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FrozenGate by Avery

Testing DDL Circuit with multimeter

Oh, I want to run this off of a 9v battery. Will upping the voltage up the current, so maybe i dont need to add another resistor?
 





Viroy, I've said this many times already, you don't have to worry about the voltage, the diode will take whatever voltage it needs as long as the current is fine. And also, (I've said this before) the power to the diode won't change even if you up the input voltage. The power going to the diode will drop, but only if your input voltage gets below 6v. You could put in 20v into the driver if you want to but the current going to the diode will stay the same since your resistors and pot are limiting it, and if the current stays the same, the voltage going to the diode won't change either.
 
cool :)

Ok now eventually I want to run up to 5w dpss 808nm diodes... The lm317 wont handle that, so what would you reccomend?
 
I couldn't tell you. Since not a lot of people use 5 watt monster diodes I don't know of a driver that can run one.
 
Well come to think of it... I guess I dont fully understand why we are taking the ma measurement across the 10 or 1ohm resistor.
We are measuring the difference?
 
It's just ohms law.
Ohms law states that I/R = E (amps/resistance = volts)
So if you want to drive your diode at 200mA, you get the 1 ohm resistor and apply ohms law. .200 amps/1 ohm = .200 volts. This is why 1mV = 1mA when using a 1 ohm resistor.
 
hmm radio shack doesnt have any micro-pot's under 10k ohms :(
im going to look on ebay for now i guess.. can you reccomend a place for good pots?
 
I couldn't find the 100 ohm version of that pot but I did find the 500 ohm one and it seems the pot is rated for .1 watts only. :(
For red laser diodes you need at least 1/2 watt pots. (maybe 1/4 watt if you don't go over 200mA)
 
Hey Chido! ya still around? :)
Was hoping you could help a lil more o' wise one
i now have the need to step up from 3v to power the ddl circuit.
im trying to integrate the ddl circuit with another circuit board, that board has a 3v power jack(pins) right on the circuit board itself that i can use.
the device uses a 9v 600ma power supply so i thought i could run right off of that but... what i did was solder a lead directly to the negative of the power input, and a lead to the positive of the power switch (this way the device and the ddl circuit would power on at the same time). but when i powered it on, the POT on the ddl circuit glowed red hot and started smoking bad. i immediately turned it off but the damage was done, the ddl circuit is fried (atleast the POT) plus the laser is now damaged and only half as bright with a new ddl circuit.

so it seems i have 2 options.. best option would be to step up 3v to atleast 7.5v so i could take advantage of some of the features on the other circuit board... or, do i need a resistor to run off the same positive and negative leads maybe?

this is my *guess* as to whats happening... the other circuit draws way more current than the ddl circuit, so the ddl circuit is basically getting caught in the wake of what the other circuit is drawing. i need to isolate the power source into two, or limit the maximum that can be delivered to the ddl circuit?

ideally though i would really like to step up 3v to 7.5-9v.
i did find this from one of the earlier posts, but i dont know how to use it properly to go from 3v to 7.5v
http://cache.national.com/ds/LM/LM3410.pdf

*ps - the reason im saying atleast 7.5v, is because that is the lowest power setting i have gotten my laser to work with using the ddl circuit. my next lowest option was 6v and i get an extremely dim dot from that, definitely not enough.
 
but i guess right now i just want atleast one working.
can i use a resistor on the input wires?
 
ah i found dr_lava's flexdrive thread and just ordered one!
these look like the shiz! so small and everything all on one board!
 
So is there a difference between the diodes in PHR-803T sleds and the KES-400 sleds?
i think i read somewhere that they are both blue but use different wavelengths?
 
viroy said:
So is there a difference between the diodes in PHR-803T sleds and the KES-400 sleds?
i think i read somewhere that they are both blue but use different wavelengths?
Click to expand...
They are both violet, but the PHR-803T sled is capable of over 100mW while the KES-400 sleds are only capable of 20mW.
 
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