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Alx's LD CURRENT DRIVER (30mA-800mA/5V-16V)


New member
Jan 8, 2009
6.63USD - LD CURRENT DRIVER (30mA-800mA/5V-16V)

This post has been updated on 22 June 2009. Read below and look to see first row in blue color! Paypal Accepted too!!

As I said in one of my past post here:


My intention wasn't to reinvent the whell. All I wanted is just to build a small driver at resonable price. I collected information about existing current drivers residing on LPF and build one which probably, will better fit our needs.
I also, keeped the price as low as possible.

In benefit of LPF community, I am ready to release it now.

- build using SMD components (similar with those using LMxxx regulator)
- output: adjustable, 30mA up to 800mA
- input voltage: minimum 5V - maximum 16V (2 x 3.7V LI-ION will be ok)
- reverse polarity protection (schottky protection)
- voltage oscillation protection (using capacitors)
- allow you to connect/solder directly your LD on to the PCB
- fit inside DX/Aixiz module (tested)

Some notes:
- my intention was to release it more than 6 weeks ago. When almost finished (testing process) and ready to release it (30mA up to 450mA), I realized that I can do it better and changed specs again. This caused another delay (testing varying smd components, redesign PCB, long negotiations with SMD manufacturers/suppliers in order to obtain better rates, spent more money, etc).

- shortly, the PCB has been redesigned and ordered only qualified components for higher currents rates (up to 1A).

After tests, I concluded that this goal can be achieved using an unified PCB version but with small changes regarding SMD components as following:

First one:
- designed circuit for: 30mA up to 840mA
Due to tolerance of some SMD components, this version will really work:
- from 30mA up to around 700mA (almost all PCBs) - recommended use!
- up to 740mA - 760mA (valid for more than 50% of them)
- and finally 780mA or more - just few of them

Second one:
- designed circuit for: 105mA up to 1040mA
- recommended use: from 0.7A up to 1A (in order to not overload some components)
- adjustable too, but here, the sensitivity will be a little bit lower at UPPER RANGE (we are operating with fractions of resistance, under 1 Ohm - for example we can have 0.1 Ohm for dozens of mA)

At this time, the second one will not be considered a priority, because in most cases, we are operating under 500mA. At rates over 0.7A, duty cycles and heat disipation, should be taken in consideration more. I have no doubt that will work (because all components has been choosen/tested very carrefully and are heat resistant) but, should be tested more.
Also, some of sourface mount components used here are more expensive than those used in first case. Anyway, for those which want to test it, i can build few and keep the price the same like for first one!

About price:

As i said, my intention is to offer this driver at lower rates (as much as possible)!

[update info on 22 June 2009]

Promotion: Starting from today, I am offering this driver at rates available only for bigger orders (over 100pcs/order)!

Super Sale: 6.63USD/driver shipped everywhere using M2!

30 drivers/order at only 199USD - assembled, tested, tracked, insured! Payments accepted via Paypal!

Buy it today and have it shipped next business day!

This promotion will end at 5 July 2009!

[end update - 22 June 2009]

[update info on 20 May 2009]
Proposed schema (all drivers will be assembled and tested before shipping):

Non EU orders:

MOQ.....Price/item(USD).....Shipping cost.....Price/Item (Delivered to you, incl Shipping/Tracking/Insurance)
100...............6.................25(using M2).........6.25
50.................7.................25(using M2).........7.5
30.................8.................25(using M2)........8.8-8.9
20.................9.................25(using M2).........9.25

So, here, you can get it at 6.2-6.3USD/driver - assembled, tested, shipped, tracked, insured!!!

EU Orders:

MOQ.....Price/item(USD).....Shipping cost.....Price/Item (Delivered to you, incl Shipping/Tracking/Insurance)
100 ...............7.2.................25(using M2).......................7.45
50..................7.8.................25(using M2)........................8.3
30..................8.4.................25(using M2)......................9.2-9.3
20...................9.................. 25(using M2)......................10.25
<20................10..................5 or 25 (using M1 or M2)....11.25-12.5

And, here, you can get it at 7.4-7.5USD/driver - assembled, tested, shipped, tracked, insured!!!

