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

powering a green module off a higher voltage lm317

hugo999999

hugo999999

0
Joined
Feb 19, 2010
Messages
443
Points
0
hi
i would like to run a green laser module from DX for my laser spirograph off a single wall inverter with the motors. is it possible to power a green laser module that normally runs on 3v off a higher voltage by simply sticking an lm317 regulator in front of it? do i need to add anything else such as resistors etc?

thanks in advance!

Hugo.
 





aXit

aXit

0
Joined
Sep 15, 2009
Messages
206
Points
0
No, nothing like it.

If you were to desolder the driver and power the diode straight from a DDL driver, that could work, but what you want is this:

voltage-regulator.png


Ignore the variable nature of R2, set resistors are fine.
 
hugo999999

hugo999999

0
Joined
Feb 19, 2010
Messages
443
Points
0
thanks for the schematic i may try this later. not sure what resistor values to use though for it :thinking:

also what if i simply attached a DDL driver straight to the existing driver? would that work?

thanks, Hugo.
 
hugo999999

hugo999999

0
Joined
Feb 19, 2010
Messages
443
Points
0
screw it ill just get some 3v regulators or use a 5v and some diodes :D
thanks anyway
 
chipdouglas

chipdouglas

0
Joined
Dec 23, 2008
Messages
3,948
Points
63
actually the resistors will regulate the current. the lm317 will regulate the voltage,, i believe up to 24vdc. so if you only need 3 volts all the extra volts will be converted to heat. but i think you could use the lm317 no problem because you can still keep your factory driver in place.
 
jaycey

jaycey

0
Joined
Apr 10, 2009
Messages
480
Points
18
DDL drivers work fine with green modules.

You just need to measure how much the standard driver is putting out and then remove the standard driver. Workout what resistance you need to achieve desired output
then connect the DDL to the green module diode.

You will need heatsinking on the LM317 though.
I have 2 50mw greens on DDL drivers (1 is the FML 3 colour driver) set to give a max of 450mah
 
Last edited:
Benm

Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
Sure it will - but that involves removing the existing driver. Doesnt have to be a problem, but some people might not like removing it.

You have 2 LM317 options really:

- LM317 wired as a current source, directly on the pump diode (discard original driver)

- LM317 wired as a voltage source, keeping the old driver

The first option has the benefit of being able to set the current to whatever you like, the second is easier to rig and keeps the factory driver responsible for regulating current (i.e. less likely to blow the diode up).
 
BShanahan14rulz

BShanahan14rulz

0
Joined
Dec 29, 2009
Messages
3,136
Points
63
User wants to run a 3V module safely on higher voltage. Obvious solution is to use a 3V regulator, such as an LM317.

The LM317's voltage adjust function can be used to create a constant current regulator, and around here, this seems to be given the name DDL. This DDL, however, is NOT the same as hooking an LM317 up to be a voltage regulator, although they look similar.

Just trying to clear up some confusion.
 
chipdouglas

chipdouglas

0
Joined
Dec 23, 2008
Messages
3,948
Points
63
the lm317 is a voltage regulator the ddl is named after the member who more or less created driver Daedal.... the ddl driver is a complete driver which incorporated the lm317. the lm317 is just a voltage regulator good up to like 20vdc. and there isn't a "voltage adjust function" it is auto ranging. and remember that the bigger gap between used voltage and the voltage that the regulator is good for will cause excessive heat. so use good heat sinking



michael
 
hugo999999

hugo999999

0
Joined
Feb 19, 2010
Messages
443
Points
0
ok thanks everyone!

i will probably use the lm317 as a voltage source and keep the original driver as a current limiter. how would i wire it up? just stick the lm317 in front of the green driver?

i believe that the 1st pin in lm317's are voltage out, 3rd is voltage in, and the middle pin is adjacent or something like that?

Thanks for your help, Hugo.

p.s. yes it will have an absolutely huge heatsink, i just got a big sheet of aluminium for free :D
 
Benm

Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
Just do what the datasheet suggests as configuration for a voltage source then.

You should end up with resistors in the order of 1k5 and 1k in the feedback circuit part - or at least something of comparable ratio.
 
aXit

aXit

0
Joined
Sep 15, 2009
Messages
206
Points
0
Yes you "stick it in front" of the original driver.

That other pin "adj" is the adjust pin, you use it to adjust the output voltage with resistors.

voltage-regulator.png


R1 as a 240ohm resistor, and R2 as a 330ohm resistor.

That will give you Vout as 2.97V, which the driver can handly perfectly fine.
 
Benm

Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
That's the reference circuit alright. 330/240 sounds as a good pair of values for the resistors too, although you might want to err on the high side here and choose 330/220 or 1k5/1k.
 
You must log in or register to reply here.




Top