EverCool Variable Voltage Mod

[ledouxmike]

I think I'm gonna go with the smaller box. I really like the looks of the VV Splash and that's the size they are using so I'm gonna go with that one. Now to find some high amp switches that will actually fit, lol

 

[raceengine]

hohoho... just finished and tested my very own everc00L module. still dont know what box to put it in. i got a twin 18650 box with bout 2"x1" space on top of it that might be able to squeeze everything there. cant seem to find tantalum caps here with 10v 100uf so I used electrolytic ones. other than that I followed everything on bigblue30's schematics. A big thanks to bigblue30 and all the others that helped.

now to do another one...

 

[Old_Trekee]

raceengine, If you look at the data sheet on the TI chip, they do not recommend tantalum caps at all on the input and only on the output if you will be operating at temperatures below -20C. I'm using electrolytics on both in and out and a ceramic MLCC on the output(which probably isn't necessary) to smooth out the ripple to make sure I have no problem with the madvapes Voltage Meter.

 

[Old_Trekee]

By the way, where'd you find the double 18650 box? Sounds like just what I need. I was going to have to use 14500 with the boxes I found, but really want to go with 18650's.

 

[retird]

raceengine, If you look at the data sheet on the TI chip, they do not recommend tanatalum caps at all on the input and only on the output if you will be operating at temperatures below -20C. I'm using electrolytics on both in and out and a ceramic MLCC on the output(which probably isn't necessary) to smooth out the ripple to make sure I have no problem with the madvapes Voltage Meter.

Just finished a mod with the TI chip(using tanatalum caps). Added the MadVapes Voltage meter into this one. Working wonderfully. Have made other mods with the TI chip and electrolytic caps and they work wonderfully also.

 

[misterD]

By the way, where'd you find the double 18650 box? Sounds like just what I need. I was going to have to use 14500 with the boxes I found, but really want to go with 18650's.

you can probably fit 2 18650 in here
Project Enclosure (3x2x1") - RadioShack.com

 

[raceengine]

By the way, where'd you find the double 18650 box? Sounds like just what I need. I was going to have to use 14500 with the boxes I found, but really want to go with 18650's.

Here's where I got mine

http://cgi.ebay.com.my/ws/eBayISAPI.dll?ViewItem&item=190531401443&ssPageName=STRK:MEWAX:IT

hope that helps

 

[battousai501]

i dunno if this has been touched upon, but finding the capacitors that have the value of 100V 10uf is a pain, nearly impossible here where I live, and as such, I wanna ask if it is ok to forgo the caps totally?

 

[ledouxmike]

I believe 10v 100uf is the one to use.

 

[rchriste]

i dunno if this has been touched upon, but finding the capacitors that have the value of 100V 10uf is a pain, nearly impossible here where I live, and as such, I wanna ask if it is ok to forgo the caps totally?

If I remember right (you can go back and read the entire thread if you want to find it) BigBlue contacted TI about this question and their people recommended that the caps NOT be omitted for safety reasons. Proceed at your own risk would be the appropriate saying here. I personally wouldn't mess around with stuff like that when using this type of battery. I don't want to do anything to make the battery mad.

I've gotten stuff turned around backwards now and then. Either you're looking for the wrong part or you typed it wrong in your message. You will have better luck looking for 10V 100uf caps locally.

 

[battousai501]

thanks for the prompt response, ledouxmike and rchriste, but I doublechecked the "shopping list" posted by one of the members and I quote:

Parts list:
TI PTR08100W
Mod Box
Battery connector of your choice
Normally Closed (N/C) momentary switch
On/Off switch (SPST) (rated at 2.5 amps or more) if your box is not equipped
2x 100v 10uF capacitors (I used tantalum capacitors)
2x 220 ohm, 1/4 watt resistors
1x 200 ohm, 1/2 watt potentiometer or trimmer resistor
1x 5v LED (color of your choice)

additional parts:
2x 14500 li-ion batteries
battery charger

optional: second "on" LED to let you know your mod is on (as opposed to a single, "fire" LED)

so it's recommended, but not that detrimental to omit those? or what can you guys suggest as a replacement cap?

 

[bstedh]

I think that was a typo on his part as everyone has been discussing 10V 100uF caps. I could be wrong but I don't think I am =] a 100V cap would not be needed in any way. If you have any old computer motherboards ready for the scrap heap you may be able to find them on there. The voltage rating is not that important as long as it is bigger than the voltage you are running through it. The farad ratting is the important factor.

 

[battousai501]

ok, so it would be 10V, 100UF? i'mma visit my local electronics shop yet.. thanks for the response! can't wait to make one of these... by the way, where do you guys get the 18650 boxes?

 

[ledouxmike]

ok, so it would be 10V, 100UF? i'mma visit my local electronics shop yet.. thanks for the response! can't wait to make one of these... by the way, where do you guys get the 18650 boxes?

Check out the spec sheet on the TI chip. Check out the diagram. It shows a 100uf on the input and one on the output. It doesn't state voltage but 10 volts is good for our application. http://focus.ti.com/lit/ds/symlink/ptr08100w.pdf

 

[Java_Az]

the voltage rating just means it can handle up to that voltage and no more. If you slap a 10 volt on there you just have to make sure your supply voltage is not going to be over 10 volts. If you look at some of the approved caps on the data sheet like the Panasonic's they are rated @ 35 volts. So you can use higher rated voltage caps without a problem you just don't want to use ones that are lower then the supply voltage which would be 8.4 volts with two Li-ions in series.

 

[battousai501]

ledouxmike and java_az, thanks for the response, i'm learning something new... will check if I can get any 100uf caps... does it really have to be tantalum? and each cap should be able to handle at least 9 volts? sorry, noob here

 

[Java_Az]

Doesnt have to be tantalum. Really the data sheet says to use electrolytic caps but they are a bit bigger also cheaper. So if you have the room you can use electrolytic, If not go with tantalum and pay a bit more. Personally i would try to go with caps rated @ 16 volts to be on the safe side 9 volts is cutting it pretty close.

Edit: also doesn't have to be 100uf you should be good to use anything from 80uf to 380uf

 

[battousai501]

Doesnt have to be tantalum. Really the data sheet says to use electrolytic caps but they are a bit bigger also cheaper. So if you have the room you can use electrolytic, If not go with tantalum and pay a bit more. Personally i would try to go with caps rated @ 16 volts to be on the safe side 9 volts is cutting it pretty close.

thanks for the tip! will have to look for caps, preferably electrolytic, since i saw the datasheet and I think they recommend ceramic caps the least...

 

[breaktru]

Today I received 6 Free Sample 100uf, 10v Tantalum's from AVX Corp. Took a long time but free is free. I forgot all about the order until it showed up at the door today

 

[battousai501]

Today I received 6 Free Sample 100uf, 10v Tantalum's from AVX Corp. Took a long time but free is free. I forgot all about the order until it showed up at the door today

how'd you get the the sample? maybe I can go down that route... hope they ship free to the philippines