I have a new respect for Mr. McGrath... But I digress. I am testing it with a vacuum chamber that sims to about 8,000'. The power-up checks all seem fine. I used LEDs to simulate the e-matches. They glow ever-so-faintly during POST and climbing. At apogee the drogue LED lights brightly. At 500' the main LED goes from glowing to off for about a 3/4 second then back to glowing. I would expect the main to glow brightly as the apogee circuit did. What have I done incorrectly?

Much thanks!

My guess is you have a cold solder joint on one of the resistors. Have similar problem on eggfinder TRS except it's with the drogue instead of the main. Cris confirmed it for me & I did same test with Christmas lights.

If you use LEDs for testing they WILL glow a little when "off" because there's a little under 1 mA of current going through them for the continuity check. As far as the channel that won't "fire", I'd check the optoisolator first... it's easy to get an incomplete solder joint with those stubby "J" leads.

I just started soldering mine..my first project solo-ing (thanks CaveDuck and WarnerR and ConMan) - but Im too emarassed to post pics ,I'm really butchering it so far.

Kenny

cerving said:

If you use LEDs for testing they WILL glow a little when "off" because there's a little under 1 mA of current going through them for the continuity check. As far as the channel that won't "fire", I'd check the optoisolator first... it's easy to get an incomplete solder joint with those stubby "J" leads.

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So I'd get the continuity glow on the main but no "fire" if the optoisolator had a bad connection? I'll check there. Much thanks again! The continuity but no fire had me stumped. Pretty easy to do really, have me stumped.

Has anyone put together a schematic for the Quark that they could share? That might be cool! Then again it might just give me a brain-cramp...

jrkennnedy2 said:

So I'd get the continuity glow on the main but no "fire" if the optoisolator had a bad connection? I'll check there. Much thanks again! The continuity but no fire had me stumped. Pretty easy to do really, have me stumped.

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Well, assuming that the optoisolator is OK I'd be looking at the row of resistors OR one of the solder joints on the processor. Putting the transistor in backwards will do it too... don't ask how I know.

:lol:

Glad its not snakes! I'd been bit...

Hi Conner. If I've read the thread correctly, I think the OP said he assembled this one himself. No need to beat yourself up

Yeah, Connor. Not your fault 😀

"Casually deletes post"..... Sorry about that. Well if you ever need any help let me know.

jrkennnedy2 said:

View attachment 270748

:lol:

Glad its not snakes! I'd been bit...

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Holee molee!!! Get out the desoldering braid Batman!!!:roll::bangpan::lol:

Ummmm, BTW, does it work now? :wink: Kurt :wink:

This one is ALL ME. Connor does GREAT stuff. Me, well thats another story. I have cleaned the bridge and will test this evening.

No joy. Main still does not fire as before. Back to looking for some other error...

jrkennnedy2 said:

Connor does GREAT stuff.

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Not always.

Any schematics available? I seem to be fascinated by the micro-current of continuity and then the drop of that during the time when the main should fire. That suggests a seperate circuit for the continuity which gets interrupted during the fire event? Very interesting regardless. Love puzzles and I have one on my hands now. I have 2 builds, LOC Bruiser and RW AGM-58 that are wondering where I went...

Hope this note finds you having a good day!

Did you test the pressure sensor output with a data cable? You might want to look at the two 4.7K resistors next to the pressure sensor...

timbucktoo said:

Not always.

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1/100 pretty good. PM me and I'll send you a brand new fully equipped TRS free of charge. Hopefully then you will see I will do whatever I can to make my customers happy...

jrkennnedy2 said:

No joy. Main still does not fire as before. Back to looking for some other error...

Click to expand...

If I can do anything for you let me know. I dont charge people to take a look at things that are already assembled.

timbucktoo said:

Not always.

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Give him a break! He made one poor quality unit in the over 100 he's done. He's going above and beyond trying to make you happy and here you are going around trying to convince people he messes up and does terrible work. That's stupid. He's a 16 year old kid trying to have a life. He's owning up to his mistake and wants to fix it. What else do you want form him? Let it go and stop acting immature. Seeing your posts on every eggtimer thread is getting really old.

cerving said:

Did you test the pressure sensor output with a data cable? You might want to look at the two 4.7K resistors next to the pressure sensor...

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I havent made/bought a data cable yet. However, I do see some activity the continuity current stopping for a brief time and restarting near loss of vacuum (simulating near ground level) . I will measure the 4.7s. This is quite fun, BTW!

Both 4.7K ohm read at about 28 oms on the board. That could be fine because without a schematic I do not know what circuits are behind the solder joints on those 4.7s.

jrkennnedy2 said:

Both 4.7K ohm read at about 28 oms on the board. That could be fine because without a schematic I do not know what circuits are behind the solder joints on those 4.7s.

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They should measure about 4.7K in-circuit too... they're pull-up resistors for the I2C lines. Sounds like you got a solder bridge somewhere... check the resistors and the processor.

Will do. Much thanks for the help and patience!