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Problem with LOC, AMC7135 and 2xaaa

spectral532

spectral532

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ReNNo said:
But I'm asking about AMC7135..
What will happen if I give 8.4V to AMC and diode?
Click to expand...

Like Eudaimonium mentioned, 8.4v is too much for the AMC7135 to handle. Even if you used diodes to drop the input voltage to 6v, the AMC would still have dissipate a lot of heat. You might be able to get away with a LM1117 version of the DDL driver though, albeit at a lower efficiency compared with the AMC7135.
 
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ReNNo

ReNNo

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Both drivers (with lm317 and lm1117) will have to dissipate heat because of high input voltage.
I don't think that Lm1117 will dissipate less heat.
Or I'm wrong..
 
spectral532

spectral532

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I think you are right about power dissipation. But a LM1117 will get you better battery life, since it can keep regulating at a full 1.5v below the LM317. If you are using 10440 batteries this would be particularly advantageous, since their small size means they dont have much capacity to begin with.
 
HIMNL9

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@ Eudaimonium: no problems, typo errors happens ;)



ReNNo said:
Both drivers (with lm317 and lm1117) will have to dissipate heat because of high input voltage.
I don't think that Lm1117 will dissipate less heat.
Or I'm wrong..
Click to expand...

LM1117 CAN dissipates less heat than the others, cause have a low dropout, so you need less Vin for have the same regulation at output ..... i mean, instead "eat" 2.5V from the input, it "eat" only 1.2V, and the dissipation depend both from the part of the voltage that you need to take away, AND from the dropout voltage .....

Said in other words, same example than before, if you need 3V and 100mA ..... with a 317, you have to use at least 5.5V in, so the dissipation due to the dropout of the regulator is 2.5V*0.1A=250mW for 100mA, where instead, the 1117 need 4.2V for give you the same current at 3V, so the power dissipated is 1.2V*0.1A=120mW ..... ofcourse, if you use the same input voltage for both the 2 regulators, the dissipated power is the same, cause the dropped voltage is the same in both the cases ..... like, if you power both with 6V, both of them need to drop 3V, so the dissipated power is 300mW for both the chips .....
 
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Eudaimonium

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spectral532 said:
I think you are right about power dissipation. But a LM1117 will get you better battery life, since it can keep regulating at a full 1.5v below the LM317. If you are using 10440 batteries this would be particularly advantageous, since their small size means they dont have much capacity to begin with.
Click to expand...
Or in my case, making pen bluray build with 2x 10440 and ddl driver possible.

Yeah, but I'm still not sure why the heck AMC is not outputting 350 mA...
 
LarryDFW

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HIMNL9 & Z;

You guys made me go back & look at the driver boards from my DVD burner drives a little more carefully:

The codes on the chips vary (some only have a letter & 117), but they are definitely #1117 LDO regulators:
1117.jpg

Also some are marked APL1117.
I have used several of them, and they all have about 1 vdc dropout.

Also there are some 3.3 VDC LDO regulators on the boards,
which I have used with a couple of Red diodes w/resistor.

LarryDFW
 
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HIMNL9

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Jerry, yes, this one is a 1117 ..... different manufacturers marks them in different ways, but usually all them respect the codes conventions, so if there are 3 "1", it's the right one ;)
 
LarryDFW

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HIMNL9;

Working with SMD's ...
I find very little convention in marking codes from boards screened:
"made in China" ,
as this DVD driver board was.

It is very difficult to determine actual part #'s from the abbreviated codes I see.

LarryDFW
 
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Eudaimonium

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Wow... I gotta look into my dissasembled drives for a little, maybe I can also find some 1117 regulators!
 
mfo

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spectral532 said:
If you want to power a 3.3v diode with 2xAAA, you will probably need a boost driver.

Alternatively, you can use a Lithium-ion battery. When fully charged, they output 4.2v, which should be sufficient to run your diode + AMC7135.
Click to expand...

He said it best. We all want cheap builds, but no matter how you look at it lasers are expensive.
 
HIMNL9

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LarryDFW said:
HIMNL9;
Working with SMD's ...
I find very little convention in marking codes from boards screened:
"made in China" ,
as this DVD driver board was.
It is very difficult to determine actual part #'s from the abbreviated codes I see.
LarryDFW
Click to expand...

Uh, true also this, you're right ..... time by time, i also find so much "funny" (just for not say "frustrating" :p) part numbers, on SMD IC, that, sometimes, i'm also wondering if they don't just invent their ones on-the-fly ..... when there was less of these units, and just a pair of sizes and shapes, it was more easy, but now, with too much sizes, shapes and models, is starting to become a mess ..... and yes, i also occasionally find different parts with the same codes .....

Normally, til the SOT cases, they respect these conventions (maybe except, as you said, the made in China products), but for the new products ..... :eek: (not speaking about custom units :wtf:)
 
Eudaimonium

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HIMNL9 said:
Uh, true also this, you're right ..... time by time, i also find so much "funny" (just for not say "frustrating" :p) part numbers, on SMD IC, that, sometimes, i'm also wondering if they don't just invent their ones on-the-fly ..... when there was less of these units, and just a pair of sizes and shapes, it was more easy, but now, with too much sizes, shapes and models, is starting to become a mess ..... and yes, i also occasionally find different parts with the same codes .....

Normally, til the SOT cases, they respect these conventions (maybe except, as you said, the made in China products), but for the new products ..... :eek: (not speaking about custom units :wtf:)
Click to expand...

Oof... dude, you have a really weird style of writing that is difficult to read fast, as I always read. I had to read your post letter by letter to figure out what you mean...

But yeah, basically I agree that they should write one marking for one model of regulator, and that's it. Especially the problem is that '1117' regulator is relatively new, and there IS a 117 regulator, so people get confused.
 
HIMNL9

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Eudaimonium said:
Oof... dude, you have a really weird style of writing that is difficult to read fast, as I always read. I had to read your post letter by letter to figure out what you mean...
Click to expand...

It's my guilty ..... it's cause my English is, mainly, self-learned from datasheets and tech dictionaries, and i have no occasions for use it in "normal life", so .....

Anyway, i can ensure you that i'm able, at least, to made authentic grammatical massacres also in other languages, not just in English ..... :p :D
 
Eudaimonium

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HIMNL9 said:
It's my guilty ..... it's cause my English is, mainly, self-learned from datasheets and tech dictionaries, and i have no occasions for use it in "normal life", so .....

Anyway, i can ensure you that i'm able, at least, to made authentic grammatical massacres also in other languages, not just in English ..... :p :D
Click to expand...
Grammatical massacres HAHAH LMAO :D
BTW, it is more appropriate so say:" It's my fault", not "my guilty"... it doesn't make sense.
 
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