Micro FlexDrive jumpers

[goosesensor]

Hey Guys. :wave:

I'm trying to configure my flexdrive for about 1.4 amps.

I can't seem to get it above 1...

The jumpers are set such that they are all connected. Like this: http://goosesensor.net/flex.png

I have a new AW 10180 that I charged for about 1-2 hours reading at just above 4 volts.

This is the second time/flexdrive I've had this problem with... (I accidentally broke the pot off the first :cryyy

Am I doing something wrong?

Thanks!

 

[goosesensor]

I should also mention that my test circuit consists of 6 1N4001 diodes and a 1W 1Ohm resister.

 

[goosesensor]

Looks like I have the wrong diodes. I have 1N4003 not 1N4001.

 

[bluuray]

i dont know if you can use 4001 diodes to measure current over 1A
and that battery cant handle that much current.. oO

 

[Wolfman29]

Hey, can't 1N4004 diodes handle 3A?

 

[goosesensor]

Everywhere I see says 1A...

 

[Eudaimonium]

Rectifier diodes of 1n400x series (that's from 4001 to 4007) are rated for a maximum current of 1 Ampere. Difference is that 4001 can only take 50V while 4007 can take IIRC 1kV of voltage.

So you need rectifiers from 1n530x series, at least I think, I believe FlaminPyro sells high amperate test loads around here (up to 3A).

Also, would you mind telling us what sort of power supply are you using to power your driver? Perhaps it cannot deliver the current it needs.

 

[goosesensor]

My power source is a 3900mw 10180 battery.

The 1N4003 appear to be fine in terms of heat/current if I only leave them connected for <10 seconds at a time, I'm just not sure how many of them to use.

If I hook up a AA batt to a multimeter, measure the voltage, and then short it with a single 1N4003, the voltage drops by .55 volts. So I figured, 8 * .55 = 4.4V, perfect.

No.

With 6 diodes I can turn the pot and adjust from about .5 volts to about 1 volt at the resister on the test load. If I add another one or two diodes to the test load (for a total of 7 or 8) my readings across the resister just stick at about .07 volts and never change no matter where the pot is. So strange.

I think I'll just go get some 1N4001's from Radio Shack. But, I'm curious to find out what's going on, so if anybody has any ideas, shoot!

 

[LtKernelPanic]

GAH! I had a nice reply written and the friggin forums wen't down for 'upgrade' again.

Anyhow...

For my 3A test load I used 1N5404 diodes. You can get them cheap at Digikey or Mouser. If you just need the diodes you can get them in a 2 pack for like 89 cents (which is highway robbery but still cheaper than paying shipping for a few diodes) at rat shack if you don't have a local electronics parts store. I'd use a 1 Ohm resistor in the 5-10W range but as an FYI drlava has recommended not using wire wound resistors in test loads since they can damage the driver.

 

[Eudaimonium]

@goosesensor ... Your power supply is what battery, now? 10180? Not possible, also battery capacity is measured in mili-ampere-hours, (mAh), not mW, so not sure what are you talking about there.

Also, you apparently do not understand what we're trying to say to you. It's not about adding more diodes, man. If you add more diodes, FlexDrive has a more difficult work of boosting the voltage. Your average 445nm diode has a voltage drop of around 4.5 V at 1A of current, so Flex needs to use those 4.2 or less volts from battery, and more current drawn from it, to convert it into missing voltage - it's what boost drivers do.

So if you want your 1A at 4.5V from one lithium ion battery, battery draw could be anywhere between 1.2 and 1.5A depending on current setup conditions: battery wear, capacity, quality, driver temperature and efficiency, diode temperature and efficiency.

Why don't you take a picture of that battery of yours so we can see what this is on about? Perhaps you are even doing everything right, but your battery is too weak to supply needed current you want.

EDIT @ LtKernelPanic - When you write a reply, click post and get the "Upgrading" message, don't hit back or go anywhere else, simply keep hitting refresh. Your browser will ask you do you want to submit the same data you did as before (which is your forum's post message), so hitting refresh is exactly as hitting the "Post" button with your post written in the box. Keep refreshing until the upgrade time is over and you get a sucessfull post. Works every time

 

[Jufran88]

Wow, a 10180 lithium battery? It's about 1/3 a AAA battery in size so that's pretty small. If you have enough space for what ever your building you might want a bigger battery, because judging at that size it will be around 100 - 300 mAh which will not last long if your drawing 1.5A from it.

For your test load, if your setting up a boost drive, like the micro flexdrive, you want to use 4 diodes (1N540X series for higher currents)

 

[bluuray]

^^^^^ he has a good test load , for a really good price.. and it could be used for other wavelenghts too

 

[goosesensor]

*2900mA, and my bad, I totally got the battery mixed up... -> AW 18650 Protected 2900 mAh Rechargeable Lithium Battery

I'm just full of misinformation, aren't I?

@ jufran

I've got about 8 1N5406's here. Should I stick four of them together?
PS. That is indeed a sexy test load.

 

[Jufran88]

Ah, ok so your using an 18650 battery.

For future reference:
mA = milli amp = electrical current
mAh = milli amp hour = electrical charge for batteries

Yes, use 4 diodes in series with your 1 ohm resistor to set the current on your flex drive.

PS: :thanks: for the comment about my test loads!

 

[goosesensor]

@ Jufran

Got it. Makes sense, thanks.

@ All

Thank you for helping an obvious noob. :bowdown:

Now if I can just get my girlfriend to leave (we're at her parents') I can finish by build! :gun:

 

[goosesensor]

Thanks for the help everybody. I'm now lasin' :drool: