SF-AW210 quick question

I just finished my first 6x BR and I've just got one question. When I tested the driver I built for it with my test load I used 7 1N4001 diodes becuase that gave me a 4.9V drop and the SF-AW210 gives a 4.8V drop. Anyway, I was using the lm317 driver like I have many times before so nothing new there. I used a 9V battery as well like usual. So for this driver I used 4.4 ohms of resistance for my fixed resistor value which I calculated would give me 284.1mV, therefore 284.1mA of drive current. When I tested it though I got a reading of 240mV. My real question here is, would using a dummy load that gave slightly more of a voltage drop be the cause of this reading? or did I just do some math wrong?

Thanks
Blaine

Probably but ask one of the veteran members if you want to know for sure.

First off is this correct...
1) you have all 7x 1N400x diodes in series with a 1ohm resistor (anode towards neg).
2) are you reading your current in parallel with the 1ohm resistor?

Also how did you come up with that figure? (what equation did you use).

Well if you set up the dummy load correctly you shouldn't really have that much trouble, if measured correctly. BTW 7x 1N400x are considered the "norm" in dummy loads for a 6x, so again... shouldn't have problems there.

When I tested it though I got a reading of 240mV

Click to expand...

How did you test it? with the dummy load on?


~~~My thoughts.... I think you know what your talking about/doing, probably a maths error.. remember to carry the one ~~~

Yep all that's correct. All the diodes are in series with the resistor, test with dummy load on, and so on. I used the math equations from Rog8811s site again lol. That's the only reason I wasn't sure that it was just a math error. Now I'm only human so I know it is still possible that I made a mistake, but I can't seem to find it if I did LOL. That's why I posted to see if someone else might be able to tell me if/where I may have messed up.

Thanks
Blaine

I have two ideas for this:
1. Your 9v battery isn't providing enough voltage. Try using more voltage to get your desired current.
2. The 9v battery might not be able to handle the 280mA of current. Try using different batteries.
Oh, and you might want to turn the current down a little.. These diodes are a bit inconsistent as I have one going at 160mA and it has degraded after a few months.

Aha. Well I thought the batteries voltage may have been an issue too but it was putting out 9.36v. I think it may just be that it can't handle the current like you said, I've got some 3.6v cr123a batteries coming in the mail soon so I'm hoping those will be able to handle the current.

And thanks for the heads up btw.

Thanks
Blaine

have the batteries come yet? if not you can try connecting the battery straight to the dummy load, check the voltage & current.... that might answer ur questions.. I did this today, on my mxdl host battery holder, and found that the voltage was too low atm to run my laser... so I guess you can check if the current or voltage drops when its under load.

Jimmymcjimthejim said:

Oh, and you might want to turn the current down a little.. These diodes are a bit inconsistent as I have one going at 160mA and it has degraded after a few months.

Click to expand...

Yeah 280mA is very high. Most do not push GGW's past 200mA and the GGW is a much better diode.

if not you can try connecting the battery straight to the dummy load, check the voltage & current.... that might answer ur questions.. I did this today, on my mxdl host battery holder, and found that the voltage was too low atm to run my laser... so I guess you can check if the current or voltage drops when its under load.

Click to expand...

Awesome I never thought of that lol but it makes sense. Thanks bob.

As far as the current goes...poop lol. I guess I'll just need to turn it down

I guess I could just use it like that till it goes out then just get another one concidering they aren't TOO expensive, but $30 is up there atm for me at least lol. Thanks for your advice though guys it's helped me out. Ill have to go check out what kind of current my battery can handle untill I get the new batts. They should be here in about a week or so.

Thanks
Blaine

Np... happy to help