Re: Micro-Drive laser driver – fits Aixiz module
[size=+2]Updates and Information[/size]
06/27/2009:
Everything is at the assembler and getting close to being done! Should be finished somewhere around 6/29 to 7/6, then a few days to ship to me and then shipped to you!
06/05/2009:
Status so far is I have prices on assembly, I'm just waiting on the PCBs and parts, which I should have by next week. At that point, they get shipped to the assembler and they should be done in 2-3 weeks after that. I'm hoping to have them by the end of this month.
06/02/2009:
I decided to start up the presale while I wait to get confirmation of assembly prices. You can check out
this post to get the details.
06/01/2009:
I'm finalizing prices for my assembled drivers (still waiting on hearing back on one thing). I will probably start the presale in the next couple days using my new prices (plus extra discount!). The pre-sale will be for
assembled drivers only. Any other items (kits/parts) will be available when I start selling items regularly again (sometime after June 15th).
Check
this post for information on what my revised offerings will include.
05/09/2009:
The manufacturer has contacted me and is working on a quote for assembly of the drivers. Once I have a cost, I will revise my current prices. If the cost is reasonably low, then I will likely lower prices. I don't expect the cost for assembly to be very high, so in all likelihood, I WILL lower prices! No word yet on when I may have any more available for sale, but I'm trying to make them available ASAP. Also, once I get assembly arranged and in process, I will probably be holding a "pre-sale" to cover costs, but selling them with a PRE-SALE DISCOUNT! Keep your eyes open for that
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*IMPORTANT: Aixiz Module Size Variances:[/size]
It has been brought to my attention that recently Aixiz modules have not been as accurately (or should I say consistently) manufactured. Some have said that their modules were shorter than usual and my driver did not fit properly. So, if you already have your module, before you buy, make some measurements to see if it's a regular size. A standard module will have the back portion (the part that screws onto the "head" that holds the diode), should be about 22mm (mine have measured 22.5mm), and the threaded portion on the head should be 3mm. If you back portion is shorter, you can still use the drivers, but you may have to modify the driver board or the module to fit it properly.
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International Shipping: [/size]
I quote the standard international shipping as 2-3 weeks, but the US Post Office doesn't give a time frame for any country, so that may be inaccurate. The good news is that, I've heard from some members that they've received their items in a week. So, you may receive your items in 1-2 weeks in actuality, rather than 2-3 weeks. But, that's only a possibility, if you definitely want them faster, you can pay more for the Expedited (6-10 days), Express (3-5 days) or Express Air (1-3 days).
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Extra output value settings:[/size]
A request by someone on the forum spawned this idea. Typically, I only offer the values specified in my first post, as you know. But, if you need a slightly different value, it's possible for a little adjustment between the normal values of 38-400mA by using the 33 ohm resistors I use for the blu-ray in combination with the others. There is actually a large amount of values possible, so this link below is a spreadsheet with all of the values and other information. Most people probably won't need anything that specific, but they are available. Also, as a note, my standard values aren't exact, they can vary by a few mA (except the 38mA, it's exactly 37.7mA), as you can see in the document:
http://spreadsheets.google.com/ccc?key=pW49OuYfRMm4-k6TaQk0BZw&hl=en
You will need a Google account to view the files above. Or, alternatively, you can download the Microsoft Excel file here:
http://rkcstr.googlepages.com/OutputSettings.xls
Also, to note... other (ie higher) output values are possible by either adding more parallel resistors or different values. It's possible to stack more resistors on top of the four, but that's not recommended by me, so feel free to order extra resistors and DIY.
[size=+1]IMPORTANT WARNING (for old drivers, pre Oct '08):[/size]
When connecting your driver to a power source, it is CRITICAL that you connect the leads to the proper polarity!!
[If you ordered as of 6/12/08, a better protection has been implemented and there is less concern for this problem, though you should always take care to make the correct connections!]
I've had some troubles recently with driver malfuction after reversing polarity, which for the most part, I know people are careful enough to not do that, but if you do, it may possibly damage the regulator chip on there causing it to put out TOO MUCH current to your diode and possibly damaging it.
This mainly comes from my own mistake in reversing the power leads on a module I made up... ended up blowing the diode when the chip put out 1A into it
Now, some may say, "hey, there's a reverse-protection diode on there, what gives??" This was originally implemented because mostly because of requests to be like Daedel's circuit, which uses the same design. But, what this effectively does is it creates a short across the diode when the polarity is reversed, which means you're shorting the regulator IC. This WILL protect the diode, but if you damage the driver, causing it to put out too much current, when you go to power it up the CORRECT way, it will kill your diode.
So, what I suggest is that if you think you've reversed polarity, to TEST the driver before powering up your laser diode again. This means disconnecting the diode from the driver and hooking up a test load to make sure it's putting out the proper current.
What does this all mean to you? Not much, if you follow directions, lol ;D Just make sure you don't switch the input wires around....
WHITE IS POSITIVE, BLACK IS NEGATIVE
I'm currently looking into implementing a better protection using a MOSFET (credit goes to Colin, AKA cdanjo), which should effectively break the circuit entirely in the case of a polarity reversal. I'll also be including a reminder warning with all of the drivers I sent out.
38mA and 50mA drivers ordered before 5/13/2008:
As mentioned in this thread and in an email that was sent to all those who would be affected, I have found that the low output drivers tend to put out below spec current. There is no danger to damaging your laser diode, it just may not be driven by as much current as you expect. There is a simple fix which involves adding a small capacitor to the board. This can be done by me or yourself if you feel this is a problem, but for most, this really isn't a big deal. The perceived and actual difference between the output of the two drivers is really minimal (actual output may be around 32mA for the 38mA drivers). But, again, if this is a problem you wish to be resolved, you may contact me and we will figure something out.
