I could start designing my USB Bus-Powered Programmable Power Supply right away, but I should at least give myself some guidelines for this thing.
Output Voltage: My thought is that I need to have an 0.5-4V output voltage range at a minimum. This should cover battery powered testing for Zinc Air batteries (0.9V) up to rechargeable Lithium (3.7V). It’d be nice to get up to 5V to cover designs with three alkaline batteries (4.5V) or USB. During the design process, I’d also like to keep in mind the possibility of having a population option for the board that might make a 10V output possible. This would add 9V battery testing along with being similar to a lot of other data acquisition products that have an output range of 10V.
Output Current: If I use all 500mA provided by USB, I assume that a 300mA output current is feasible. Of course, more is better here. USB 3.0 would give me more output current, but that might be a model for the future.
Voltage Accuracy: Many power supplies are only accurate to the 0.1V, so that accuracy level is a must. Thinking about this more, 5V with a 10 bit converter gives a step size of ~5mV, so I think a good goal is an accuracy of 10mV.
Temperature Range: At a minimum, I should go for a 0-40 C temperature range. There’ll be a few parts that may see a lot of power dissipation, so that’s something I’ll have to keep an eye on.
Protection: Short circuit protection is a must. It’d be nice to have some level of overvoltage protection, but I’m not sure how feasible that is.
Programmable Current Limit: This is a common feature in power supplies, but I’m going to put this down as a maybe. I’m thinking PCB population option at this point.
Update Rate: Programmable power supplies generally have slow update rates, so my first thought is to make this a lower priority. My feeling is that the design would get too complicated if I have to start buffering output values to make waveforms.
Current Measurement: Most power supplies can give the user a coarse measurement of the current output, but I don’t think it’s a necessary feature for a low cost device. Perhaps a feature like this could be done as a population option.
Isolation: For a low cost device, isolation isn’t really feasible. In my experience designing low power devices, a device like this having isolation wouldn’t really make a difference.
Price: My target price is a $99 sale price. From experience in the test/measurement industry, a 4x markup is fairly standard, which would mean that the cost for all the parts involved should be around $25. Let’s give this an annual sales quantity around 1000, just to help with this target.
Size: Obviously, smaller would be better, but there may be a balancing act depending on the temperature rise of the components. I also assume that I’d be using an off the shelf plastic case with holes drilled out. I’m imagining screw terminals sticking out of the case. My goal here is a size similar to NI’s USB products.
LEDs: I like the idea of having an LED just to let you know the device is plugged in. If possible, maybe there’ll be an LED letting you know that device has been programmed with an output voltage and maybe an LED that indicates a fault.
So that’s my first pass at some specifications for this device. Do these specifications hit a number of things that you might need? I’d like to know if you have any other thoughts here.
I happen to have spent most of my career working on low power devices. (The only devices I’ve ever designed that exceeded 200mA is a USB device and a much less interesting version of the Clapper that could switch 10A.) Last year, I was working in an underfunded division of one of the Twin Cities’ many medical device companies. Now, I’m kind of used to having some decent test equipment at my disposal, and this group didn’t even have a benchtop power supply. As it so happened, I needed to do some testing on a device and I thought it would be great to have a programmable power supply and then I could test at different battery voltages and the like. Of course, I couldn’t even get one of those from another group. (There was at least one, but it was in use for other stuff.)
It then hit me that it would be nice to have a USB Bus-Powered Programmable Power Supply. Such a device would be cheap and small and should be able to provide more than enough power for the low power electronics I work on.
I did a lot of searching for such a device, but couldn’t find one at all. I guess I’m a little surprised no one’s made one of these before. For companies like National Instruments or DataQ, there probably just isn’t a high enough quantity compared to regular data acquisition cards.
Also, the obvious downside for something like this is that you’re limited on the amount of power you can provide. For USB 2.0, you get 5V/500mA, which is a miniscule amount of power compared to other benchtop power supplies. I think the lowest power output I’ve seen on a benchtop power supply is 30W. So a device like this would probably restrict the market to people that work on low power or battery-powered devices (like me).
So why not design it myself? I don’t really know what the market is for this idea, but I think it would be fun to design it. I thought I’d open up the design and we can all learn together about designing something like this. Along the way, I’m going to be using as many free/low cost tools as possible, so that’ll be new for me.
I think it’d be great to find out that others want a device like this or maybe some variant. And during this process, comments will always be welcome.