As I said, is a proposed schema. All I want is to make it accesible to anyone, keeping the minimum order quantity (MOQ) and price very low.
Will not be any presales or Group Buy. I will support all costs required to produce this driver, in order to deliver very small quantities at very low amount of money (max order will be around 600USD for only 100pcs).

What I am planning is to do all things here, to produce it, and ship it to few poples (our forum members) in small quantities (let say under 100pcs each per order), AT LOWER RATES AS POSSIBLE.
Al I want is to have/find some RELIABLE PEOPLES, which can spread this driver to our community using local shipping rates (better than international rates and faster). THAT IS MY CONTRIBUTION AND I WILL STOP HERE. So, in this case, other peoples should take care about retail segment (of course, continuing to keep price as low is possible). I don't want/need some greedy peoples which will speculate the price!

All I need is some peoples which comes near me, join to this project and sustain just a little my efforts!

For the NEXT WEEK OR NEXT 2 WEEKS, has been scheduled the following tasks:
- announcement about proposed schema regarding price/discounts/products in order to see, who will be willing to join and how we can do, in order to better serve all of us!
- I will expect emails to: XELLA71@GRAD.COM from all peoples which want to join this project, containg their proposals, ideas, intended/needed quatities, etc.
- All correspondence will be private, and at the end, when all things will be cleared, I will post here the agreed results.
One thing I want to mention: If will not be enough interest for this project (ordered quatities, unreliable peoples, etc), I won't go ahead!
As you can see, almost 95% has been already done by me. All you need is just small ammount of money (few hundred dollars), some time and maybe a little altruism. Greedy peoples will not be wellcome!
Note: if you tried to contact me at xella71@grad.com and not receive my reply within next 24 hours, it mean that I not received your message. In this case, drop me a private message here!

My feeling is telling that most customers are located in USA, so I'm expecting that more than 60% of total sales to goes in this direction. Also I want to mention that Euros is very stronger and USD continue to fall down. Due to this reason I increased a little the price for EU customers. I did not take yet the final decision, but could be a way to sustain this project alive for everybody! If EU orders will be bigger than USA orders, I will lower the EU price too.

Regarding shipping method (M1 - 5USD)
- I shipped 3 drivers (free of charge) to 3 of our members, on 27th April 2009: 1 goes in Canada and 2 in USA. All 3 users, confirmed that received the driver!
- the package has been delivered direct in their mailbox, even sent registered, with customer signature. It take 4 days to cross continents and another 5 up to 10 days to be delivered (inside USA) to the destination. USPS proved to be unpredictable (for one customer, misrouted the package to a wrong destination which added other 5 days delay)!

Conclusion: M1 is not as reliable as I expect/want. So, this method WILL BE AVAILABE ONLY FOR EU CUSTOMERS (delivery time: around 3 days - tested)!

Regarding shipping method (M2 - 25USD):
- reliable, to any destinations
- tested (i sent goods to China and arrived at destination in only 8 days)
- tracked & insured
- online tracking number
- customs declaration

So, M2 will be the one which we can use in the future (around 25 USD/order - all included: shipping cost, tracking, insurance, etc)

About payment:
- Paypal accepted! Today (22 June 2009), I passed the last step verification at paypal (for full account). So, from today, Paypal become the first accepted payment method.

- Moneygram.com (cheap & fast)
Use this link to calculate fees in order to send money:
MoneyGram Pricing Input - USA
Note: In some circumstances, Moneygram seems to be better even than paypal (with no restrictions on your side and lower fees).

- Western Union (expensive than moneygram, fast too)
Western Union – Money Transfer – Quick Collect – Send Money Online - Telegram - Send Cash

- Bank Wire (slower, and probably less expensive than Western Union but expensive than Moneygram. I will be able to receive money after minimum 3 days you sent it

The rest of info below, remain valid!
[end update - 20 May 2009]

Better rates can be achieved if we are talking about quantities. And this, due to SMD manufacturers/supplyers conditions, assembly line costs and other restrictions (to many, which not worth to be mentioned here)!

