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FrozenGate by Avery

Introducing two new miniature drivers for portable lasers

Re: Introducing two new miniature drivers for portable lasers + Kenom Fundraiser!

yobresal said:
Exactly! and no I have not checked the Vf at diode. What are some high and low Vf readings you've taken on 12X diodes? I am wondering if it is possible that this diode could just have an especially high Vf.
Click to expand...

Maybe. I had one that was approaching 7V at the diode. I will have to search up the records, but I was NOT at as high a current as you are running here (IIRC it was ~500mA).

At 7V at the diode, it would take in excess of 8.2V for the driver to regulate the current correctly.

Peace,
dave
 





Re: Introducing two new miniature drivers for portable lasers + Kenom Fundraiser!

Hey Dr. Lava, I just ordered a couple of the new drivers and was curious when I could be expecting them to be shipped. I'm in no rush, I was just curious so I don't get to anxious ;)
 
Re: Introducing two new miniature drivers for portable lasers + Kenom Fundraiser!

daguin said:
Maybe. I had one that was approaching 7V at the diode. I will have to search up the records, but I was NOT at as high a current as you are running here (IIRC it was ~500mA).

At 7V at the diode, it would take in excess of 8.2V for the driver to regulate the current correctly.

Peace,
dave
Click to expand...

Well that is probably what is going on then. I am not too worried about it because even if the current drops down to 500mA 0r 450mA by the time the batteries need to recharge I am still going to be pumping out >600mW. It will be good for the longevity of the diode.
 
Re: Introducing two new miniature drivers for portable lasers + Kenom Fundraiser!

I should be getting my micro boost any day now.

HMike
 
drlava, I have noticed that the new Micro BoostDrive actually uses extra current even though it does not have to boost voltage...

I realize that it is for 'boost only' applications. But the new 445 diode takes high current and is very close to a single Li-Ion 18650 in forward voltage.

Anyway, I was hoping to understand it is all...

I love the driver. And it is very stable. The pot is very nice for adjusting as well. :)

Here is an example of readings I just took with my 445 build:

* 445nm A130 projector diode
* Lens used - AixiZ 405 glass
* 640mA's
* 530mW's
* Forward voltage - 4.03
* Battery current draw using a Micro BoostDriver and AW 18650 - 812mA's

This driver is using extra current even though it is not having to boost voltage...

That said, it is a very stable driver. Just trying to understand it better...

Could my battery be sagging in voltage that much right off the bat? (yes, fully charged)
 
Hi Jay, thanks for the compliments on the MicroBoost driver. I've been really happy with it, too. For best efficiency, the manual says to use the highest range possible that still includes your desired current. For 640mA, this would be to set all 3 jumpers. (note, you can solder to the top pad of the resistor to the right of the small range resistors in the diagram)

After doing this, I get:

4.16V in, 720mA in
4.07V out 640mA out

for an efficiency of about 86.6%

If you do have all 3 range jumpers set, then yes it's likely your battery voltage is sagging a lot.

One thing I should note is that you want to be really careful not to have the output voltage less than VBatt-350mV. As this is a boost driver, it cannot buck battery voltage that is very much above the load voltage. Running above this limit risks over-current on the load. For example you DONT want to drive a 4V diode with the microboost and a 5V supply.
 
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Thanks for the explanation...

I have it set in the 390 - 750 range. So maybe I should have set it to the 540 - 1000 range and it would have better efficiency at 640mA's setting.

I do realize that it is a boost only driver. In my 445 build, the diode is asking for 4.03 volts at 640mA's.

The driver seems very stable even though my battery starts out at slightly more voltage. (4.2)

Of course at the high current draw, the battery surely sags in voltage immediately...

Should be just fine wouldn't you say?
 
Yep, it should be just fine. If the battery were 4.4V then that would be a different story, but as luck would have it things work out perfectly for this combination. Also, you can do slightly better than the 540-1000 mA range which only has two jumpers set, by setting all 3 in a combination of the 390-750 range and 210-410 range.
 
Very interesting...

Thanks!

Awesome driver! ( I just ordered another 10) :)
 
So the microboost has an absolute max of 1A? So if I want I can just skip using a test load, turn it all the way up, and connect it to my 445nm diode and it'll run at 1A?
I don't have a multimeter at the moment is why I ask. My friend is gonna bring his on saturday but if I get my driver before then I don't think I can wait :p lol
 
Like the FlexDrive, it has a 'single turn' pot. (a nicer one though) :)

You can damage the pot if you turn it too far in either direction. Maybe not, but it's not supposed to be turned past a certain point in either direction...

So you must jumper the range setting, and then use a test load with your DMM to set the current properly...
 
jayrob said:
Like the FlexDrive, it has a 'single turn' pot. (a nicer one though) :)

You can damage the pot if you turn it too far in either direction. Maybe not, but it's not supposed to be turned past a certain point in either direction...

So you must jumper the range setting, and then use a test load with your DMM to set the current properly...
Click to expand...
Hmm, perhaps I could just set it in the high range and not mess with the pot?
Then I wouldn't risk breaking it, and I could adjust it to my desired current later when I have access to a multimeter.
 
Have you set a FlexDrive or a Micro BoostDrive before?

Just asking because when you set the current, you always want to disconnect your diode, and use a test load.

The pot on the new Micro BoostDrive is much nicer for adjustment, but disconnecting your diode and using a test load is still the only safe and proper way to adjust current...

In case you have not already seen it, rog8811 wrote a nice article on drivers and adjusting current with a test load.

He shows a DDL driver, but it is the same procedure with a FlexDrive or Micro BoostDrive:
It can be done - Laser driver
 
jayrob said:
Have you set a FlexDrive or a Micro BoostDrive before?

Just asking because when you set the current, you always want to disconnect your diode, and use a test load.

The pot on the new Micro BoostDrive is much nicer for adjustment, but disconnecting your diode and using a test load is still the only safe and proper way to adjust current...

In case you have not already seen it, rog8811 wrote a nice article on drivers and adjusting current with a test load.

He shows a DDL driver, but it is the same procedure with a FlexDrive or Micro BoostDrive:
It can be done - Laser driver
Click to expand...
Yes I've used flex's many times :p I don't see how this could be unsafe at all though?
What I was getting at is that since the driver is 1A max, and these diodes can take that and more, I couldn't possibly harm the diode by connecting my microboost without actually setting the current.
Of course, like I said, I would later set the current with a test load as soon as I can :p But in the meantime, I want this 445nm to LIVE regardless of the power :p
 
The 1A max range actually can go higher than 1A output if you turn the pot all the way up. it's headroom so that it can at least make 1000 mA including manufacturing variations. Just use a dummy load and multimeter.

The pot on the groove2 and MicroBoost has stops that won't allow it to be turned further than each end, unless you really force it.
 
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