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ArcticMyst Security by Avery

actual CURRENT? after the dead LD and resistor dum

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im asking if the actual current is the same as the current got in the dead LD and resistor DMM test?
 





chido

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Re: actual CURRENT? after the dead LD and resistor

Yes, whatever current measurements you get from a dead LD will be the same as the ones you'd get from a normal one. Although, just to be safe, after testing I wouldn't just solder the new diode without adjusting the current again.
 

chido

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Re: actual CURRENT? after the dead LD and resistor

Wait, so you tested it without a load? :-?
 
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Re: actual CURRENT? after the dead LD and resistor

you mean i will marked up the current adjustment in the dead LD, and then before i put the new LD, i will star again to higher resistance of the trimpot then try to reach the mark in the trimpot for the same current , right?
 

chido

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Re: actual CURRENT? after the dead LD and resistor

Well you got the idea, but I'd rather use a multimeter to measure the current istead of making a mark on the pot, just to be safer.
 
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Re: actual CURRENT? after the dead LD and resistor

i will answer your first question about the test without a load, yes i test it without a load with multimeter probe on its output without LED and i got higher than 3 volts at a current of 210. and for your second reply, i gonna ask if you mean the same way test as the dead LD and resistor to new LD? do i need to attach a resistor again befor the test for the new one?
 

chido

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Re: actual CURRENT? after the dead LD and resistor

You'll never get the right readings if you test your driver without a load, that's why you have to use 4 1N4001 silicon diodes, or a dead LD to simulate a working LD, the best choice would be a dead LD as it has the same resistance as a normal one.
Now, after you test the circuit to make sure it's working properly, you take your new LD and solder the capacitor and two wires directly to its leads to make sure it doesn't disconnect. Then you solder your negative wire coming from the LD to your driver, and then you take the resistor and place it between the positive wire of the diode and the one from the driver.
Turn your pot to maximum resistance, place your test prbes on both sides of the resistor (positive probe between resistor and driver, and negative between LD and resistor) (also make sure the multimeter is set to mV) Then set the desired current by looking at the mV and dividing them by the resistance of the resistor.
 
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Re: actual CURRENT? after the dead LD and resistor

ok i understand its the same way test for that, do i need to put out the resistor after i got the right current? and another about the voltage why is it higher than 3v without a load on driver output, is it dangerous to the LD when the power run through the output?
 

chido

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Re: actual CURRENT? after the dead LD and resistor

Yes, take out the resistor after you set the current. And don't worry about voltage, just worry about the current. Like I said, you didn't get the right readings since you measured without a load.
 
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Re: actual CURRENT? after the dead LD and resistor

ok that's great, what suppose to be the best resistor value when i use the open can on its sweet spot of current? is it ok if i combine 10ohm and 4.7 ohm a to have 3.12ohms?
 

chido

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Re: actual CURRENT? after the dead LD and resistor

Gazoo said the sweet spot for open cans is 400mA, and yes if you connect those in parallel, it should work. But just to be sure, check their resistance with your multimeter.
 
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Re: actual CURRENT? after the dead LD and resistor

actually i have actual resistance of 3.192 ohms from 10ohm and 4.7ohm, i have fresh 6volts input, can you give me a prediction what suppose to be the output for that going through the LD?
 
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Re: actual CURRENT? after the dead LD and resistor

guys i need some possibility guide, what was supposed to happen to my LD set up? i got on my DDL LD driver 3.192ohm total value of resistors, a adjusted trimpot and 6volts fresh battery for input. :-/
 

phenol

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Re: actual CURRENT? after the dead LD and resistor

adgmeijin said:
guys i need some possibility guide, what was supposed to happen to my LD set up? i got on my DDL LD driver 3.192ohm total value of resistors, a adjusted trimpot and 6volts fresh battery for input. :-/

with 3.19ohms of min resistance the max current would be ~390mA. Since you have a pot /what resistance?/ in series with the 10- and 4.7-ohm parallelled resistors, you can get any current starting from 1.25/(Rpotmax+3.19) to 1.25/(Rpotmin+3.19). If Rpotmin=0, the max current would be 390mA. just make sure your batt is always fresh or the LM317 will drop out.
 
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Re: actual CURRENT? after the dead LD and resistor

thanks a man this was a big help. ;D
 




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