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Re: How do I set the power for the FlexDrive using

Bionic-Badger

Bionic-Badger

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Re: How do I set the power for the FlexDrive using

Make sure it is hooked to something (laser diode, test load, etc.), and then I think you can measure the voltage over one of the 0.1ohm resistors. Dr. Lava should have an instruction manual for it.
 





Re: How do I set the power for the FlexDrive using

If you don't even know how to use your DMM, you probably ought to read some guides first and practice on something else. You're liable to break something otherwise. You can find Dr. Lava's Lavadrive manual on the net. I'm not quite sure if the version you have has that tiny resistor to measure on, but you can use your own resistor for that.

For your battery problem, you ought to have a simple power source of some kind that you can use to power the driver while you set it. I would not try holding the battery to the connector to do it. For myself, I use a simple modified breadboard power supply.
 
Re: How do I set the power for the FlexDrive using

Kloan, this is why I offer a 'Hot' option with my kits...

Especially with such a tiny build as the Micro Chrome! The smaller the build, the harder it is.

As mentioned in my thread, you must set the current before mounting the driver into the pill. One way that this can be done, is to use a wire.

I don't recommend adjusting current with your LD connected. You must have a proper test load. Such as a rkcstr test load. The FlexDrive can have some very touchy spots in the adjustment and could jump around too much. (IMO) Better to use a test load, and then connect your LD afterward. And just to be extra safe, touch the leads together after you set the current in case there may be some voltage 'charged' in the driver. (in a cap or something)

Wire method:
Pinch one end of the wire to the side of the brass ring on the tiny circuit board with one hand. And with the other hand, hold the other end of the wire to the negative end of the battery. Make sure all other connections with your test load and DMM are correct, and touch the positive end of the battery to the contact point on the tiny round circuit board to check the reading.

You would have to use 'trial and error' testing and adjusting for this method and this tiny build. Then, after you get it where you want it, it is important to re-check current after you install it into the tiny pill.

Seems kind of stone age, but it can be done very effectively if you have sure hands, and you understand how the connections need to be for the test load and DMM...

If you have a test load, you can follow this diagram by rog8811 for the DMM connections. He shows a home made test load with a DDL driver, but the connections for the meter are the same:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197651171#1

Once again, the main thing that makes it difficult, is the size of the build! And I warn in my thread that this is a very tight build.

I hope it works out for you, because it is a superb little host! :)
Jay
 
Re: How do I set the power for the FlexDrive using

PHR?

There may be a way to check the current safely with the LD connected, but I only use the same method with a test load every time... So I know no other. Here's the documentation for the FlexDrive:
http://hacylon.case.edu/ebay/laser_diode/MicroFlexDrive User Manual.pdf

It also depends on which jumpers you have soldered. These little boost circuits are complex little drivers. I still recommend de-soldering the diode. If you load the tip of your soldering iron with a little solder first, you can just 'touch' it to the pin and the wire would come off in less than a 1/2 second.

But I don't want to talk you into doing something that ends up leading to a dead diode either! ;D So I hope you get it complete. Because it sure is a nice little host huh?
Jay
 
Re: How do I set the power for the FlexDrive using

Yes, but the pot can be damaged by turning it too far. That's another reason for having a test load and being able to watch the current as you make adjustments, or very little 'trial and error' adjustments in some cases...
Jay
 
Re: How do I set the power for the FlexDrive using

I don't think you should be trying to test current on the FlexDrive without a proper test load. You may kill your diode as well as your driver!

Have you studied the diagram from rog8811 that I linked?
Jay
 
Re: How do I set the power for the FlexDrive using

You can't use the diode to check the current. You need to measure over the resistor. Use Ohm's law to determine how much current is flowing through the resistor:

Current = Voltage / Resistance

The voltage will be what you measure across the resistor (a DMM lead on either side of the resistor).
 
Re: How do I set the power for the FlexDrive using

Man at this point, if you insist on not doing it properly, then your best option is to power the diode and carefully turn the pot until it gets to the brightest.

Do this with a light touch. You should feel a very slight resistance at the end of the adjustment. It is a single turn pot. So you will only be turning it about 1/2 turn form the position that it came in.

But don't blame me if something bad happens. In this case, it is better than you probing around the driver with your DMM...

