My Latest Boxmod, 5V I built for my wife

Built my wife a new mod tonite, it has a 5volt controlled 4-pin 3A regulator (from Madvapes) and three LED's (a green power light and 2 pink vaping lights), all stuffed into a white translucent 2-AA box (also from MV). I have been working on this all evening, in the process I burned up one regulator, went thru 2 mini PC Boards, finally said "heck with it" and just direct-wired the stupid thing. It's ugly on the inside but cool on the outside. It's hard to stuff all that junk into a tiny box, after all...

It's a "girly" mod with the pink lights, it glows pink in the dark ..

It will run at 3.7V with a 14500 battery or at 5V by stacking two 14250's (which I will have to order). As far as I know, this is the smallest 5V boxmod you can make.

Everything fits in there quite snugly, considering not using any epoxy or hot glue at all.

Yes, I fail sometimes, but lifer is one big learning experience, isn't it?

Here are some pics.





By asnider123 at 2011-03-18

 

That's a nice little box, but it ain't the smallest. I saw a thread where a guy made a 5v box in a 1AA box. Of course, he used unprotected CR2s like a suicidal moron (not really THAT dangerous, but not safe either). The small size is nice if necessary, but the problem with those 14250s is the crap bat life. What are they, 300mAh?

You turn out some trick stuff, though. Wish I had your ability. High Five!

 

yup, 300mAh! May stick to 14500. The neat thing about this one is the chip itself. It has a control pin so you can use small low-amp switch without burning the switch out. At 3,7v it works like a mosfet, with higher voltage, it restricts output to 5V @3 amps.

I am wondering if you can use a standard 3-pin regulator for the same purpose ??? Putting the switch on the ground pin should control the output I think

 

Not sure on that. You may get the full 3A on that one. Have to look at the Datasheet.

So, VV is next, huh? I'd recommend you head on over to TI.com and order some samples of the Evercool and that other V-reg so they'll be there by the time you're ready to build it.

 

3A on the ground pin? I think the ground pin is just for line regulation current (10ma) .. I have my first 4-pin reg (that I snapped off the pin4 (control pin) .. others seem to work .. I will experiment, they say pin 4 if left floating, is ignored.

Vreg .. yah!!! Sounds like a good future project. Or possibly a solid-state capacitive touch-switch (anyone have info on how to do this?)

 

My understanding (quite probably wrong) of it is that the ground pin carries the same current as the hot. If there's a control pin, or MOSFET, then you can resist a side wire down to the mA range to allow for a lighter switch, but you can't resist the Ground or the whole circuit's current will drop. Correct? Or am I totally lost?

 

Chaos is correct.

The current travel from the anode to the cathode (or "+" & "-") would be the same amperage.

you would need a switch intended to handle the load.

3A is recommended for anything we make even though 3.7V devices could get away with a 2A in most applications.

on a four pin regulator the control pin for all intens and purposes acts like a relay on a car. it allows a minute amount of current to activate a larger "switch" that is capable of handling larger current to power hungry accessories.

When the control pin sees current (from the control pin through the internal switch in the regulator to the ground) it triggers a connection to the VOUT pin allowing the regulator it self to be the switch.

I am unsure of the functionality of it now that you have removed the control pin. It is to my understanding that this is needed to switch on or "close the circuit" of the regulator.

 

I think on some of the 5v Vregs that the control pin is only necessary to Interrupt the path to ground. If the path to ground from the control pin is interrupted then the Vreg closes, if it's grounded the the Vreg opens. If it's absent I'm guessing the Vreg will either always remain open, or not function at all.

 

I don't know ??? I am shooting in the dark here, but I thought the load to ground would be full current, but not the input to ground pin current, it is only to provide power for the components within the device .. I could be all wet though .. logically, if full current is drawn on the negative pin, the a 3 amp circuit would actually draw 6 amps (3 internally, another 3 for the load) ?????

Someone jump in here if they have more info please

 

Seriously. I just went and looked at the circuit diagram I've got for the EverHot and saw that there's no resistor on the .5A switch for the control. Now I'm wondering if I'm completely wrong about the ground.

 

Update #1 .. I dug that broken regulator out of the trash and hooked it up to a 13.8V power supply (Vin or VCC). Note that pin #4 (the control pin) is busted clean off Results: solid 5.01V output (Vout or VLoad) .. good deal, I haven't wasted my $2.39

Next experiment: current drain on ground pin of chip..

 

Experiment #2: put switch on ground pin. When closed: 5V, switch opened: 15V

Darn, I wasn't expecting that ... next experiment: 2 resistors to put ground pin above 0

 

OK sorry I am confused then?? if there is not a completed circuit between the control pinn and the VIN or grnd then how does this act as a switch??

If it is putting out power (VOUT) while nothing is connected to the control pin then what is the point of having it??

Installing a switch between the VIN and VDIS would accomplish what? Turning it off?

Anyway to answer your question about the amperage here is a quick and rough picture example to show you what I mean by the 3A circuit. It does not push 3A through all channels just the ones that demand it.

Also I could be wrong investigate all this for yourself and make sure the info is valid, if not come back and straighten me out. View attachment 1037

 

You are correct, only this is a positive regulator, so the battery should be reversed.

Experiment #3: dismal failure still can't get it to switch off without a control pin.. Well, at least I have parts necessary for a really cool 3amp automotive passthru with no need for an inline battery The chip is giving me a solid 5Vout with 13.8Vin and no connection to the control pin. I think I will build it and see how it works.

 

Oooops

I never can remember to get the battery right side up.

For some reason I always put the narrow line up like the button top on a battery.

I guess i will never get it right....LOL

 

DC-DC Step-Down Converter Module [POW-SD3018] - $6.95 : MDFLY electronics, Your electronics supplier!

3A Adjustable step down switching voltage regulator

Also to help you out on your VV mods unles you want to build you own VV board.

I have used the first one in a home made mod that used an old laptop power supply and work very well. Have measured the A up to 3.5 so far but you can hear a small whine from it. Has handled great.

The latter is a regulator that I plan on using if I break down and decide to modify my Phidias into a VV device with 2X18350s

 

Ah the mod a day .

 

i have two questions.. maybe u can help.
1) how to i connect (pos) (neg) to the 510 connector that the addy screws into?
2) any luck hacking apart 510 batts for connectors?

 

1) solder
2) Yes most of them are press fit into the battery tube.