help with ddl driver

[Meatball]

A 1/4 watt resistor would get hot in lots of DDL circuits, while it gets hot, its resistance would then increase, resulting in less current to your laser. However, for this specific application, I can't necessarily say that a 1/4 watt resistor wouldn't work, but for not but a few cents more, with no harm done electrically, its simply safer to go with the resistor that can handle more power. You should only have to consider using a 1/4 watt resistor if you have a HUGE amount of space limitation in your build, but 1/2 watt resistors aren't even that much larger in size. I usually like to play it safe.

 

[mattmagic100]

okey dokey so i should use a 10ohm 1/2 watt resistor for both the test load and the circuit right?

 

[Meatball]

10 ohm on your circuit, 1 ohm on the test load. Keep reading around on the forum, you'll get it!

 

[mattmagic100]

okey dokey but the link you gave me with the resistors at radioshack goes into the test load right?

 

[Meatball]

nope, into the ddl cicuit, they are 10 ohm, not 1 ohm. The resistor that you posted a link to, is wirewound 10w resistor... huge overkill for a test load. I'm not sure though, if the inductive properties of a wirewound resistor will affect a test load test... hmm.. :/

 

[mattmagic100]

o okey dokey i see. k well i did everything. i just need a 1ohm resistor.....WHICH I CANT FIND ANYWHERE!! >=[
haha =P

 

[mattmagic100]

does anyone know where to get a 1 ohm resistor in a store that i can go to instead of ordering?. or if there are some in a certain device.
thanks!! =]

 

[The_Muffin_Man]

i couldnt find a 1 ohm resistor either. You have a couple of options though. On mine i used a 3 ohm resistor. The only thing that needs to be done is to multiply the output (the reading on the DMM) by .333. Or you could use ten 10 ohm resistors to get a 1 ohm...Ill try to find the link where the guy did that...