Here it is... 6x blu-ray in kryton, finally done

Re: Here it is... 6x blu-ray in kryton, finally do

I used the rckstr driver. I think the batteries might have been drained below the blu-ray voltage threshold, since he says the driver takes 2.5v which is why I only came out with 120mA. The batts came off the charger at 4.3v (I measured AFTER the diode was dead... great idea.) They were probably only around 3.5v when I dialed it in. Oh well. I really did learn a lot from this build, so I'm not afraid to go for 6x blu-ray revision A lol....

Re: Here it is... 6x blu-ray in kryton, finally do

danq said:

A constant-current driver should be fairly independent of battery voltage, within certain upper and lower limits. I think something is wrong with your driver.

Click to expand...

He was dialing in the current with the driver out of regulation. I don't think it's the driver... Once it was regulating again, the current was simply set to 240mA, that's all.

Expensive mistake tho..

Re: Here it is... 6x blu-ray in kryton, finally do

Gus - my condolences on your loss.....However, I think it's awesome that you let us know what probably happened to kill it.

Hopefully your sacrifice will prevent future deaths!

Re: Here it is... 6x blu-ray in kryton, finally do

IgorT said:

[quote author=danq link=1210757469/0#14 date=1210925614]A constant-current driver should be fairly independent of battery voltage, within certain upper and lower limits. I think something is wrong with your driver.

Click to expand...

He was dialing in the current with the driver out of regulation. I don't think it's the driver... Once it was regulating again, the current was simply set to 240mA, that's all.

Expensive mistake tho..[/quote]
yes... I said "within certain upper and lower limits" - but failed to notice that he was outside those limits.

It's still not entirely clear to me... maybe I'm in a brainfog - were there were 2 batteries, both at 3.5V? That would be 7V total; minus the driver's 2.5V drop; giving 4.5V for the LD. Not enough probably, on the edge.

This is one reason a more sophisticated driver like DrLava's is a good thing, gives a bit more wiggle-room and protection. Shutdown at under-voltage would be great; an indicator LED might be easier to incorporate in other designs.

What about a tiny LED on the battery side that is set up so its V[sub]f[/sub] is reached only when the batteries are up to snuff? Then you'd know not to make a current adjustment unless the light is on. There are smt led's that draw very little current so would not add significantly to battery drain.

Re: Here it is... 6x blu-ray in kryton, finally do

IgorT said:

[quote author=danq link=1210757469/0#14 date=1210925614]A constant-current driver should be fairly independent of battery voltage, within certain upper and lower limits.  I think something is wrong with your driver.

Click to expand...

He was dialing in the current with the driver out of regulation. I don't think it's the driver... Once it was regulating again, the current was simply set to 240mA, that's all.

Expensive mistake tho..[/quote]

Bingo :-/

Oh well... new 6x is already on its way

Re: Here it is... 6x blu-ray in kryton, finally do

Gus, I highly respect your attitude. [smiley=thumbsup.gif] That would have pissed me off to no end, but maybe worth the lesson, I don't know. I just bought a rpl blue 30 so I won't be fooling with new laser equipment for a while now, but I plan on making a blu-ray burner next. Thanks for sharing your lesson with the rest of the class. Good to see you jump right back up. +1

Re: Here it is... 6x blu-ray in kryton, finally do

Thanks.

--hydro

Re: Here it is... 6x blu-ray in kryton, finally do

Gus -- At that power, It should not have failed.

Mike

Re: Here it is... 6x blu-ray in kryton, finally do

ok so let me get this right aboguht the rckstr drivers if im usign a br one and a 9v battery if the battery gets low on volts nad dies it coudl blow my laser?

Re: Here it is... 6x blu-ray in kryton, finally do

ah man. total bummer. well keep up with the good attitude. way to take one for the team.

Re: Here it is... 6x blu-ray in kryton, finally do

glona said:

ok so let me get this right aboguht the rckstr drivers if im usign a br one and a 9v battery if the battery gets low on volts nad dies it coudl blow my laser?

Click to expand...

NO! That can't happen....

Only if you were to adjust the current with the battery so low, that the driver could not regulate anymore, could you kill the diode.

When the batteries are almost empty, the driver drops out of regulation. If you then try to reach a certain higher current, you are actually setting the driver for a MUCH higher current, and when the batteries are full again, the current you actually set will blow the diode.

But the rckstr driver doesn't have a pot and comes pre set to a current, so you can't really mess anything up.

Re: Here it is... 6x blu-ray in kryton, finally do

Hemlock Mike said:

Gus -- At that power, It should not have failed.

Mike

Click to expand...

Are you saying, that your 6x Blue Ray doesn't die at 240mA, but puts out almost 150mW?

Re: Here it is... 6x blu-ray in kryton, finally do

OUCH __ WAtch out -----

I built this about 3 months ago and I think I'm running 130 mA NOT 240 mA.
I reviewed my data and never pushed a 6x to 240 mA. 160 mA was the momentary max from a challenge between DrLava and I one evening.
Go easy, draw your graphs because YMMV !!
Mike

Re: Here it is... 6x blu-ray in kryton, finally do

So a little update... it turns out I DID do my math right on the resistors but something went wrong with the driver itself. I was gone camping all weekend so I really didn't get a chance to look at it until tonight. I changed the driver back to its original configuration of one 33ohm resistor, and it was still putting out close to 300mA so something went funky with it I guess. Good thing I have a spare which I have been dialing in all night, and have it settled at 123mA with full batteries. The new drive should be here on tuesday or wednesday, so i'll be right back in the ball game!!

Re: Here it is... 6x blu-ray in kryton, finally do

Oh, you weren't turning the pot, but calculating the resistors needed for the desired current instead?

In that case it really shouldn't have gone wrong...

Re: Here it is... 6x blu-ray in kryton, finally do

yup. I'm not sure what happened to it really... All the solder joints look fine, no jumpers. So who knows... Just one of those things I guess