Adjustable voltage box mod

[SurvivorMcGyver]

LOL, hey you must have posted before I updated the LED readout I was also thinkin of SMD Caps rather than through hole ones, I like the 25v ones you picked out, seen any surface mount ones that would fit the bill?
Next step would be a USB charge circuit.
Dan

Just a slight recomendation to mod the mod: Per your schematic you are sampling battery voltage for the LED display and not Vo to the atty (which might be helpful for your adjustments) Perhaps you could put a silde switch in there to test both (from the batts then to the atty)..

GL on the USB charger. Something that will help there is to have a dynamic power path circuit so that you can vape and charge at the same time
Toodles and happy modding all

 

[Scubabatdan]

Just a slight recomendation to mod the mod: Per your schematic you are sampling battery voltage for the LED display and not Vo to the atty (which might be helpful for your adjustments) Perhaps you could put a silde switch in there to test both (from the batts then to the atty)..

GL on the USB charger. Something that will help there is to have a dynamic power path circuit so that you can vape and charge at the same time
Toodles and happy modding all

Good catch, the LED display I have ordered measures up to 6 power sources, so I could make a path from the atty to the LED so I could see the battery level and the output power to the atty. Good catch, I would love to have a dynamic power path, but I also want the li-on series charging that works.
Thanks for the suggestion.
Dan

 

[SurvivorMcGyver]

Good catch, the LED display I have ordered measures up to 6 power sources, so I could make a path from the atty to the LED so I could see the battery level and the output power to the atty. Good catch, I would love to have a dynamic power path, but I also want the li-on series charging that works.
Thanks for the suggestion.
Dan

{Chuckle} I too have the same ones ordered. Thinking I can rig it to rotate/test the condition of each battery and then vape voltage when present. If one could only contol the cycling and "lock in" on the specific reading desired that would be nice (thus my switch recomendation).

You can't beat the price though!! -- I've been eyeing these (errr... similar ones) for MONTHS as a posible addition. Hoping it will NOT cycle through the "empty" pin readings -- that would be a bummer.

I've also been toying for months trying to design a BQtiny (from Ti) circuit for TWO batteries. Diodes and two chips are my only solution. But this may be promising -- Just came across it tonight. My search parameters indicated it had a dynamic power path but, after a quick review, I couldn't find the FET output nor diagram for it in the specs.... maybe I need to spend some time with it. For ME the fet out must be 3A and preferably Vin minimum - if that's even possible with the charging circuit and other overhead involved. The 383 already drops about .45-.6 volts.

Well anyway, thats my two cents for the night -- Keep us posted and keep with it my friend!!

 

[hova]

and i thouht i was hot .... having soldered a couple times , and knowing a little more than the average auto tech , as far as electronics on cars goes , but you guys blow me away with your knowledge..


keep at it , for those of us who just dont get it...

-hov

 

[Bubo]

Okay - I'm gonna cross post, because people aren't watching the NicoDrip v1 thread as much as this one....

Okay - stupid question (Just to confirm....)
I went to RS and got all of the little bits.. But while looking at the resistors - I had the option of getting 1/8 Watt, 1/4 Watt and other wattages... Panic set in.....

So far I have been doing well by putting parts in EXACTLY as shown.... (Nothing has blown up yet!) Can someone allay my fears and tell me which wattage would be best (Or do all work?)

 

[bigblue30]

So far I have been doing well by putting parts in EXACTLY as shown.... (Nothing has blown up yet!) Can someone allay my fears and tell me which wattage would be best (Or do all work?)

Let me try to answer this…

I have no idea what resistor you are talking about so I will just use the example below.

Wattage ratings on resistors are there to tell you how much power (watts) the resistor can take before it goes up in smoke.

“Smoke is the magic stuff that makes electronics work…If you let the smoke out electronics stop working”

You pick the rating by the circuit you are going to put it in: example.

If you had a 5 volt battery, a switch, and a 5 ohm resistor. You would need a resistor with a wattage rating of 5 watts.

