July 26, 2016
January 30, 2013
In about a months time, I will start to publish some of my designs for charging the Li-Ion batteries using USB on pc's or chargers.
June 05, 2011
I have shown the original work in progress version, that I posted in my previous post, to Chu Moy at Headwize, that created the CMoy, and was happy to see it and encouraged me to post in head-fi. I hope others will appreciate and like these variations too.
Now, I will explain a little bit the circuit. I researched for about a week for the most suitable diodes that would suit this design. The main objective was to have the lowest Vf @ 100 mA. Well, I thought it would be an easy task, it tourned out to be extremely time consuming.
I ended up with the SB220/240 (not the SB120/140) series in my original design. Now when you are on fire, and your design is not 100% finalised, ideas still tend to creep in to your head, ok even after 100%, there is always something you are not happy with. I had found the SR series by luck on the internet, until then I knew the Germanium diodes were better... for lower Vf. Well that is true, up to a point ;-) they are great in crystal radios for one reason., VERY LOW I or mA say, can someone say 1 mA and under?... yep! when I started viewing their datasheets, I was amazed at how low the Vf was, until I seen finally the charts for Vf against I. Then they did not seem nice!
Your best 'run of the mill' diode that you can find everywhere, is the 1n5817/8/9. Its Vf is: typical/maximum at 0.1A (100 mA) is ~0.28 / 0.34 for the 1N5819. I did start with the 1N5817, since I was looking at only one doubling stage with a '9v' Li-Ion 600mA battery. Then I added the other stages and safety margins and ended up with the 40v parts.
The SR and SB series are from Won-Top Electronics Co., Ltd., a Taiwanese manufacturer. Their products are available from Digi-Key and others, but I got some SR-140 from eBay due to the postage rates that Digi-Key charges on international orders. I w aould have loved to use the SB240, and yes I know they have free shipping at Digikey, but only for orders of $200 or more. Maybe another time.
As a side note, the SR sereies has been replaced by the SB series.
Now as to my comments previously about lasting at least 10 x as longer. It is simple, use 3000 mAh for NiMH batteries (AA size) or 1 x 18650 for Li-Ion at 3800 or 4000 mAh. The TC962 uses about 510µA-700µA. Lets say to make it easier, 1 mA x 4 = 4 mA, plus the LDO,
Now I do have a few other variations that include USB chaging of "Apple" devices as long as you have a USB cable to attach. A simple circuit would be the following:
Altoids Mint Tin Project - Minty Boost - USB Battery Charger. (and yes, there is also YouTube too).
This would be useful for many people. You can incorporate it in your own design and add a switch when you are to start charging.
I would recommend people to buy "Protected" Li-Ion batteries and chargers, as it will save them a lot of headache if they were unprotected and they deeply discharged.
What "protected" batteries are, is that they also contain a small circuit board inside the battery case.
It protects them from overcharge, discharge etc.
The only hard part for the 18650 is finding holders, of which are easy to find in the U.S. through Digi-Key etc. just search for 18650 battery holders. As an example here is a direct link.
Mouser has a similar policy with Digi-Key ;-)
Now, back to the design.
Capacitors, always use larger voltage ratings than what you are using.
If you are tight on space, in the 1st stage, you can use 16v, since it will not see that much, second stage, 25v and third 50v.
If you want it to look all the same, just use 50v versions. Try and find very low esr capacitors or use tantalum.
I do not have an osciloscope to check what is happening with the caps etc. I do recommend to ground pin 6 ALWAYS, so it is at 24 kHz, so it is out of the audio frequency.
Thank you for reading. I hope it has helped other people to get them thinking of designing the power section of their CMoy.
Btw, I recently came across a great page for a CMoy with Bass Boost. It can easily be altered to make an on-off switch for the BB. :-)
Here is the link to the page:
He also has schematics and all.
It is a very interesting design.
Until next time.
I will be posting a link to this blog on www.head-fi.org for more peoples opinions. Just go to the Forums section and from there to Misc.-Category Forums and then D.I.Y.
June 04, 2011
A quick post. I have found some time to play with the CMoy power stage.
I have been in contact with Chu Moy, as in the inventor of the CMoy headphone amp original design.
The design is based on using a SINGLE Li-Ion battery or two!
It will run at least 10 times longer compared to using a normal "9v" 200 mAh Ni-MH battery and also run a little more "better" due to the larger voltage available and mA too.
I aslo have a circuit that will be for charging the battery(-ies), although I have a few versions.
There is one for Li-Ion/ Li-Pol and another for LiFePO4 (LFM). The later is MUCH safer, but I am not publishing any of those just yet, due to that they require you to be able to handle QFN packages (for my prefered IC's). There are a few that are larger, and from many companies too. There are also some Chinese made, that are available in SO and DIP, but I do not like chasing down items that are hard to find.
I will present two versions for now, a simple one and a slightly more 'advanced' version with more items to buy.
As for BOM, please write them down from the schematics that I have supplied ;-) as I will not at this stage do that, maybe later.
p.s. At this pointin time, I have been unable to assemble the below schematics, but they should work AS-IS.
p.s.2 If you are to use any of these for commercial benefit, then a small royalty will be expected.
- One-OFF: only for personal use will be exempt! :-)
V6 as shown to Chu "CMoy" Moy.
This is v7. The "simple" version.
and an updated version to the above is this that gives you two options for input voltage, if under 9v use the left, if more and upto 16v the use the right input:
I will soon be publishing my slightly more advanced version thatwill be more precise and can still work when you reach the battery right down to where it shouldn't go... I will be posting this by end of Sunday here.
