Shrink wrap on CF4 be careful!

[Hootini]

I had a distortion problem from a very loud CF4. The distortion was so bad that I think I blew my speaker, but not 100% sure. I accessed the pot by cutting away the shrink wrap (thanks to all you helpful members) to lower the volume. I noticed though that the pot was so sensitive sometimes it caused distortion and loss of volume. My guess is that the shrink wrap was causing pressure on the pot which caused the distortion intermittently. Now I leave the pot exposed. So far so good!

[Madcow]

Don't shrinkwrap a CF!!!

This comes from Erv... somewhere in the posts.

It will heat up too much and damage the components.

MC

[Barmic Rin]

I lightly bubble wrap around my CF1, but only lightly!!! Be advised, heatshrinking it is like leaving a baby in the bath on it's own, with just a plastic bag to play with!!!

The troopercoms the 501st use can be shrunk, but NEVER the CF!!!!

[Novastar]

Yup... try not to heatshrink cover CF. To some extent, you might be OK, but the entire concept to be aware of is that 1.5A is running around all in there in certain ways and at certain times. The heat needs to be able to escape. Much like the heatsink for the LED itself.

At the same time--well, if you're only setting CF to output 1A or 700mA... you might be ok. Not to mention if you only run it for a little while at a time (read: you turn CF on, glowing saber for 3-5 minutes... shut it off for a minute or so... do it again, etc.).

But yup--ultimately... don't completely mummify CF... just get it into a cradle to avoid shorts and so forth.

As it is--if the sides of the board touch the sink tube... you STILL aren't likely to witness a short--since that's just the SILICON touching, not so much the wires. Well... I hope. It depends on how you wired things up and how much you protected/shielded your solders! :)

[Strydur]

Hmm.. I am the one who heat shrinked his card. I dont see why Ervs board would need to burn off a bunch of heat though. Anyone find where he says not to?

[Clockwork]

I am pretty confident it was in response to the Spaghetti Monster. Although I can't recall exactly where he states it.

[xwingband]

I am pretty confident it was in response to the Spaghetti Monster. Although I can't recall exactly where he states it.

Correct. The tape mess had stopped the board from being able to burn off any heat and had desoldered stuff.

It's a minimal risk though. Say if the CF is 90% efficient even running a V at 1A would be a bit less than 1W of power making heat.

[Hootini]

Hmm.. I am the one who heat shrinked his card. I dont see why Ervs board would need to burn off a bunch of heat though. Anyone find where he says not to?

No fault of yours Tim. Just to clarify. My pot is so loose it could not have been the shrink wrap. Perhaps I fiddled with it a bit too much. Now I put some electrical tape around it, just to secure the pot. I also put some pink bubble wrap to secure the card. Thanks for all your help! I love this forum!

[CybKnight]

Just remember that anti static pink bubble wrap has an expiration date.
Its treated with a chemical to stay anti static, but this wears out after some months. A year from production at the max. After expiration, it is just as bad as normal bubble wrap, when it comes to static discharge.

Having any "normal" bubble wrap moving around close to sensitive electronics, might cause problem, as the static buildup can knock out certain components very easily. Problem might not show up strait away, but might show up as unstable behavior.

Just a word of caution.

[Hootini]

Just remember that anti static pink bubble wrap has an expiration date.
Its treated with a chemical to stay anti static, but this wears out after some months. A year from production at the max. After expiration, it is just as bad as normal bubble wrap, when it comes to static discharge.

Having any "normal" bubble wrap moving around close to sensitive electronics, might cause problem, as the static buildup can knock out certain components very easily. Problem might not show up strait away, but might show up as unstable behavior.

Just a word of caution.

Many thanks for info. Do you have an alternative solution for some card support?

[LordMasoch]

PVC sled?

[erv]

to strydur (and others) : my recomendations / reasons for not shrinking the boards are:

- heat, if you run it at 1.5A. It's close to the saturation current of the coil and that where it starts to heat up more than just a bit, compared to 1A
- no good to add any sort of pressure on the parts, they are all heating up, not talking about the mechanical stress (like on the potentiometer)
- you loose access to the wiring. If you really think you'll be able to make a saber and NEVER open it again to fix / change something, you can't imagine how wrong you are :rolleyes:

For electrical isolation, do what our friend MadCow is doing : use a bit of plastic film or mylar, cut a tape of CF length / 8 mm wide and glue it on the edges of the board, it will make sure the board or the connections / soldering don't touch the hilt.

Erv'