If you take a look at my circuit on the first page (I know that this post has come a long way from there, but it all started with this first post) you will see a 200k from pin 5 to pin 3. Now if you adjust this regulator to 5 volts….you would have 5 volts across a 200k resistor.

That says that you need a wattage rating greater then 0.00013 watts for this resistor. The resistor has a .25 watt rating so it will work. You can always go up in wattage ratting but never down.

Here is a nice ohm’s law calculator that will let you figure out the rating for any resistor
http://www.the12volt.com/ohm/page2.asp Use the [/B]“calculate for power (P) one”

 

[Bubo]

Perfect - thanks BB!
(and BTW - I use a slightly modigied version - “Smoke is the magic stuff that makes computers work…If you let the smoke out computers stop working”)

 

[hova]

ive heard people try to generalize it (......) by saying anything undrer 9v is a 1/8 watt , and anything over 9 volts is 1/4 watt...


i remember them blowing up circuits constantly...

 

[Scubabatdan]

{Chuckle} I too have the same ones ordered. Thinking I can rig it to rotate/test the condition of each battery and then vape voltage when present. If one could only contol the cycling and "lock in" on the specific reading desired that would be nice (thus my switch recomendation).

You can't beat the price though!! -- I've been eyeing these (errr... similar ones) for MONTHS as a posible addition. Hoping it will NOT cycle through the "empty" pin readings -- that would be a bummer.

I've also been toying for months trying to design a BQtiny (from Ti) circuit for TWO batteries. Diodes and two chips are my only solution. But this may be promising -- Just came across it tonight. My search parameters indicated it had a dynamic power path but, after a quick review, I couldn't find the FET output nor diagram for it in the specs.... maybe I need to spend some time with it. For ME the fet out must be 3A and preferably Vin minimum - if that's even possible with the charging circuit and other overhead involved. The 383 already drops about .45-.6 volts.

Well anyway, thats my two cents for the night -- Keep us posted and keep with it my friend!!

Nice chip, only problem is when using protected batteries in series the first battery to fully charge will cut the circuit. According to the data sheet, you have two wires connecting to the two batteries, one on battery 1 pos and one on battery 2 neg. The charger in the previous post has a third wire that connects between the first battery neg and second battery pos. That should charge two protected batteries (LOL I think) we shall see...
Dan

 

[bigblue30]

Nice chip, only problem is when using protected batteries in series the first battery to fully charge will cut the circuit. According to the data sheet, you have two wires connecting to the two batteries, one on battery 1 pos and one on battery 2 neg. The charger in the previous post has a third wire that connects between the first battery neg and second battery pos. That should charge two protected batteries (LOL I think) we shall see...
Dan

Dan,
I have been going around and around on the same thought..... I can not see how a 2 wire charger can be safe. If you use protected batteries then what you said above goes….If you use unprotected then to me it looks like one could over charge.

I have a RC battery that is 7.4 v and 800 ma. It must be 2 batteries in series, but the charger is only a 2 wire charger, plus and minus. There must be a chip in there that balances the 2 cells some how.

I might have to rip one apart just to see how they do it.

 

[kwcharlie]

Dan,
I have been going around and around on the same thought..... I can not see how a 2 wire charger can be safe. If you use protected batteries then what you said above goes….If you use unprotected then to me it looks like one could over charge.

I have a RC battery that is 7.4 v and 800 ma. It must be 2 batteries in series, but the charger is only a 2 wire charger, plus and minus. There must be a chip in there that balances the 2 cells some how.

I might have to rip one apart just to see how they do it.

Only one protection ckt in the battery pack, or the charging ckt goes around the discharge protection. Dan's right, can't charge 2 protected batteries in series. Tell the kids it's OK to now Dan then put them back to that SM work

 

[Scubabatdan]

Only one protection ckt in the battery pack, or the charging ckt goes around the discharge protection. Dan's right, can't charge 2 protected batteries in series. Tell the kids it's OK to now Dan then put them back to that SM work

If you don't eat yer meat, you can't have any pudding. How can you have any pudding if you don't eat yer meat?
You! Yes, you behind the bikesheds, stand still laddy!
Now everyone Back to Work!