I have some information in the schematics for part selection. Please do NOT use 18v all the time as that is the maximum rating for the part and it can degrade after prolonged use at that voltage. A safer voltage will be 15v. That is what my next schematic includes.
It will be different, since it will only use 1 or 2 batteries either in series or parallel for Li-Ion/ Li-Pol/ LFM. You would also be able to use 3-4 Ni-MH batteries in series with my next version.
It is important to use the recomended diodes if you are using up to 9v, since when doubled, it will be just under the 18v (17.4v) if you are at exactly 9v, else you will have a much bigger drop.
WARNING: BE SURE TO READ THE SPECIFICATIONS OF YOUR OP-AMP! SOME ARE SINGLE VOLTAGE, OTHERS ARE NOT RATED UP TO 36V!!!
PROCEEDING ON IMPLEMENTING MY SCHEMATICS WILL BE AT YOUR OWN RISK!!!
If anyone wants to read up on the TC962 they can click the link or go to Microchips website. Here is a link to it on Microchips site: TC962.
November 09, 2010
Finally an update to my previous postings.
I have started constructing my clock after shelving the project for two years.
I have gone the way of modular design. What that means is, that the most important items are in modular form, or compartmentalised. Basically, every section is on its own board.
I have made a simple voltage regulator for 5v (LDO).
I have made the timing circuit on a separate board, the display, on its own board, the logic on its own.
The buttons on their own board with their own MC14490 ic too.
As for the boards I used, I will mention at a latter time, since I am expecting confirmation from the manufacturer to get the OK to mention their name.
In the mean time, enjoy some early photo's. These will be published shortly.
July 04, 2008
The first 64-bit, superscalar processors in VIA's x86 platform portfolio, VIA Nano processors have been specifically designed to revitalize traditional desktop and notebook PC markets, delivering truly optimized performance for the most demanding computing, entertainment and connectivity applications.
Building on the market-leading energy efficiency of the VIA C7® processor family, the VIA Nano processor family offers as much as four times the performance within the same power range to extend VIA's performance per watt leadership, while pin compatibility with VIA C7 processors will ensure a smooth transition for OEMs and motherboard vendors, providing them with an easy upgrade path for current system or board designs.
The VIA Nano processor family leverages Fujitsu's advanced 65 nanometer process technology for the ideal blend of powerful performance and energy efficiency. Underscoring VIA's leadership in processor miniaturization, the VIA Nano processor comes with ultra compact dimensions, enabling a new generation of small form factor designs and new, smaller applications for the x86 platform.
- Package size: Compact VIA NanoBGA2 package (21mm x 21mm)
- Die size: 7.650mm x 8.275mm (63.3 square mm)
About the VIA Nano Processor FamilyBelow, you can see an image that shows various consumption info for this new VIA family of processors. You can click on the image, to see it slightly bigger.
At this moment, the CPU's are still not available for the desktop. VIA is looking for a 3rd Quarter availability.
Now there is one catch. Since the departure of Socket 7 cpu's, when all the manufacturers were building for the same socket, it DOES mean that you will have to buy a new motherboard for this CPU, just as you would, if you wanted to go from an Intel to an AMD and vice versa.
I thought to start with this company, since recently, they announced a few good things. Mostly of interest is their new CPU line, the VIA Nano - Isaiah.
Some of you might remember a cpu company called "Centaur". Well, they are part of VIA. Geesh, have I been out of the news updates or what?.
Anyway, the company's that I am aware of, that have rights to the x86 architecture are/were:
AMD, IBM, INTEL, VIA, SiS and a few other companies that have either closed, are not in the PC market anymore or have been bought out by other companies.
This CPU is VIA's 1st 64bit CPU, they are similar I guess to the Intel Celeron - M, since that is also what they compare it with. I say this, according to their site, this is the one that it is being compared with. You can see their own charts and info here. It looks like it will be a great mobile Cpu for people that do NOT need multi-core solutions, and for desktop users looking for a HTPC with a very small energy footprint! It seems to be a very attractive solution for people that will NOT need to play games, or very limited gaming or older single threaded games. That is my assumption at least. It also has a lot of security features not found in the Intel/Amd camp. This would be also an ideal CPU for business's or people looking to have a very small box, no really!
If you go through their site, you will see how small their motherboards are! I would NOT have any issue AT all, to have a system, based on this CPU @ 1.8GHz and their S3 Chroma 440 GTX as my main use computer! I normally browse the web, do emails, have some other things going on like video conversion from time to time. I am NOT the kind of person that would convert a video file, and want it finished in 1 minute! I do have a life, and don't mind if something will take a while to complete, even doing seti@home or folding@home etc, i think it will be ok. Sure, it will not be the fastest and best, but then again, if I want to live away from the grid, be with solar or other alternate power supply, this will fit the bill perfectly. At the moment, I have a power hungry P4 3GHz - 530. Yes, I have my pc since November, 2004 with one of the only available PCIe cards at the time available to me, an nVidea GeForce 5750!!!
The good thing would be, the system would be much more quieter, due to less fan speed needed for a 25W CPU, or maybe a great Heatsink to be totally quiet if that is your goal.
I will post a few pages from their PR. It seems too good to pass up if this is the segment that you fall in to, that being HTPC, Low power usage or a simple no frills pc.
Ok, on now to the PR.