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ArcticMyst Security by Avery

Driver Design.

Joined
Aug 6, 2010
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382
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Instead of taking the time to argue with you about that, I would prefer to discuss your comments on the 7135 IC.

I'm not arguing. You are persisting on taking it of of context after I've explained the intent to you.

What is your theory on how you will be able to dump a few ma or regulate the output of a linear regulator?

The AMC7135 is off topic here now as far as I'm concerned as the OP decided not to use it. Surely you read that mine haven't arrived yet so why are you wanting to hijack his thread over a theoretical discussion on it?

Why not work with the OP, in his thread, on the 3 he is trying to use?
 





Joined
Dec 14, 2009
Messages
66
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8
I see what you are getting at now.
7135plusdiode640x480.jpg

(I only put one diode in the image, but of course you could add more)

That is essentially what the flashlight circuit boards from places like DX do already. However, I don't think it will allow input voltage to be any higher as the amc7135 still must regulate current to the load by burning off excess voltage as heat.

It is an interesting idea however. If the internal circuitry of the 7135 is limited to 6V (actually 7V max) but, the only thing limiting the output is the maximum power dissipation adding a diode on the Vdd pin might actually have some value. Especially if trying to drive a load that had a very high Vin, like more than 7V. I dunno if it would work or not. In the case of these laser diodes that don't require that high a voltage I would think it would be of no value.
 
Joined
Dec 14, 2009
Messages
66
Points
8
Nope just very helpful.
I plan to do the test today and find out how they work with a test load then put it to a nice red then maybe blue laser.
some of these things are so small.

Well, hows the testing going? Very curious to see how those I.C.s handle output less then minimum rated voltage.
 

Benm

0
Joined
Aug 16, 2007
Messages
7,896
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113
You got the drop diode idea right in that drawing. The specs on the amc7135 state 6 volts input voltage as the maximum operating limit, and you should stick to that. The 7 volts is an abolute max rating - that only means the ic will not be damaged at 7 volts, not that it will still function properly.

I'd recommend using a couple if 1n4148 diodes to bring down the voltage to safe levels, and adding a capacitor between the chips positive voltage and ground for good measure too.
 




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