Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Running Multiple Lser Diodes. (NUBM08)

DashApple

DashApple

0
Joined
Jan 14, 2009
Messages
1,452
Points
83
What are you after

Three regulators in parallel running one string of 8 diodes at 3.5A ? or one regulator running one string of 8 diodes at 3.5A
 
Last edited:





B

Bowler

0
Joined
Dec 5, 2016
Messages
37
Points
0
Both.. I want to know what the drop out voltage will be, or if they even change at all! when they are in series or parallel. That's it.
 
DashApple

DashApple

0
Joined
Jan 14, 2009
Messages
1,452
Points
83
Ok , Ill have a look at working it out .

Forward drop with three regulators in parallel will be abit less them one on its own for the same total currently as with three in parallel the total current is shared across them so they will drop less voltage


In theory : P
 
Last edited:
B

Bowler

0
Joined
Dec 5, 2016
Messages
37
Points
0
No all I need to know are my questions.
a) What is the drop out voltage on 1 LM317 - I know its 1.5V
b) If I put LM317 in parallel does the volt drop stay the same? - I think it does
c) If I put 2 or more LM317'S in parallel does the Volt drop add up? - I am not sure

I need to know this so I can determine the correct power supply to counter the Volt drop out. Simple.

Can you see where I am coming from
Thanks
 
Last edited:
DashApple

DashApple

0
Joined
Jan 14, 2009
Messages
1,452
Points
83
Bowler said:
No all I need to know are my questions.
a) What is the drop out voltage on 1 LM317 - I know its 1.5V
b) If I put LM317 in parallel does the volt drop stay the same? - I think it does
c) If I put 2 or more LM317'S in parallel does the Volt drop add up? - I am not sure

I need to know this so I can determine the correct power supply to counter the Volt drop out. Simple.

Can you see where I am coming from
Thanks
Click to expand...

a) Voltage drop of the regulator will vary with current , look at drop Vs current graph in data sheet . Only thing consistent is the 1.25V across the current set resistor .

b) Depends on what current they pass

c) Nope
 
Last edited:
B

Bowler

0
Joined
Dec 5, 2016
Messages
37
Points
0
Hey Guy can you help me out here please :)

what would the Dropout Voltage be / Head Room on Styropyro's Laser shotgun ?
Because he has 8 parallel sets with 3 Lm317's in series.

Would the Head room add up or would it just be a couple of Volts as always.

Thank you, please help!
 
B

Bowler

0
Joined
Dec 5, 2016
Messages
37
Points
0
Mate what you going on about now... Check my last comment.

I have checked and it is 3V.
 
diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Bowler said:
Mate what you going on about now... Check my last comment.

I have checked and it is 3V.
Click to expand...


What are you going on about? Your comments aren't making a whole lot of sense...

I'd suggest starting out with something simpler before going ahead with this project. The requirements appear to be above your current understanding. It'd be best to learn the basics and work your way up.
 
Cyparagon

Cyparagon

0
Joined
Sep 12, 2007
Messages
9,399
Points
113
Bowler said:
the drop out voltage on 1 LM317 - I know its 1.5V
Click to expand...

Bowler said:
I have checked and it is 3V.
Click to expand...

2464HJ2.gif


So which is it, smartass?

Spoiler: both are incorrect. What's worse, is that this has been answered several times here, and you're still wrong twice.

Bowler said:
I've done a lot of maths and I understand this stuff as I'm a qualified electrical engineer.
Click to expand...

As a "qualified electrical engineer", you would not ask if two regulators in parallel would have different voltages. You would immediately understand that was impossible. As I am now reasonably certain you are

A) f:)cking with us, or
B) lying or misrepresenting yourself or your intentions,

You can have some red bars. I've had quite enough.



gw4CUB5.gif
 
diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Bowler said:
Man youre an asshole, sort your life out
Click to expand...


He's also one of the most experienced members on this forum, someone you'd better not alienate if you'd like help. Oh wait ... too late. And for what it's worth, I've come to the same conclusion as Cyp did in his last post.
 
Last edited:
B

Bowler

0
Joined
Dec 5, 2016
Messages
37
Points
0
I dont care who he is. and most experienced member lol.. he cant even answer my question about styro's circuit and what the headroom is when you have 3 lm317 in series in a parallel... all I'm looking for is help. Best member here is red; hes a star. rest of you need to sort your lves out lol, attitude is so bad.. He's a moron and so are you if you think that...
 
diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Bowler said:
I dont care who he is. and most experienced member lol.. he cant even answer my question about styro's circuit and what the headroom is when you have 3 lm317 in series in a parallel... all I'm looking for is help. Best member here is red; hes a star. rest of you need to sort your lves out lol, attitude is so bad.. He's a moron and so are you if you think that...
Click to expand...


See, your question doesn't even make sense.

what the headroom is when you have 3 lm317 in series in a parallel...
Click to expand...

What does that even mean?

Your attitude has not only alienated Cyp and myself, but will likely also result in everyone else refusing to offer any further help. I'm certainly done offering any assistance.

giphy.gif
 
Last edited:
You must log in or register to reply here.




Top