I was at the recent IEEE Banquet here in the Twin Cities and I happened to meet someone who had an idea for a product and offered equity positions to people that could help out. Several of us listened to the pitch, but we were all (more than) a little wary. Afterward, I took a few minutes to look at this person’s company and patent. I was surprised to see a full patent had been issued a few years ago and filed several years before that. Additionally, one of the local patent law firms wrote the patent.
For some of you out there, I thought I’d give some of my thoughts on paying for patents as a small entrepreneur. A friend of mine is a registered patent agent (Let’s call him PA here) so basically everything I know about patents comes either from him or from my own meager experiences filing a few patents. Let’s outline what PA and I came up with for my own situation, which is somewhat similar to my new acquaintance from IEEE. This situation is geared towards people without a lot of funding.
So I have an idea for a product. Now, the strategy is not to go out and patent it as soon as you come up with the idea. You have to work on it and figure out how you’re going to implement this idea and then along the way list all of the possible variations (i.e. embodiments) to this idea. And you work and work and work and finally your product is ready for sale, but right before then, you file your provisional patent.
What’s a provisional patent? PA describes it as giving your engineering notebook to the USPTO and then within a year you can file a real patent. However, disclosures made in the provisional patent are enforceable from the day you file the provisional. And a provisional patent only costs $110.
Why file the provisional before sale? In case you don’t know, you can’t file patents on things that are public knowledge. (I’m guessing there’s a more legalese way of expressing that.) And then you have a year to sell your product and then if you make money, you can file your patent. (You’d have the money for that now.) If the product is a complete failure, you’re only out that $110.
For my own situation, PA suggested that I file the patent “Pro se”, which means that I’d basically write and file the patent on my own, but I’d get his assistance for free. (PA warned me that I might get what I pay for.) Obviously, this is a much cheaper option, I think it’s something that should be considered especially if you have a few patents under your belt.
Hopefully, the entrepreneur I spoke to does find someone to do the development work, but maybe on their next idea, they might reverse the process and do some of that work first before going after the patent.
I was at our local LabVIEW User Group meeting and the main presentation was from a National Instruments Engineer on Object Oriented Programming. I thought the presentation was very good and to paraphrase one of the other attendees, this was the only time I’ve discussed Object Oriented and LabVIEW and left thinking that I need to explore this more.
I’m not a computer programmer by training so a lot of the OO concepts are somewhat new to me, but here it was presented more like a glorified cluster. And then with this cluster, you can designate VIs that go with those clusters. In the presentation, the concept just seemed to be so much simpler than I first thought (as I guess usually happens in these kinds of demonstrations).
I think I’ll start off looking at the Othello example from the contest earlier this year. And then I’ll look a little into the Hardware Abstraction Layer stuff, but that will be the topic for a future LUG meeting.
A while back, I had some testing to do at work and found a specific sensor to help with that. As it turns out, this sensor could only be interfaced with I2C and I didn’t have any equipment for interfacing to that. Like I’ve said before, I’m a LabVIEW guy and so I went to ni.com and checked out the USB-8451. This device is a USB device that can interface to I2C, SPI, SMBus and additional DIO. It’s also $400 and interfacing random I2C sensors isn’t something I do on a regular basis so I thought I’d look for a cheaper solution that I could still control through LabVIEW.
In past jobs, I’ve used USB ICs from FTDI so I looked through their website and I found the FT2232H. Along with the normal UART functionality, this chip can also communicate through synchronous serial protocols (I2C, SPI, JTAG). It comes in an evaluation module that I found on Digikey and Mouser for only $27 so that seemed like a pretty good deal. And the FTDI website has one LabVIEW example for interfacing I2C.
So did it work? Yeah, but it took over a day to get everything working, though that was more because of the sensor I was working with and not the I2C product. But I’d call it a wash between the two products. However, I took some time to learn how the FTDI program worked and now I’m comfortable writing DLL calls in LabVIEW so that’s a nice bonus.
It’d have been nice though if the FTDI example followed all of the LabVIEW conventions. I redid all of their functions for error bars, icons, and things like that. But $400 vs. $27 is a pretty big difference and these cheaper modules can be a good alternative depending on your situation. And if I need to add USB to a design I’m working on, this will definitely be an option.