I did not take a decision yet, about producing it at large scale. Is a project which require more money and i'm not convinced that it worth this investment. We will see in the future if we can have it at lower rates. Now, we have it at 10USD and trust me, all my work till now, cost me enough to make a lot of other peoples to give up and run out of money. But now, we are here and going ahead! I think for now, 10USD is a fair price to start to test the market and satisfy our needs.

It will be delivered only ASSEMBLED and ready to use! NO KITS AVAILABLE! If some of inside components are defective, or if not soldered/manipulated correctly, will be/become unusable. So, i think that assembled and pre-tested driver will be the best option for us, even for me it mean more work! Will protect booth sides about future discussions claiming a defective component or driver!

So, all drivers will be ASSEMBLED AND TESTED before shipping (I am testing at 110mA using one phr diode). After tests, all capacitors will be discharged, so, the driver will be safe and ready to use!

About international shipping:

Method 1

Ship as small correspondence - Priority Mail (Flat) - cheapest method

- all over the world: 5USD
- insurance: some and limited - see my note below
- estimated delivery time: 3 working days inside EU, minim 6 working days outside EU
- registered (with track & trace and customer signature)
- limited to max 4 drivers/shipment

Insurance - Priority Mail (Flat)
For most EU destinations:
- included by default - up to 45USD/order
- values over 45USD/shipment, support upgrade to desired "declared value - DV"
which will add a small fee/shipment: 0.8% * (DV-45).

Please note that insurance and "declared value - DV" option is ACCEPTABLE FOR MOST OF EU COUNTRIES BUT WILL NOT BE AVAILABLE FOR UK CUSTOMERS!

For NON EU destinations (USA/CANADA) and also UK:
- no insurance
- no "declared value - DV" option available

Here, exist just a value which may vary from one country to another which will be reinbursed by postal service if the package is lost or damaged in transit. All i know is that this value will be decided after investigations (it can take up to 3 months) and cannot exceed few times the postage fees! It will not work if the package is held by customs!

For other destinations (non mentioned above) please ask!

If no insurance or limited insurance is available (not covering all shipment value), I will limit orders to max 4 drivers/shipment and will ship at your own risk! If you want to be fully covered, use Method 2 below!

Track & Trace - Priority Mail (Flat)
Tracking number will be available.
It can be traced online:
- near source - my country
- near destination - your country.
Does it mean that you cannot trace it on all its way like UPS/FEDEX/DHL shipments.

For this shipping method, still remain unclear some details (about postage restrictions, customs declarations, insurance). I hope to be clarified after first few NON EU orders!

Some hints (unofficially):
- I was informed that in USA, flat correspondence even has been sent with customer signature, is possible to be delivered direct to your mailbox like regular mail!!!
- I heard that international correspondence coming/going to Australia is possible to arrive opend (opend by Australian authorities)!

Method 2

Ship as small package - Priority Mail (Package) - moderate price

- al over the world: around 20USD - destination dependent (correct for most destinations)!
- insurance: will be included anyway, but for additional charge (0.8% * DV).
Does it mean that I'll not ship without insurance!
- estimated delivery time: 3 working days inside EU, minim 6 working days outside EU
- registered (with track & trace - same as above - and customer signature)
- will be charged for a minimum weight of 1KG anyway
- you can order as many drivers you wish. you are limited just by the weight
(1 driver = max 2 grams -> will be max 500 drivers/shipment at this price)

- one packet with weight under 1KG
- shipping cost: 20USD
- declared value: 250USD
- insurance: 2USD (0.008*250USD)
Total order: 22USD (tracked & insured) + 250USD (goods) = 272USD


Please note that importing goods can mean that your national customs authorities may charge you customs duties and/or other additional related taxes (Value Added Tax, Purchase Tax, etc). You (as the importer), are responsible for paying any such taxes. If you do not know how much (if any) import tax will be, please check with your local tax authorities before ordering.

Some countries prohibit or restrict the importation of some types of goods. You may need a general or special license and/or other documents to import goods, particularly in larger or commercial quantities. It is your responsibility to check with your national customs authorities whether the goods you intend to import are subject to any such restrictions. If your goods are retained or confiscated by your own national customs authorities for any reason, it is your responsibility to negotiate with them the terms on which such goods might be released to you.

