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hi there, got most of the parts to make this mod just wondered what voltages are the caps you have used cheers....love this mod...
Are there any other PChan mosfets you guys would recommend? I'm reading spec sheets, and it's making my head hurt trying to balance the one depicted vs the ones at http://www.onlinecomponents.com/
I think I'm reading this right, but please run a sanity check for me: http://www.onlinecomponents.com/datasheet/si9434dy.aspx?p=12421764&Resource=1 . It looks like the values are right based on all the info above.
So that should equate to a lesser pull up resistor, right? I'm starting to feel like im too old to be learning this fast.
Well, have read everthing on his thread andI feel like I have a good grasp of what to do. I have just one question that I need hel[ with. I would like to use one of those metal switches that have a led circle in them. someone called it a tron switch. I don't know where but I did see one somewhere but it was rates at 2 amps. If I canfind i again will it work and if not does anyone know where to find one.Thanks Mick 8844
Thanks breakthru followed u guide works a treat.....my vv emergency booster box range 3.5v to 5.5 v
I stock pile stuff and forget where things are
I used the same emergency power supply (only in white), but I am "old school" so I used 2 batteries and an LM350 linear regulator. The adjustment screw is behind that little hole. The USB is still functional, did away with the light. Shown here with an EVOD tank. Oldie but goodie, still works great. Like yours a lot better!!! Clean build. Is the toggle spring-loaded?Forgive the crummy picture, never been any good with photos, but you get the idea.Uploaded with ImageShack.us
I used the same emergency power supply (only in white), but I am "old school" so I used 2 batteries and an LM350 linear regulator. The adjustment screw is behind that little hole. The USB is still functional, did away with the light.
Like this?It's too large for a AA battery box. Comes in different colors. See --> HERE
Looks like you have a well thought out mod going there Bob. I'm not the best person to comment on the schematic but it looks correct to me. That pot is a unknown to me. As for the DS1809 I found then at Digi Key. http://www.digikey.com/product-detail/en/DS1809-100%2B/DS1809-100%2B-ND/1197191Hope that helps
Great job Breaktru!! this is an awesome mod. I want to thank you for all the hard work you put into designing your mods AND THEN taking the time to run this forum and share your inventions and your knowledge. (that goes to all the contributors of the forum as well) It takes a lot to make the mods but you go even further and help everyone else too. WAY TO GO!!!This mod has all the features i wanted to incorporate when i found this forum. At that time i was just going to put a vamo board into a box but this seems like it will be much more satisfying. Ive read through this and a few of your other topics related to variable volt mods and I think I'm ready to order parts but before I do I wanted to double check a couple things. (normally I would just buy parts but I'm unemployed at the moment and trying not to spend too much on unneeded or wrong parts)Unfortunately I wasn't able to get the ptn04050c sample from TI. That's OK, Arrow has em for $12-$13 ea. I also wasn't able to find the digital pot you referenced and was hoping i could get your guys expertise on this one and double check to make sure my wiring of it is correct. I really don't like that its connected straight to the battery before the mosfet but according to the data sheet (pg 17) it needs to be or wont retain wiper setting Also, do you think that 1 to 10uF loesr cap is absolutely necessary? Hate to have to cram another one of those in there.
I have ordered 0450c's from them and was charged 14 bucks for shipping.
I believe you can fore-go the 1 to 10uF caps. They are needed for filtering ripple of a power supply. We are using straight battery voltage so it should not be a concern.
I would like to suggest not using a 14500 battery. Much better results are had with a high drain 18500, 18490, 18650 or Li-Po 20C battery.
The mosfet source to gate resistor. 15k will most likely not work. It depends on your skin moisture and humidity.
how do i find out the actual C rating of a certain battery without having the data sheet for it? Is there a simple bench test without pushing it to its limit and blowing up a spare one? they are protected so i guess i wouldn't have to blow one up.i think VV mod with 3400mah in a 3xAA box w/recessed cartomizer would be awesomeI'm not planning on using a touch sensor, just a tactile switch to save room.why wouldn't you recommend those tactile switches?
