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FrozenGate by Avery

FINALLY building a Blu-Ray!!

T

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Well with ALOT of help from Hemlock Mike, I am finally going to build a blu-ray!!! I bought one of the DIY DDL component kits from SenKat, and apparently it works for Blu-Rays too. Is there any mods i have to do to the circuit? What power do you recommend running it at? I don't care if it doesn't pop balloons or whatever, just so i get a nice life outta it? Having a variable output from like 0-40ma or so would be good, so im thinking all id need is a resistor in series with the pot? How do you think i should do this?
Thanks
 





Now, I'm no expert, so take this advice with a pinch of salt.

IIRC, the DIY kit contains all that stuff i.e. the pots etc.

Just make sure, as you correctly stated, you have a max current that the regulator will output, set by a fixed resistor and you'll be fine!

Dan :-)
 
AHhh ok, what i was thinking of doing, is stick a resistor in series with the pot, so i have a sorta adjustable output. So if i can find a resistor value that will limit the current to 40ma, no matter how low the pots resistance is, then i can adjust power from like 0-40ma MAX , good idea or not? Now i gotta find the right resistor value.
 
That's correct - if you have a resistor that allows a MAX current of what you want to safely drive the diode with (ie., 40mA) then you can always stick a pot in there in series with it to give you the variable output you're looking for. I've done this with my DIY reds and it works well. I have a bunch of small 20 ohm trimmers on ceramic substrates so they can handle the power (heat dissapation is great), and I can adjust my total resistance from 4.7 ohms to 24.7 ohms. If you're using DDL's driver, just divide your ref voltage (1.25) by the resistance to get your milliamps to the diode. So, 5 ohms = 250mA, 10 ohms = 125 mA, etc.

Dave
 
so according to that, i will need 28 ohms across adj and out to get 48 or so ma? What current do you think MAX, i should run into this thing, so i get a good lifetime outta it?
 
i had seen that a 33ohm resistor works great for the blue ones, i think it limited the current to 40ma, i may be wrong tho :D

...lazer... ;D ;D ;D
 
I've read that 35 mA is a good safe setting.  My pocket BR runs at 40 mA because that's what I got with the resistor I stuffed in there !!  I'm using a 78L05 as a voltage regulator.

The BR will pop a balloon and light a match at about 55 mA -- HOWEVER --
you quickly loose a diode  :(

Mike

Do you need a 78L05 ?
 
Ohhhh ok, so using the DDL driver, i would need a 33ohm resistor to get a MAX 40ma, no matter what the pot is set on? It will be adjustable, but i'm working on getting it so that it CAN'T go any higher than 40ma. Right?
 
I think the 33 Ohm sets the max current to about 40 mA.  You should experiment. 33 Ohms in series with the pot.

Mike
 
yep, Gazoo says its 33ohm too. Well thanks guys, now all i gotta do is wait for my diode!
 
Things -- It ships tomorrow !! ;D
I can poke a hole in the box for a regulator if you need it !!
Mike
 
Thanks Man! I already have a DDL driver kit for it, so i think i should be good to go! ;)
 
Is it just my regulator, or does the mA's increase exponentially? Is it something to do with having a logarithmic pot (or the lack of) in the circuit? It get very fine adjustment on the low end, then it rockets up. I just bought normal pots from Maplin electronics.

I read something that log pots were used in audio speaker volume control, to give the effect that they were increasing their volume at a constant rate (by changing the resistance exponentially)

Right?, wrong?, or do I have a messed up circuit?


Dan :-)
 
@ Dan, you are correct in thinking about how log pots work but I would be very suprised if that is what you have got.

When I set up my blue rays I got the same feeling that the increase in ma was faster once lase point was reached but I know my pots are linear. If it is a real effect I can only assume it is something about how the regulator works.

Regards rog8811
 
danielbriggs said:
Is it just my regulator, or does the mA's increase exponentially? Is it something to do with having a logarithmic pot (or the lack of) in the circuit? It get very fine adjustment on the low end, then it rockets up. I just bought normal pots from Maplin electronics.

I read something that log pots were used in audio speaker volume control, to give the effect that they were increasing their volume at a constant rate (by changing the resistance exponentially)

Right?, wrong?, or do I have a messed up circuit?


Dan :-)
Click to expand...


I'm not sure. If you post a picture, then we can certainly tell you if the circuit will work or not. Just need some pictures.
 
Pots usually jump up a fair bit at the end. I hooked a LED up to a pot, in a way that it was brightness controlled. About 3/4 of the pot did nothing, and in the last quater, it went from off to full brightness. Thats why the lower the resistance of your pot, the finer the adjustments you can make.
 
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