Re: The Elasti-drive Intro (V1 and V2)
Thanks
And I don't mean to sound like an insistent child, but when can we expect fixed or solder_your_resisters_yourself versions of this driver?
PM LeQuack if you want a driver now. He isn't really set up for mass production right now, but we do want some of these in use for testing. If he can't do it, I'll see what I can do... But I don't plan on doing any real selling or manufacturing.
We are looking into a reseller solution, but we want to keep costs down. That has been a major factor in this project. Very early on we decided that our GOAL was to create a driver that was smaller, better and cheaper than the flex.
This was not out of any ill will toward Dr. Lava, but out of frustration with his frequent absences and the higher price of the flex.
To be fair to the good doctor, we have certainly learned that there is a reason that there aren't a dozen alternatives to the flex. The flex is a good driver. But that just made the target we were aiming for all that much more enticing.
Are we there yet? Arguably yes and arguably no.
We don't have the adjustment capabilities yet, that has presented us with new and unexpected challenges. But our fixed output versions are shaping up to be available in two flavors.
1. Small and affordable.
2. Very small and still a good bit less than the flex.
And both of those drivers have some features that I don't believe the flex offers.
Here are the features we currently are starting to implement on all new PCBs going forward. (These are not available yet, we only have the slightly larger early revisions available at this point, but the newer versions are on order.)
1. By request, centered output pads;
2. Optional 8.85 mm by 11.33 mm - fits in a module; or 9 mm x 11.7 mm;
3. Continuous negative/ground;
4. Thermal protection that WORKS, I've encountered it several times;
5. Heatsink pad on PCB - we may be able sell it sinked;
6. Over voltage protection;
7. Under voltage protection for batteries;
8. Takes a wide variety if inputs from 2.5v-12v in;
9. Output up to 8v - no worry about 405's or 9mm blues not getting enough V;
10. Can be paralleled;
11. Reverse polarity protection. (We could go smaller without this, but I personally feel very strongly about reverse protection. If you could control what these drivers were going in, you could take it out and have a smaller driver with lower part count and lower cost, because you could design your laser pointer to physically protect you from reverse polarity. But it just sucks to fry a laser because of a common and simple oversight. I grew up in an age where you put batteries in something and if it didn't work, you turned them around and it did work.
And we are at $15.99 for the larger of the two (which isn't MUCH larger) and should be under $20 (I think) for the super micro model. (When you start trying to buy good caps at the edge of the limits for uF/size they start to go from nickels and dimes to quarters and dollars real fast.)
Another feature that we haven't mentioned, and this may vary over time - but I am anal retentive about parts specs. I drove Jared crazy always trying to find a better capacitor or a better resistor for the driver. There is always a point where you say, "Whoah, we can't put $0.50 X8R caps on this board when we can get $0.05 X7R caps!" or I would have to settle for 10% caps when I wanted 5% because of cost, but that was rare. In many, many instances - we ended up with very good materials.
I concentrated very hard on trying to go X7R or better, and if I chose an X5R product, it was by absolute necessity. And X5R isn't bad, but I aimed higher. Same for resistors, I shot for 25ppm/°C where possible and I don't think there is anything worse than 100ppm/°C on the board, other than the pot which doesn't matter so much.
But I tried my hardest to find parts that would take HEAT and not just stay alive, but KEEP WORKING under the conditions.
Now I'll be very upfront and say that part of my motivation was to give us parts for protoyping that would not be giving us problems so we could focus on the driver design rather than wondering if a budget capacitor was the problem. But we have a lot of those parts still in the bins and it will be hundreds of drivers from now before we have to re-analyze and see I'd we could save money with less expensive parts or if it would be worth it. For the foreseeable future, these drives are going to be built from premium components!
So there you have it right now.
We have a board that works. We have smaller versions of that board on the way. The new ones will feature centered output pads and hopefully usable heatsink pads. Our adjustable version is still under construction.
So what is next? Well, Jared and I need to decide on distribution. He's in college and I have a full time gig. Does he bake a bunch of popular currents and send them to Clif or someone to sell?
Does he try to run a shop out of his dorm room?
Those are the questions we face right now.
For the short term, we would like to get some boards in people's hands, and I would be willing to make a FEW if he wants to go that route. We will talk it over and get back to everyone.
In the meantime, post your desired values and applications please...
500mA, 525mA, 550mA? What do you have in mind?
:thanks:
) and today isn't looking great either. 
