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ArcticMyst Security by Avery

2xAA blue ray driver (fits in aixis)

IgorT

IgorT

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Wow, i've been away, because of all the work and preparations, but i just had to check back. This is nice!

Would it be easy to add the other coil to this design? There seems to be enough space on the other side. Or would it affect the layout too much?
 





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woop

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IgorT said:
Wow, i've been away, because of all the work and preparations, but i just had to check back. This is nice!

Would it be easy to add the other coil to this design? There seems to be enough space on the other side. Or would it affect the layout too much?
Click to expand...
for sepic operation?
possibly... probably. i will try it tomorrow, i should probably sleep now
i should design it for coupled inductors to save space and increase efficiency
although this table doesn't look very promising http://www.coilcraft.com/lpd4012.cfm

i tried ordering some lm3410's and they wanted to charge me shipping because it is a popular sample... how many have you been ordering igort? ::)
i think they are on to us. a google search for lm3410 turns up with LPF on the bottom of the first page.

anyway after i ordered, they told me that i needed to pay, so i closed that window, and now i can't find the option to pay for that sample order. and i can't order again because it doesn't let you order the same thing twice.
maybe if i don't pay, they will just send them out anyway :-?
 
IgorT

IgorT

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Oh, that's bad.... But i don't think many people have been ordering. And i doubt, they google their own products. ;D

BTW, didn't you have to pay for the shipping the first time as well, because you don't have a business address?


A coupled SEPIC coil would be nice, but if another one fits on the other side of the PCB, and it all can go into an AixiZ module, there really is no point. The boost circuit you made is perfect for BRs, but it would be great to have something for reds, or rather something universal, as well.


I could probably send you two ICs and four inductors, if you need them, and i'll try to order more. If i can, i would gladly send you more. It's the least i could do, after you drew these nice circuits. You should get to use them as well. :)
 
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toked323

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Hey Igort, if you have an extra IC you want to sell, ill buy one off you, if its cheaper than semi.
 
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woop

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you can buy them for $3 each from digikey http://www.digikey.com/scripts/dksearch/dksus.dll?Detail?name=LM3410XMFCT-ND
and the lt6106 for $2
http://www.digikey.com/scripts/dksearch/dksus.dll?Detail?name=LT6106CS5#TRMPBFCT-ND

BTW, didn't you have to pay for the shipping the first time as well, because you don't have a business address?
Click to expand...
I used my university address this time, and they accepted that and didn't charge shipping, they tell you after you have ordered (if you use a gmail address, they tell you shipping costs before you order)

coupled sepic will also make the converter more efficient, unfortunately the only coils that fit are too low current at 4.7uH
 
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woop

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phenol

phenol

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caps look ok, a bit pricey, though :eek: note the 10V rating <- this one wont work in SEPIC configuration as C3 (as per datasheet of LM3410)
the sense resistor is 1ohm. how about 0.1ohms? If you want to go wit the 1ohm version, you have to use a bigger one - in 1206 or larger footprint. Those 0805 ones are rated for 125mW max.
trim pot is great, too. it looks well protected from dust and solder rosin.
 
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woop

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phenol said:
caps look ok, a bit pricey, though :eek: note the 10V rating <- this one wont work in SEPIC configuration as C3 (as per datasheet of LM3410)
the sense resistor is 1ohm. how about 0.1ohms? If you want to go wit the 1ohm version, you have to use a bigger one - in 1206 or larger footprint. Those 0805 ones are rated for 125mW max.
trim pot is great, too. it looks well protected from dust and solder rosin.
Click to expand...
oops did i post the 1ohm one? i meant to chose 0.1
why won't 10v work for sepic? the sepic schematic only calls for 6.3v.
ia 25c a lot for a smd capacitor? how much should i be paying
 
phenol

phenol

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AN-1775.pdf <- look here for C3 voltage rating (2.2u/25V)
As of cap price...the 1206 footprint version sells at $0.043 for 10-99 pcs here. You could also look for suitable caps on harvested DVD burner boards
 
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woop

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the voltage across c2 should be the same as the voltage across c3 which should be the voltage across the diode and sense resistor, which should be under 10v for any laser!

You could also look for suitable caps on harvested DVD burner boards
Click to expand...
which is what i have been doing until now, but i am trying to figure how much it would cost to make 10 or so, to sell
 
phenol

phenol

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woop, i think we are talking about different components here. i take it you are referring to the component designators of your circuit on the previous page. In this case-yes, 10V caps would be sufficient.
im talking about C3 in the SEPIC configuration in either the datasheet or the application note. In the case being , the BOM calls for 2.2uF/25V. In reality, the voltage across that cap in steady state equals Uin, which is normally not higher than 5-6 volts, but there are occasions when the supply of the power switching section of LM3410 can go higher than the chip logic supply (high BV of the output n-channel FET).
Also, the bigger size of the 25-volt cap fits better on their PCB ;)
 
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toked323

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hey if anyone wants to sell an lm3410 let me know , i hate dealing with companies
 
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woop

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toked323 said:
hey if anyone wants to sell an lm3410 let me know , i hate dealing with companies
Click to expand...
that is irrational. you can get 5 lm3410 samples from national shipped for $9.50
thats probably the best deal you can get after free shipping.
 
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woop

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If anyone makes one of these, remember to have reverse polarity protection on the driver. :-[
 

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phenol

phenol

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::) the shunt is well done, LM3410 too, the tantalums look rather rare... I blew one of these powering it w/o load. The NMOS switching transistor channel became a dead short thereby shorting power from batteries as well. Thats why I placed a tiny fuse in series with one of the power supply wires and a diode (1n5819) in reverse across + and gnd. should polarity inversion occur, the anti-fool protection becomes forward biased and blows the fuse.
BTW, i see that you have placed a small smd cap on the LD terminals.
 
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woop

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phenol said:
::) the shunt is well done, LM3410 too, the tantalums look rather rare...
Click to expand...
the shunt and tantalums are still ok, they always looked like that :-/

I blew one of these powering it w/o load. The NMOS switching transistor channel became a dead short thereby shorting power from batteries as well. Thats why I placed a tiny fuse in series with one of the power supply wires and a diode (1n5819) in reverse across + and gnd. should polarity inversion occur, the anti-fool protection becomes forward biased and blows the fuse.
BTW, i see that you have placed a small smd cap on the LD terminals.
Click to expand...
thats a good idea. i will do that next time i make one. what did you use as a fuse?
and yeah the small cap is a good idea, i didn't want to risk it.
btw the laser diode still works :D
 
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