Lava Micro FlexDrive Driver (lavadrive2) fits pens

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Ok then.Would an IR diode from a CDROM work as a dummy load? Even though it's probably gonna die at that current.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

No! You DO need to connect the driver-GND to battery-GND on at least one side, either the input or the output! Or both! But at least on one side!

Click to expand...

Ooooh! So the driver GND isn't all useless and can be bypassed. Yea.So theeen, basically only my first diagram is wrong.I hope I got it right now. :-/

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Argh. Sorry for the sloppy formulation
Of course I know that It is a constant current source and I know that you can not set the voltage with a flexdrive.
Why didn´t you just say, yes, It would xD
But thanks anyway ;D

Going to use 2 CR123a primaries with a silicon diode.
So the Voltage would be 5.7 at very full charge,
and 4.7 with nearly empty batterys, right?
The flexdrive can handle upto 6V.

ArRaY

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Switch said:

Ok then.Would an IR diode from a CDROM work as a dummy load? Even though it's probably gonna die at that current.

Click to expand...

No, it wouldn't work.. An IR diode has a forward voltage of <2V.. The FlexDrive can't regulate the current if the output voltage is under 2.7V. That's because the current sensing IC on it is powered by the driver output and needs at least 2.7V to work. If the driver output is under 2.7V, the current sensing IC stops working, and the driver dumps a shit load of current through the load.

So in order to drive loads with a Vf of under 2V, you need to add a Si diode or two, to increase the combined Vf above 2V. This of course decreases the efficiency of the setup, due to power lost on the Si diode. But for testing that doesn't really matter..


You can just solder some Si diodes in series (just make sure their combined Vf is between 2.7-6V). I use a CREE LED and three diodes in series with it, to test my driver. But the three diodes in series were a bit too much for the FlexDrive, as it came close to, or above 6V and started blinking, especially since it was powered by my switching PSU at that time (the FlexDrive doesn't like my PSU). CREE and two Si diodes were a good approximation of a PHR tho.

Of course, when the driver works as it is supposed to, the actual Vf of the dummy doesn't have to be anywhere near the actual load's Vf, it just has to be in range.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Switch said:

Ooooh! So the driver GND isn't all useless and can be bypassed. Yea.So theeen, basically only my first diagram is wrong.I hope I got it right now. :-/

Click to expand...

Hehe, no, driver-GNDs are usually not that useless, and can't just be bypassed..

It has to be connected to the battery-GND somewhere. It's just the where, that doesn't matter, as the driver GND is the same on the input and the output side. Metal hosts just give more connection options.
You can use the diode to feed the battery-GND to the driver. With reds this happens as soon as you solder the two wires between the diode and the driver, and then the driver only needs the battery-positive connection. With the PHR you can achieve the same by simply shorting the diode-negative to diode-can, if diode is well grounded to the host.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

got mines today cant wait to test it with my diode when it arrives.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Wow it's a lot smaller than I thought It's REALLY small !!

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

ArRaY said:

Argh. Sorry for the sloppy formulation
Of course I know that It is a constant current source and I know that you can not set the voltage with a flexdrive.
Why didn´t you just say, yes, It would xD
But thanks anyway  ;D

Going to use 2 CR123a primaries with a silicon diode.
So the Voltage would be 5.7 at very full charge,
and 4.7 with nearly empty batterys, right?
The flexdrive can handle upto 6V.

Click to expand...

Oh, sorry.. i get it now. You were asking that if you set the current when the battery voltage is 5V, will it remain the same, when the battery voltage drops to 2.7V. In that case, yes, it will.

I must have misread the "set the current at 5V" for "set the current to 5V".  :-[ But i have an excuse.. I'm half blind at the moment..  : And bored for the same reason, so i came here, altho i should be resting my eyes..


If you use 3V Lithium primaries, they will discharge much lower, than 4.7V and the driver will still work just fine. Since they are one use only, you can drain them to 1.2V each, before the driver stops.

If you use the green 3V rechargable Lithiums, they should not be discharged bellow 2V each tho. This can be problematic, as you would not see a decrease in performance till the batteries were permanently damaged. That's why one protected Li-Ion is a PERFECT power supply for drivers like these, as it is in the perfect range and automatically cuts off, before getting damaged. It can't have too much nor too little voltage.

With one Li-Ion, the efficiency of the system will also be at max, while you are wasting some power as heat, when you use 6V and an Si diode - the efficiency of the system becomes lower.


As far as i know, there are rechargable Li-Ion batteries in the exact shape and size of two CR123s on top of each other. That would be a much better solution. Fits in the same host, works at max efficiency and auto cuts off, before damaging the battery.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Nah, it is great that you are always helpful!
May I ask what happend to your eyes? I read that you had a surgery....