Recently, I was at my local National Instruments Technical Symposium. I happened upon a conversation where a few guys were discussing having your LabVIEW program e-mail you so I thought that might be a good post idea. I’ve done this a couple times: once with a POP mail server and once with Gmail. I really have no idea how to do this, but fortunately, the NI website/forums have several examples on this.
I tried doing POP first and for some reason, my IT guy at the time insisted on making a specific e-mail for my LabVIEW program. Not a big deal, but in retrospect, I probably shouldn’t have even told him about it until I knew exactly what I wanted. I only did this kind of long term testing a couple times anyway.
The Gmail stuff I found very easy. I simplified the code in the example and had no problems at all.
We also discussed having LabVIEW text you. I think the easy solution here is to use your cell phone’s e-mail address. I’ve never done this with LabVIEW, but e-mailing to a phone works just fine.
I’ll do some more posting on NITS coming up.
A post for the test engineers that I hope will be my customers/readers some day
A while back, I needed to buy a DMM for work. I needed at least 6 digits for the kind of tests I would be doing. Also, I like being able to program my test equipment, so computer connectivity was another requirement. Third, this would also be used by a few coworkers who have laptops, so having USB for the computer connection is a strong preference. Also, I figure that it’s 2010 and I shouldn’t have to deal with USB to RS232 or GPIB converters if I don’t have to.
With these requirements, I came up with three products:
Now, that’s a pretty big difference between 1300 and 862. Of course, the Keithley isn’t as accurate as the Agilent, so that’s understandable. However, the NI device isn’t as accurate as the Agilent either. I’m a LabVIEW guy so I contacted NI to see if I was missing something here. All they could do was point out the size factor and easy LabVIEW programming. To me, to program any of these devices would be pretty easy, so that part’s not valuable to me. The size factor and the fact that the 4065 is powered only through USB I’m sure makes for a more difficult design compared to the other two. But the final thing for me was that the Keithley was available used. In the end Keithley wins this round, but if accuracy had been more important, I probably would have chosen the Agilent.
I recently became aware of Signametrics SMU2055 USB DMM, which also looks intriguing. I still think I would’ve gone with Keithley just because some of my coworkers are more likely to use the DMM as a standalone device.
Any thoughts on this? You can e-mail me at email@example.com
I had my second meeting with my MEDA business counselor this week. There’s so much to think about. One of the questions he asked me was “How many people will be working for you 3-5 years from now?” In my head, I’m thinking, “I can barely imagine the scenario where I’m quitting my job let alone hiring other people.”
But he asked me to dream so I said 20 people. I kinda pulled that number out of the air, but it seemed logical. Let’s say 10 people for R&D with engineers and a couple technicians in that mix. A few manufacturing technicians and then marketing, support, and G&A and that comes out to about 20 I think.
Then he goes through the math. In this scenario, I’d probably be looking at 2 million a year just to make payroll. Wow. That would be a lot of devices. (I’m looking at making/selling low cost test devices.) But, and I know I’ve said this already, but it’s really good to talk about the long term with someone. Someday, this company will be more than just me and I have to continually remind myself of that.
I submitted a LabVIEW idea the other day and if you can, could you give it a kudos? I’m happy to say that I’ve already received 7 kudos. I tried voting for myself, but it doesn’t let you.
So the idea is to have LabVIEW give you the option of making watermark decorations. This came up a while back and I was making some new test software that I wanted to send around to a small group of internal users. I added big bold text that said “BETA” to make sure no one actually used it for real. I thought it would’ve been nice though to have a nice watermark that’s always in the corner.
I’ve written a program in the past that had an image follow a window around and LabVIEW evaluation software has a big NI logo watermark on that so I assume this can’t be that difficult.
Here’s the link again.
I went to my first LabVIEW User Group meeting yesterday. Jed, one of the NI sales reps (and the rep for my company), mentioned that the Oklahoma LUG gets 140 people every time. Wow. We had a more modest ~25, but there were 3 Certified LabVIEW Architects there along with a certified Instructor. I’m only a Certified LabVIEW Associate Developer (CLAD) and that’s only because they were offering the test for free a while back.
Mostly though, Jed and Craig (another local NI sales rep) discussed new hardware released at NIWeek a few months ago and the newest version of LabVIEW. It’s funny though that a feature like the new booleans so impresses this group of people.
I know there were other features discussed, but for me at least, this is the one that I’ll remember and is the one I actually discussed with a few people at the meeting.