A cell phone battery has a low C rating and will not handle the demand of an atty coil. I think it's like 2C.To calculate the C rating you would need to know the battery internal resistance
You need something that protrudes through the box like a standard tact.
2C is actually higher than i guessed. If they are 2C then .... paralleled 1700mah = 3400mah 3.4Ah x 2C = 6.8Amps Thats gotta be more than what a 14500 trustfire is putting out, no?thanks again for the advice, helps a lot!
Ok I have my 4050 mocked up on the bench. I'm using the DS1809-100 with 2 tach switches. When I test fire it its at 3.8 volts on the meter. I tried to adjust the pot and nothing I followed the org post but used a tach switch to fire (that seems to be working) all is good except the DP here is the set up I usedAny help would be awesome. After 2 hours I'm Outta ideas
DC-DC converters create a lot of ripple and noise. The capacitor is needed to keep the supply voltage stable for the pot. Took me a while to figure out what you meant by "loesr", but now I see that's "low ESR". The best capacitor to use for that purpose is an MLCC cap. Use a 1uF. They are small, inexpensive, and have the lowest ESR of any general purpose capacitor.The capacitor needs to be connected as close as possible to the pot leads, both power and ground which are pins 8 and 4 on the pot in your drawing. You may or may not have a problem without one, but it's standard practice to add a .1 to 1uF cap at the power and ground pins for any chip that uses digital logic. Cell phone batteries are typically 1C. They are probably the most hazardous batteries you could use to power an atomizer except maybe those 3.2V CR2 Li-Ions, those are horrible too. They're not designed for the drain currents you would see with an atomizer. I've seen lots of people talk about using cell phone batteries and even actually attempt it. If you use a flat LiPo cell, it should be at least 10C and must at least have short circuit protection. Just use an IMR cell. Those are the safest ones for our purposes.Digital inputs from tactile switches typically need to be "debounced". I don't know about that chip, it may have debouncing already built into the switch inputs, but that's normally something that needs to be considered. Switch contacts make a lot of noise when opening and closing that digital inputs mistake for multiple switch activations. You usually have the option of debouncing in software or hardware with MCUs, but with that one, you can only hardware debounce.You can try it as wired in the diagram, but if the pot jumps around on you, that's what's causing it. Hardware debouncing is usually not a big deal, just a matter of two resistors and a capacitor, but since you are trying to minimize part count and it's already known to work without it, should be okay. Just bringing up the issue of switch debouncing as a matter of practice.
Ok. I think I found a work around for this ID10T move I made. LoL. I was looking for a small step up to get 5v from my 3.7 and I came across this http://www.pololu.com/catalog/product/211It looks like it will fit the bill and be small enough. Any feedback would be appreciated
i think you link got cut off, got a page not found errori think instead of adding more circuitry ( keep it as simple as possible) your best bet would be to get a different digital pot that has 3v operating voltage.
Your probably right there. I jumped the gun and ordered the 1809's . I might have to order the one you are looking at.
DC-DC converters create a lot of ripple and noise. The capacitor is needed to keep the supply voltage stable for the pot. Took me a while to figure out what you meant by "loesr", but now I see that's "low ESR". The best capacitor to use for that purpose is an MLCC cap. Use a 1uF. They are small, inexpensive, and have the lowest ESR of any general purpose capacitor.
I've been tring to solider up the AD5228 and this chip is just way to small!!!! Is there any other chips still in production that will work for a DP for us? Sorry to be a PITA but I'm hell bent that this mod will have a DP...lol
Yes the the AD5228 is tiny. It's a TSOIC foot print. It is also a 32 step.I searched long and hard for a replacement for the DS1869 and finally found an OnSemi PDIP-8 that looks like it will work.Part number is CAT5113LI-00-G. Has 100 steps, supply current 100uA, 2.5v to 6v supply, PDIP-8 foot print and retains wiper memory.Also a DS1804-100 is about the same except the supply current is 400uA
i looked at both of those and several like those. my concern with those was simple operation. appeared to me that you need a signal input via microprocessor instead of just simple tact switches. how do you get around that?you don't think 100 steps to get from 3.5 - 6 volts is too many?