We don't need no education
We dont need no thought control
No dark sarcasm in the classroom
Teachers leave them kids alone....

HEHEHEHE
Dan

 

[SurvivorMcGyver]

Nice chip, only problem is when using protected batteries in series the first battery to fully charge will cut the circuit. According to the data sheet, you have two wires connecting to the two batteries, one on battery 1 pos and one on battery 2 neg. The charger in the previous post has a third wire that connects between the first battery neg and second battery pos. That should charge two protected batteries (LOL I think) we shall see...
Dan

Right on target with your analogy. Ok then, I'll just throw this in the mix as a posible solution.

 

[5cardstud]

If you don't eat yer meat, you can't have any pudding. How can you have any pudding if you don't eat yer meat?
You! Yes, you behind the bikesheds, stand still laddy!
Now everyone Back to Work!

We don't need no education
We dont need no thought control
No dark sarcasm in the classroom
Teachers leave them kids alone....

HEHEHEHE
Dan

and schools out for ever.

 

[Scubabatdan]

Right on target with your analogy. Ok then, I'll just throw this in the mix as a posible solution.

Hey... Now I like this This one looks like it allows for a dynamic load (I could be wrong), supply voltage is 8.4v @ 1A but the max VOC is also 4.35, just like the other, but seems to have more of a logic chip to it. Would also have to get the SI9936DY chip.
Have been looking online and have not found a state side supplier yet.

Oh hey I got a digikey box in today!! Yay me, I got my SMD 100M and 47k surface mount resistors, had to rework my original 3.7v touch circuit as the pads were to small LOL, here is a screen shot of the final circuit about .7" in diameter. I will attach the ExpressPCB file to if anyone wants it.
And here is the link to download the free ExpressPCB program:
ExpressPCB - Free PCB layout and schematic software

Here is the link to the touch circuit PCB file, as I could not upload a zip file with out it getting corrupted:
Touch Circuit 3.7v Simple

Added: I am also including a printable reverse image of the circuit that can be printed with a laser printer for transfer onto a PCB copper board for etching. Download here:
Reverse Image of Circuit

Dan

 

[st0nedpenguin]

I could be missing something really obvious here, but is there any reason why every time I order the UCC383-ADJ from TI they send me the UCC283-5?

 

[st0nedpenguin]

So using this:

Would everything still work if the locations of the pot and caps were switched, or would I end up dividing by zero and destroying the universe as we know it?

Oh, and where would I stick an LED should I decide to use one?

 

[bigblue30]

So using this:

Would everything still work if the locations of the pot and caps were switched, or would I end up dividing by zero and destroying the universe as we know it?

It would work the same. as long as the POT is connected to pins 3,4,and 5 and the caps are connected to pins 1,3, and 5.

Oh, and where would I stick an LED should I decide to use one?

If you are looking for the LED to light when you hit the fire button then the LED and resistor (you should be using a resistor) would go from pin 3 to 5 just like the atty.

 

[st0nedpenguin]

Great stuff, I assume if I'm skipping the master on/off switch I just connect the battery + directly to pin 1 as it is on the diagram?

Thanks for all the help again, just need my battery connectors to come in then this thing is ready to roll.

 

[mamu]

Great stuff, I assume if I'm skipping the master on/off switch I just connect the battery + directly to pin 1 as it is on the diagram?

Thanks for all the help again, just need my battery connectors to come in then this thing is ready to roll.

Stoned... the wiring is different for the fire switch if you're not using a master on/off switch.

The way I wired my mod without a master on/off switch was one leg of the switch you're using goes to pin 1 (Vin) of the LDO and the other leg of the switch goes to the Batt + contact. And make sure you have an NO switch, not an NC switch.