Shortly: I will not be responsible and I can't help you if the package will be held by customs and is in your duty to pay all (customs) tax (if will be some).

- Paypal accepted starting with 22 June 2009!
- Paypal fees already included in driver+shipping cost, so will not be a complicated formula as I saw others peoples are asking customers to use.
- Moneygram
- Western Union
- Bank Wire

Final Notes:

- My intention is to ship all collected orders one time/week (on each Monday).
Anyway, if I'll have time, is possible to ship sooner than each Monday!

- Any shipping method you choose from above, you will know when your item has been shipped out. Also, you can estimate when will be there and check online at your national postal service to see if already arrived! Please note, that in some circumstances, online tracking at your side, may not work or may not be updated or infrequent updated. In this case, check your mailbox for a notification coming from your local post office!

Last edited:


Dec 13, 2007
By the looks of the layout, there is not much heatsinking.. How long do your drivers run at anything over 400mA before the thermal protection kicks in?

I use the same version of the lm317 in mine, with much more copper, and they have a hard time driving a 6x @ 220mA for longer than 30 seconds before the mA's begin to fall off.

The heat issue becomes even more of an problem with LOC's over 400mA, and inside the rear cap will be passing all of the heat onto the LD..

Your saying .8 amp???


New member
Mar 31, 2009
WannaBurn said:
By the looks of the layout, there is not much heatsinking.. How long do your drivers run at anything over 400mA before the thermal protection kicks in?

I use the same version of the lm317 in mine, with much more copper, and they have a hard time driving a 6x @ 220mA for longer than 30 seconds before the mA's begin to fall off.

The heat issue becomes even more of an problem with LOC's over 400mA, and inside the rear cap will be passing all of the heat onto the LD..

Your saying .8 amp???
could be me but it looks like an LM117


New member
Jan 8, 2009
WannaBurn said:
By the looks of the layout, there is not much heatsinking.. How long do your drivers run at anything over 400mA before the thermal protection kicks in?

I use the same version of the lm317 in mine, with much more copper, and they have a hard time driving a 6x @ 220mA for longer than 30 seconds before the mA's begin to fall off.

The heat issue becomes even more of an problem with LOC's over 400mA, and inside the rear cap will be passing all of the heat onto the LD..

Your saying .8 amp???
I don't know what driver are you using, but anyhow, in my case, i am running my red laser diode at 420mA and no problems. I am using duty cycles 60secs on/off, due to red laser diode restrictions (LPC-815) and not due to the driver's restrictions. Anyway, at higher rates, heat can be a problem and this driver (as its size) connot run as is (even better components inside) without heatsink. Part of heat, will be dissipated in AX/Dx case (used as heatsink). Also, as higher rates and SMALL size, duty cycles BECOME A MUST. Also, you can use more external heatsinks... to help it. Intelligence may be with you Luke... but remember, it can't be just small and work for a long time or without duty cycles! Do you want a bigger one? I found some on thorlabs.com (support up to 4A, but looks like a brick) :) and cost thousands dollars! The size is a problem, no doubt, but you should choose:
- small & cheap? some restrictions
- bigger? could be cheap or expensive, depending by your choice!
So, we need to help a little such a small one driver. And more than that, we want to be ADJUSTABLE, to fit iside AX/Dx module!

That's I said that second one should be tested more! You didn't read carefully my post. I redesigned the driver to support higher currents (new SONY red diodes/500mW require over 700mA). I does not mean that we need it now at 0.7A!!! We can use it for LPC (0.4A) and PHR (0.11A) without problems!

For now, NOBODY here need such higher currents.

Anyway, you can order one driver and test it! But remember, i am not willing te spent more time here on forum, answering questions regarding second one try, which can be available only on demand and ONLY ON LIMITED QUANTITIES, for those which has more time than me for testing! Trust me: it can't be cheap, small (fit inside AX/DX) and powerfull ... without some restrictions!



Well-known member
Nov 22, 2008
Hi, what's the dropoff voltage on these? (the voltage needed at supply subtract the max voltage at output)? Also, if you need a hand setting up an online shop to simplify ordering, feel free to PM me.