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.