Problem bucking a PL520

[scumbagatheist]

Ok...I found the Blitz-Linear. It can handle the Vout for the PL520. Can DTR weigh in and tell me if this diode is case-isolated? Cause I am fairly sure the host is not isolated. But, I always use my diode leads and never rely on the host...

Does this sound like it will work?

 

[Wolfman29]

It should work. That's why I designed it - with these diodes specifically in mind. The diode is case isolated. Further, the ripple input should be fine. Just recognize that these drivers are continuous positive rail, so your host will need to be case positive.

 

[TheDukeAnumber1]

I think you should try barking up Le-quacks tree. He has made a buck/boost driver that I think would handle a 520nm. I would definitely put it on a test load first though. Jufran88's test load should be able to mimic one.

 

[scumbagatheist]

I will hit him up and see what he says.

My Moh linear was tuned to 305mA and run on Jufran's load, but I don't think the load ever managed 8V. I think it was the lack of current.

I'm sure the Moh is running right. I'm just afraid to hook it to a $145 diode before having more data. I'm sick of killing diodes.

 

[TheDukeAnumber1]

It kinda seems silly to try a linear, pretty sure it has to have a volt or two supplied over the Vf to operate and since your absolute max is kinda near the Vf you won't get the runtime you should. Perhaps just boosting from 2 C-batteries is your option although I think it would be wiser to run a 3.7 and a spacer. Not sure which are get you more runtime.

 

[scumbagatheist]

I appreciate your perspective, Duke. Silly or not, this is a good learning experience. DTR says I shouldn't cause any damage to the diode if the linear isn't regulating. I'll keep doing my homework for now. It's not like the host is here yet anyway...

 

[TheDukeAnumber1]

Nothing wrong with that. I understand how learning empirically goes, I've killed a bunch of diodes myself. Hopefully Le-Quack comes through for you and you get the best of both worlds.

 

[jayrob]

It will work well with a custom build X-Drive to what ever current setting you need...

But depending on the voltage that your diode is asking for, will be the run time.

So if your diode is asking for 7 volts, your diode will begin to drop out of regulation when the cells get near 7 volts, but with those size cells, I'm guessing your run time will be a long time because the current setting will be low. You will have very little heat with that driver...

 

[scumbagatheist]

Well, it appears as if my problem has been solved. The 290mA X-Drive will work with the PL520 and use my two massive batteries at the same time and do it quite efficiently as well. I've not yet used this driver, but I do like the X-Boost.

 

[scumbagatheist]

Thanks Jay..you must have been posting that right as I was making my last post. I just ordered 2 of them.

 

[jayrob]

Well, it appears as if my problem has been solved. The 290mA X-Drive will work with the PL520 and use my two massive batteries at the same time and do it quite efficiently as well. I've not yet used this driver, but I do like the X-Boost.

Yep, lazeerer makes nice drivers...

The X-Drive is one of the most efficient set ups I've seen for 2 X Li-Ion's and a 445, but with the higher voltage demand of the PL520, your run time between charges will be less is all. (for regulation)

If your host will fit 3 X Li-Ion's, it would also be just fine for that diode. Little excess voltage but not a problem for that driver...

 

[norbyx]

Well finally you have your solution. Now we want to see that laser going. When is the host expected for delivery?

 

[scumbagatheist]

Surely, you didn't miss this...

This will suffice until I get the new driver. I was right to trust my instinct. The weight just isn't what it should be without both batteries in it.

 

[Garoq]

I'm a little late to this conversation but I managed a semi-successful build in an S4 host using our SD-2 driver set at about 275mA, using two RCR123A batteries. Optical output with two different diodes was 80-90mW using a standard 3-element lens. However, the diodes in both builds failed after a relatively short time. Anyone else have this problem?