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100ohm, 1000ohm whats the differennce ?

J

jamie.91

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Hi i am a mkaing a diy red and today i went to maplin to get my parts for my ddl driver
first ov all the guy says "the 1N4001 diode" i say yes he says "glass or slicon"? i didnt have a clue so i say both and god knows which one i have put in the driver lmao :D
but then he says "we dont have the 100ohm variable resistor, 1000ohm is the least we have" so impatiently with my temper growing i say yes it will have to do
BUT THEN i get home and realise he has given me a 10uf capacator not a 10mf 16v, now i dont know the difference but its not right , right ?
aanyways i make the driver with what parts i have but dont have a diode yet so in desperation i link up an led to try and see if i can get power, guess what not a flicker ?

Could it be the capacator, diode, resistor or all of them please help me

thanks jamie
 

rkcstr

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Difference between 100ohm and 1000ohm? 900 ohms ;D

Silicon diodes are the usual type, just make sure they're rated >500mA

10mf is typically an equivalent designation for microfarad or uf, so if you were thinking millifarad, it is not commonly seen in small caps.

So, if you built your driver using a 1000ohm variable resistor you're only going to get 1.25mA of output at it's highest setting, but at the lowest resistance, it may be a few ohms or more.

At this point, it may be best to post some pics, give more details like what battery type/voltage you're using, what type of LED you tried, that you have the LED hooked up correctly, and much more. It sounds like you're not very sure of what you're doing, so I have a good feeling something isn't correct.
 

docjohn

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jamie.91 said:
Hi i am a mkaing a diy red and today i went to maplin to get my parts for my ddl driver
first ov all the guy says "the 1N4001 diode" i say yes he says "glass or slicon"? i didnt have a clue so i say both and god knows which one i have put in the driver lmao :D
but then he says "we dont have the 100ohm variable resistor, 1000ohm is the least we have" so impatiently with my temper growing i say yes it will have to do
BUT THEN i get home and realise he has given me a 10uf capacator not a 10mf 16v, now i dont know the difference but its not right , right ?
aanyways i make the driver with what parts i have but dont have a diode yet so in desperation i link up an led to try and see if i can get power, guess what not a flicker ?

Could it be the capacator, diode, resistor or all of them please help me

thanks jamie
Jamie : thats a lot of questions, but I'll try to help. :) a 1N4001 is a 1N4001. glass or silicon should not make any difference in your usage. . The problem with a 1000 ohm pot is that it will be at least 10 times more difficult to adjust for the resistance you want. it will be extremely sensitive at the point you want. (also it depends on the taper--another subject) the 10 uf cap should work.(uf is the same thing as mf. they both mean micro farad. It is unlikely that it is rated below the voltage you will be using. So I guess I am saying that the parts you have should work except for the 1000 ohm pot. It is way to sensitive! how do you have it all hooked up? :-?
 

rog8811

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check your connections against the drawing below, the commonest mistake builders make is to have the output to the LD coming straight from the output leg of the LM317, it doesn't, it comes from the ref leg. One other thing, if you are using the new SenKat red LD put in an extra 10ohm resistor next to the two shown giving you 3.3ohms insteade of 5ohms.

As rkcstr says, post some clear photo's.....

Regards rog8811
 

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diachi

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The All those components should do fine, with the cariable resistor you can just adjust to the resistance you want, but its gonna be some hell of a time, as it will be really sensitive ! You should get it working with some patience.

Diachi
 

GooeyGus

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I use a 1000ohm variable on my testing driver, but its a 13-turn pot. How many turns is yours, just one?
 

GooeyGus

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Ahh... from your pictures it looks like you're only using one 3v/3.6v battery. You need a minimum of 6v with that driver. And a bit more is recommended for a longer run-time and higher currents. I would use two 3.6v cr123a's.

EDIT: I just read your page again, it says you're using a 6v battery. This should give you enough to at least a bit of light. Hmmm... Next I would try turning the screw on your pot clockwise until the diode lights up. If you still get nothing, check all your connections, and make sure the orientation of all your components is correct.
 

GooeyGus

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Just looked again, it looks like the orientation on your silicon diode is wrong (as long as your red wire is + and black is -). I could be wrong since I cant see how everything is soldered underneath, but it appears like its opposite of what it should be. The side with the thick gray stripe goes to the positive.
 

rog8811

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Nice web page, well writen up project, could you post a picture of the back of the circuit board as it will help with fault finding?
I strongly suggest you get yourself a cheap multimeter as you need to take some measurements from around the circuit to understand what it is or isn't doing. Test it using the information from this thread....
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197651171


Regards rog8811

*Can I just point out a spelling error that jumps out of the page? Bored should be board.*
 
J

jamie.91

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GooeyGus thanks for the great help i shall try unsoldering it and turning it round lol

thanks jamie

BTW thanks for the spelling mistake i shall change them soon lol
 
J

jamie.91

Guest
IT LIVES !!!

GooeyGus you are my hero ;D

i swapped it around and now the grey band is the posotive

i appreciate your help a lot

thanks,thanks,thanks jmaie
 




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