Rechargable and protected CR123A won´t fit my sonar II barrel...
So I have cr123a primarys on the way to my home. I don´t know any other battery that will fit there,
that is why I have to suffer the loss in efficiency. Dr. Lava said something like from 85-90% with a single one to 70-80% with two.

However, If they had like 1000mAh each, and I would set the flexdrive to 135 mA, that would be like 6,2h runtime for each pair of batterys. I think that is pretty decent.

ArRaY

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Big thanks to IgorT for explaining the connections on this driver! kudos.

So you guys get it now, right..

Don't use an IR diode as a dummy load, use 4 diodes and a 1 ohm shunt resistor as a test load, or a red laser diode as it says in the instructions. The IR diode most likely has a voltage drop below 2V.

Also as IgorT said, when you are load testing, use a battery and short leads as the supply.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

[quote ]Rechargable and protected CR123A won´t fit my sonar II barrel...
So I have cr123a primarys on the way to my home. I don´t know any other battery that will fit there,
that is why I have to suffer the loss in efficiency. Dr. Lava said something like from 85-90% with a single one to 70-80% with two.[/quote]

I'm using 17670s in my sonars.  had to remove the wrapper to make them fit, but they are perfect, no drop diode necessary.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

How do you isolate them? If you remove the wrapping, don´t they have a massive metal body? If it is negative, no problem.
Also, are they rechargable and protected ? or not protected?

ArRaY

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

ArRaY said:

Nah, it is great that you are always helpful!
May I ask what happend to your eyes? I read that you had a surgery....

Rechargable and protected CR123A won´t fit my sonar II barrel...
So I have cr123a primarys on the way to my home. I don´t know any other battery that will fit there,
that is why I have to suffer the loss in efficiency. Dr. Lava said something like from 85-90% with a single one to 70-80% with two.

However, If they had like 1000mAh each, and I would set the flexdrive to 135 mA, that would be like 6,2h runtime for each pair of batterys. I think that is pretty decent.

Click to expand...

Yeah, the run time is decent. I'm just obsessed about perfection sometimes and i prefer rechargables. Never mind me..


I did not have surgery no. I woke up with a bloody and painful eye last Friday. Actually the pain woke me up. At first i tried to tough it out and work, but it got worse, till i was rushed to the ER in the evening. I was examined for a whopping 20 seconds, and given the wrong medicine, and woke up blind! All fog. First i thought it's just the cream i got, but next day i still didn't see crap, so i went back to the ER. Then to a proper eye doctor, who's been giving me daily injections straight into my eye! I thought that only happens in horror movies or psyberpunk novels.

The good news is, the injections help. The bad news is, the more they help, the better i can see them! :'( Luckily, i think today was the last one. I can almost see again!


Be careful with your eyes, people! And no, it wasn't lasers in my case.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

Yeah, the run time is decent. I'm just obsessed about perfection sometimes and i prefer rechargables. Never mind me..


I did not have surgery no. I woke up with a bloody and painful eye last Friday. Actually the pain woke me up. At first i tried to tough it out and work, but it got worse, till i was rushed to the ER in the evening. I was examined for a whopping 20 seconds, and given the wrong medicine, and woke up blind! All fog. First i thought it's just the cream i got, but next day i still didn't see crap, so i went back to the ER. Then to a proper eye doctor, who's been giving me daily injections straight into my eye! I thought that only happens in horror movies or psyberpunk novels.

The good news is, the injections help. The bad news is, the more they help, the better i can see them!  :'( Luckily, i think today was the last one. I can almost see again!


Be careful with your eyes, people! And no, it wasn't lasers in my case.


That was what I feard. But I think there would have been a bigger discussion about it ;D
Great to hear it is getting better. Usually, I am a perfectionist, too. But as long as I don´t have an alternative, except the 17670, but I need further information on them.

/me

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

ArRaY said:

How do you isolate them? If you remove the wrapping, don´t they have a massive metal body? If it is negative, no problem.
Also, are they rechargable and protected ? or not protected?

ArRaY

Click to expand...

Yep, the body is negative, so it's no problem until you install it backwards.. !!. I re-wrapped mine with clear scotch tape which is thinner than the shrinkwrap they used and it fits still. Loading unwrapped silver cells feels almost like loading rounds into the laser

Igort, is this glaucoma related or..? WOW sorry to hear, I hope it comes back to normal for you.

Re: Lava Micro FlexDrive Driver (lavadrive2) fits

drlava said:

Loading unwrapped silver cells feels almost like loading rounds into the laser

Click to expand...

I can imagine that! Somehow reminds me of someone on this forum, who told a girl lasers get loaded with destilled rainbows ;D

Are they from DX? protected, unprotected?

/me