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Hi, and welcome to part 1 of making a CMOY Headphone Amp for the Eclipse Mints tin.
The tin is this one here, and it comes in different colours.
It is much smaller than your average Altoids tin.
This here is your average Altoids tin, that many of you overseas will be familiar with,
and this is the common Eclipse tin which is readily available here in Australia.
So, as you could see, it is much smaller, compared to the Altoids.
- This project has taken me a very long time
due to various setbacks. Here is a voltage multiplier that I had done last year. I will
be using only these parts here of which back then where used for something else plus the
CMoy, having done it on a breadboard recently I discovered a little error.
- Comment: Not really, the circuit is working correctly, just that I forgot that I will
have the multiplied power, minus the voltage drop from the diodes ;-)
So here is the updated version, basically the TC962 multiplier x2, so you have got one
multiplier and the inverter, and then you have the positive and negative regulators
to keep the voltage at a steady... to keep it steady. Now this here is the original version,
of which is the multiplier, the voltage regulator and the inverter.
Now as far as batteries go, this is your average your normal 9v battery, as you can see it
can fit nicely in to an Eclipse tin. But for my liking, I like rechargeables, and there
are 9v rechargeables. But, to make my life easier I wanted more space in the Altoid,
in the Eclipse tin. Now there is someone on the internet in Australia that makes a circuit
for that, but because, I don't know how to do nice and very neat boards, this is a common
Vero board or strip board as you can see it is called a strip board, because the copper
tracks are in strips, and they are also at 0.1" apart.
Now what I will be doing is, I have two options for the Eclipse tin, option number 1, is use
AAA batteries two of them, being Li-Ion, these are Ni-MH, so Li-Ion, are 3.6 /3.7v on average,
and their range is from approx. 3v to 4.2v when they are fully charged, and you can also
use LiFePo4 of which are 3.2v on average and get charged to 3.6v and can go down to 2v.
Now these are the CR123 or LR123 these are as you can see rechargeable batteries, these
do not have the protection circuit in them, but what I do like about them is, that they
are supposedly, as you can see here, 1800mAh at 3.6v.* So two of these can fit end to end
without the holder of course inside, just need some heat-shrink tubing, and the same
goes for these AAA batteries of which you can see, fit in pretty nicely, and if you
put them in a shrink wrap you can put them more easier, pull them in and pull them out,
put them in and pull them out. And will fit in nicely with this here of which is a standard
pcb strip board that you can buy off the internet. So as you can see, battery number 1, and battery
number 2, and you still have space in there and it does not impact on the switches. Now,
as you can see, these two batteries in series, provide 1 point, 8 point one two volts.
Now, here comes the test for the voltages, as you can see it is just 7.27* for arguments
sake, you can say 2 point 3, um 7 point 3 (7.3v) sorry and for the other one, it is
at 8 volts or just above 8 volts, 8.03 8 point 04. So that is from the voltage regulator,
and the other is from the inverter part. That is why I needed to update that design, so
it can be the same from both sides.
* 3.6v @ 1800mAh = 6.48W or x2 batteries = 7.2v @ 1800mAh = 12.96W for the LR123A batteries.
if AAA, of which are 600mAH, then 2.16W and 4.32W respectevily.
*7.27v = 8v - 2 diode drops. I am using 1n4148 diodes for the breadboard. I can use 1n5818
etc for a slight improvement.