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520nm advice

Mr Yagyuu

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Alaskan

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Maybe good, but since I live in the USA I avoid buying from China if I can, too many times there are problems and it costs too much to return the item. China sellers get a shipping subsidy from their government to make shipping out of country to us cheap, but we can pay far more than the item cost to ship it back. Also, too many of the China sellers are not ethical, they will say anything about their product to sell it.
Although there is one seller in HK I will buy from, Techhood, but in my experience, he makes too many mistakes with orders, or so he says they are.

Google "DTR LPF" to find Jordan's laser parts store, but where are you? Are you in USA or another country?
 

Mr Yagyuu

New member
Joined
Jun 16, 2016
Messages
53
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14
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0
Maybe good, but since I live in the USA I avoid buying from China if I can, too many times there are problems and it costs too much to return the item. China sellers get a shipping subsidy from their government to make shipping out of country to us cheap, but we can pay far more than the item cost to ship it back. Also, too many of the China sellers are not ethical, they will say anything about their product to sell it.
Although there is one seller in HK I will buy from, Techhood, but in my experience, he makes too many mistakes with orders, or so he says they are.

Google "DTR LPF" to find Jordan's laser parts store, but where are you? Are you in USA or another country?
Thank you

south korea here yet..

once i want a challenge to low power laser now.
start 520nm 50mw~80mw.
 

Alaskan

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Maybe shipping is much less for you, I have driven a PL520 single mode diode to 80mw output using two Li-ion batteries in series without a constant current driver,. Yes, wiring the batteries direct to the diode which is normally a bad thing to do, but this diode runs well and wouldn't fail for me when driven directly from the battery. When I reported this some have speculated the reason was due to having some resistance in the wires and voltage drop from that, giving the diode closer to its rated voltage, but I am not so sure that is why, I just think this is a very tough diode.

Still, would be a risk to wire the diode direct to the battery, yet DTR did some tests with this diode and if the current is a bit too high it just goes dim and recovers when the current is lowered to normal. Recommendation is to always use a driver, I'd use a boost driver with a single Li-ion battery with that diode. The reason I believe a boost driver might be better for this diode is this; when using a "buck" driver with two 4.2 VDC Li-ion batteries in series to produce 8.4 V from fully charged batteries it will add some voltage drop and if the batteries are drained too far, the diode might get less than the minimum 7.0 VDC required for 50mw output due to too low of a voltage.

Maybe this is a good thing as those batteries should not be drained below 3.7 VDC each anyway (some can go a bit lower) for a total of 7.4 VDC, but if using a buck driver, how much voltage drop does the driver add? If 1 volt of the battery supply voltage is being dropped through the driver, then 1 volt less is available to go to the diode, now when the batteries are 80% drained, you are down to 6.4 VDC supplied to the diode before the batteries are completely out of juice. To prevent this problem check the specs on the buck drivers to see how much voltage drop they produce, some can have a far lower amount of drop and choose one of those instead. Look for a driver which states "low dropout voltage". I believe most of the drivers you will find made for laser diodes will probably have a low dropout voltage, but not always. Of course, this isn't of concern with a boost driver, but I'd check to see what their specification is for the lowest input voltage they will operate at to provide the voltage and current you need for your particular diode.

Obviously, a buck driver with a very low voltage drop would be the better choice for this diode when running two batteries in series, if not to prevent the battery voltage from dropping too low before they are drained, additionally, to conserve battery power. No reason to waste power that way if you can avoid it, a buck with a high voltage drop will turn that extra power into heat instead of staying in your battery. Due to all of these reasons, IF you want to use a buck driver to allow the use of two Li-Ion batteries in series, I'd try to find a one with no more than half a volt of voltage drop.

Here is a link to a PDF document showing the PL520 diode specifications:

http://photos.imageevent.com/qdf_fi...ncelaserdiodedatasheets/PL_520_2012-10-23.pdf

Here is a link to Flaminpyro's stuff, including diode drivers:

http://laserpointerforums.com/f64/flaminpyros-stuf-67118.html

Here's a like to a manufacturer of low current diode drivers as well as other goodies:

http://www.aixiz.com

and last but certainly not least, DTR's google store and this guy ships fast for everything he sends, so if you need something in a hurry he is a good choice. Of course over seas shipments will take longer if you are not in the USA where he is at:

https://sites.google.com/site/dtrlpf/home/flexdrives

When I started this post (edited to add more) I didn't intend on writing a full page on this diode and drivers, but I kept coming back to add more information. Just that I'm bored at work right now, nothing going on. For all I know, this information is elementary to you anyway :p
 
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