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

Safe to cut alluminum tab off LM317T?

T

tehk

0
Joined
Feb 20, 2008
Messages
30
Points
0
Does anyone know if it would be safe to cut the aluminum tab that sticks off the back of the Lm317T?
I would like to know for space saving purposes. :D
Like this:
 

Attachments

  • lm317T_cut.JPG
    lm317T_cut.JPG
    7 KB · Views: 695





jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
tehk said:
Does anyone know if it would be safe to cut the aluminum tab that sticks off the back of the Lm317T?
I would like to know for space saving purposes. :D
Like this:
Click to expand...

No problem there...It is a common practice for building!
Jay
 
B

BlueFusion

0
Joined
Aug 15, 2007
Messages
1,880
Points
0
Yes but you still need to remember the exposed metal on the back is Vout and if it touches metal inside your host.... BAD THINGS can happen. You can release the mysterious blue smoke. After that electronics don't work anymore.

They operate on smoke signals ;) Let it out and poof! no more workies.
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
BlueFusion said:
Yes but you still need to remember the exposed metal on the back is Vout and if it touches metal inside your host.... BAD THINGS can happen. You can release the mysterious blue smoke. After that electronics don't work anymore.

They operate on smoke signals ;) Let it out and poof! no more workies.
Click to expand...

And that smoke smells sooooo good... ;D
 
T

tehk

0
Joined
Feb 20, 2008
Messages
30
Points
0
I may just have to fry one to experience this magic blue smoke :p
 
C

chimo

0
Joined
Jun 20, 2007
Messages
650
Points
0
tehk said:
Does anyone know if it would be safe to cut the aluminum tab that sticks off the back of the Lm317T?
I would like to know for space saving purposes. :D
Like this:
Click to expand...

As was mentioned:

1. Yes, it's OK
2. BTW, it's not Aluminium (plated copper perhaps?)
3. Don't short it to anything
4. Doing this will reduce the upper current carrying capacity of the IC (less thermal dissipation)
 
rog8811

rog8811

0
Joined
Jul 24, 2007
Messages
2,749
Points
0
If this is to be used with a fixed resistor you can do this with it and it will fit in a very small space......I did this for my red burner, it solders straight onto the circuit board of the host torch.

Regards rog8811
 

Attachments

  • lm317_space_save.jpg
    lm317_space_save.jpg
    27.2 KB · Views: 354
adgmeijin

adgmeijin

0
Joined
Oct 27, 2007
Messages
320
Points
0
hey bluefusion did you already sent to me the schematic diagram you are saying to my email? please inform me, thanks.
 
T

tehk

0
Joined
Feb 20, 2008
Messages
30
Points
0
rog8811 said:
If this is to be used with a fixed resistor you can do this with it and it will fit in a very small space......I did this for my red burner, it solders straight onto the circuit board of the host torch.

Regards rog8811
Click to expand...

That's pretty cool :D. I'm attempting to fit this in a 15mmx150mm flashlight tube. Everything needs to fit on either side of a little PCB board.
 
A

AP_Digital_light

0
Joined
Feb 29, 2008
Messages
41
Points
0
Read datasheet.

There are different packages:

SOT-223
TO-252
TO-263
KTE
D2 PAK

Or try version for kids ;-)

LM317L 100mA - TO92, SOP-8 and micro SMD package.

Beauty...
 
rog8811

rog8811

0
Joined
Jul 24, 2007
Messages
2,749
Points
0
Yeah it looks like it's plated copper
Click to expand...

It certainly is, which is why you can solder the resistor across the top as shown in my sketch above.

Regards rog8811
 
T

tehk

0
Joined
Feb 20, 2008
Messages
30
Points
0
rog8811 said:
If this is to be used with a fixed resistor you can do this with it and it will fit in a very small space......I did this for my red burner, it solders straight onto the circuit board of the host torch.

Regards rog8811
Click to expand...

So you just move the resistor(s) to that position and it gives the same result? So it will look somewhat like this?:
 

Attachments

  • Driver_edit.JPG
    Driver_edit.JPG
    36.3 KB · Views: 14,908
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
You only need to do it if you are working in a confined space such as a flashlight. And you don't need the pot as long as you know how much current the diode is capable of. The pot is more trouble than it is worth...IMO.
 
T

tehk

0
Joined
Feb 20, 2008
Messages
30
Points
0
Well i don't really know, I read somewhere that senkat's open can ones do ~250mw with plastic lens and ~300mw with glass but mines a 20x so i haven't seen what it's supposed to do.
 
You must log in or register to reply here.




Top