Anyway, if you’re a LabVIEW programmer or just a test engineer of some sort, I would suggest attending these meetings. Good networking and some good content too.
One of the first things MEDA was able to do was to set me up with lawyers. So recently, I met with two law students at the University of Minnesota Law School and their supervising attorney, who has practiced patent law for about five years now. They were all very eager to help me in any way.
There’s one catch to my free legal advice and it’s the first thing we discussed, which is a form I signed that gives them permission to discuss my case in class. I can’t imagine them talking about my business as nothing’s happened yet. Really, I hope they never talk about me in class because that likely means something really weird happened and I’d prefer that all of my legal matters go smoothly.
As I mentioned before, I actually haven’t set up my business yet, but one of the first things the students did is volunteer to draft up my Articles of Organization. FYI, this is the form that sets up a limited liability corporation (LLC). If you actually look at the form, you would see that it’s only two pages, so I definitely could have done it myself. I had planned to, but if they need the practice, then they can do it.
They also volunteered to write a membership agreement. I actually had no idea what that was and also thought, “Why do I need one if I’m the only employee?” But it sounds like a good idea for the future when there are employees and investors and the like.
They’re also going to draft up a confidentiality agreement. Now, I’ve signed and had people sign one several times and I was just going to copy one I’ve used in the past. They said some lawyers do that, but of course, they advise against it. I kinda feel skeptical about confidentiality agreements just because I feel like a large company could pretty much do what they want and I’d need a whole team of lawyers to fight it, but at least this’d be something, right?
Mostly though, we talked about patents. I’ll talk about that in a later post.
We’ll start with some entrepreneurial posts as that’s what currently takes up most of my time.
As I said earlier, I’m Filipino. I also happen to live in the Twin Cities in Minnesota, so there’ll be a number of posts that might be local to the area.
Minnesota has several organizations dedicated to helping local entrepreneurs, but the one I’ve found the most helpful so far is called MEDA (Metropolitan Economic Development Association). This group focuses on helping minority entrepreneurs. As I’m working primarily on my own, it’s nice to have someone looking over my shoulder.
I had my first meeting with them just last week. I wasn’t really sure what to expect, but I ended up talking for almost two hours with my business counselor. He’s definitely a good match for me as he has an engineering degree and an MBA. He’s really pushing me to think beyond the first few months, which I think will be good to think of that stuff now.
But he gave me some homework which I’ll tell you a little about here:
FYI, My business counselor isn’t really familiar with catalogs and I plan on selling my device through catalog distributors, hence the need for #4.
Doing marketing analysis is strange for me as I’ve never done any marketing work in my career. I feel like my “conservative” estimates may not actually be “conservative”, but I justify this in my head by thinking that these are always estimates, right?
My counselor really wanted to know how I see the future so that he can work backwards from that while I work forwards.
I’m sure I’ll be meeting with MEDA again in the future, but to those entrepreneurs working on their own, having someone to mentor you is a nice thing to have.
Hello. My name is PulidoGuy and I am the founder of a company called Pulido Technologies. Actually, I haven’t founded the company yet, but I’m very close to setting up all of that. Sorry, but I’m not using my real name just yet (Pulido is not my real name). I’m still currently employed and I don’t plan on telling anyone at my current company what I’m up to just yet. But just like most of us, I’m tantalized by the idea of quitting my job and working for myself.
Why is the company called Pulido? Well, Pulido is a last name used by relatives several generations ago. I’m Filipino and Pulido happens to mean polished in Tagalog. I liked the sound of that. In addition, variants like pulidotechnologies was available as a website. And lastly, I felt like Pulido would be reasonably easy for people to spell. And as I’m not entirely positive the company will always be doing what I currently have in mind, I wanted something a little general just in case.
What is the company? I plan on manufacturing a test device for electrical engineers and test engineers. I used to work at a major test/measurement company. According to people in the know on patents, I’m not supposed to divulge the nature of this device in a public forum. But if we meet, I’d freely discuss it with you. I may have to push a non-disclosure, but I’m not sure yet.
As we go along, I’ll be posting on topics that hardware engineers and test engineers might find interesting. I’m a hardware designer and a LabVIEW programmer so that’s likely to be the main focus for my technical posts. I’ll also be posting on my adventures as hopeful entrepreneur. I hope this makes for some enjoyable reading.