Since your driver is in the stock 'lowest' range. You should not be able to get much more than about 100mA's.
Jay
 
Re: How do I set the power for the FlexDrive using

Well I had to say that because I recommended something that is NOT recommended. ;D

Anyway, accroding to the FlexDrive instruction sheet, you would need to solder a jumper across two tiny resistors to get into a range above 100mA's... (3rd diagram is the easiest)
Jay
 

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Re: How do I set the power for the FlexDrive using

Well, Harbor Freight does sell some pretty "cheap" (with all the connotations) equipment, but even their $5 multimeters can still do the job.

But nevermind, it looks like you've given the hobby up.
 
Re: How do I set the power for the FlexDrive using

This is quite basic and I am feeling generous, so I present to you, on a silver platter, how to set your flexdrive with a DMM.

Make a test load from 3 or 4 1N400x series diodes (4001, 4004, 4007 etc all work) and a small value resistor, all in series. Ideally you will get a high tolerance 1 ohm resistor but you can use anything on hand. I only had 10 ohm resistors so I put some in parallel until I had 3 ohms.

Measure the resistance of the resistor and write it down for later, unless it is exactly 1 ohm. Connect the test load to the flexdrive - solder it so it doesn't accidentally disconnect while you're measuring. The stripe on the diodes goes to the negative terminal on the flexdrive.

Use ohms law to find the current through the resistor with the formula I = V/R. If your resistor is 1 ohm, it is easy because 1mV = 1mA. If your resistor was say 2 ohms, divide the measured voltage by 2 to get the current.

Likewise, if you want to set your flexdrive to say 150mA and you have a 0.5 ohm resistor, the voltage you need to be measuring with the DMM is V = I*R; = 150 * 0.5 = 75mV
 
Re: How do I set the power for the FlexDrive using

Kloan said:
[quote author=Bionic-Badger link=1239418681/0#19 date=1239434751]Well, Harbor Freight does sell some pretty "cheap" (with all the connotations) equipment, but even their $5 multimeters can still do the job.

But nevermind, it looks like you've given the hobby up.
Click to expand...
I planned on selling everything anyway, since I spent way too much frickin money on all this stuff... I would've been better off just buying one, but I like building things. [highlight]I wasn't expecting to be so frustrated trying to get some advice.[/highlight][/quote]

The advice was given..... but it was not taken... ::)

No knowledgeable member here would risk testing the output of a FlexDrive
using a Laser Diode (especially a Blu-Ray) unless they had a lot of cheap spare LDs...

You asked how to drive a Stick Shift Vehicle and were told how to... but you don't
want to use the Clutch.... Sorry.... can't help you any further... Good luck... 8-)

Jerry
 
Re: How do I set the power for the FlexDrive using

Kloan said:
Looks like no one here knows how to do that!
Click to expand...

I will tell you exactly how to do it. Put your DMM on current measuring mode and put it in series with your diode.

I will also tell you that if you disconnect this circuit with the power on, your flexdrive will fry. If you accidentally increase the current too high (easy to do on those sensetive flexdrive pots) your laser diode will fry.


USE A TEST LOAD
 
Re: How do I set the power for the FlexDrive using

Not sure why removing the diode and getting a rkcstr test load to test the Flexdrive is so difficult. Why you would want to make it more complex is beyond me. If you are half-way decent at soldering (which is sounds like you are), you should be able to remove the soldered connection of the diode and driver easily, then just use a appropriate test load to set the flexdrive, then just connect it back up again.

I can understand your frustration as I am also starting to learn the whole building process of these things, and it does in fact get very VERY frustrating at times... but don't just give up so easily, especially when the solution is so simple.


De-solder the diode pins, remove it, buy a rkcstr test load (when they get back in stock) connect it to a flexdrive, set the current and use the mV selection on your MM on the test load pins (in which 1 mV =1 mA) then solder the pins back onto the flexdrive and your ready to go.
 
Re: How do I set the power for the FlexDrive using

Yes...

We all remember when we first learned. Building these red and blu-ray lasers are actually very easy to do ONCE you go through the learning process.

But most will kill a diode or two learning. At first, it can be very frustrating. Even after you learn how to do everything, you can still make a simple mistake once in a while. I have killed a $300 dollar diode with a dumb mistake. (more than once!) ;D

That can be very frustrating...
Jay

P.S. I honestly tried to give my best advise for the situation. Sorry it didn't work out...
 
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