EverCool Variable Voltage Mod

[o4_srt]

don't know if anyone has mentioned this, but the current draw on this mod is slightly under an amp at 5.5 volts, with an input of 12 volts (I further modified this mod to allow me to select 12 Vin, from a wall transformer or car power port, or battery powered using a SPDT switch). Interestingly, current increases as Vin drops, increasing to almost 2 amps as you approach the Vout min.

Confused the hell out of me for quite some time, and ended up doing some research; turns out, ohm's law only applies to linear devices, and since the switching regulator is NOT linear, ohm's law does not apply.

 

[WillyB]

but the current draw on this mod is slightly under an amp at 5.5 volts, with an input of 12 volts

How did you figure out the current draw? What ohm atty are you using?

and since the switching regulator is NOT linear, ohm's law does not apply.

If I use Ohms law, P = E x I, 5V with a 2.1Ω atty gives me 12 watts with 2.4A.

If I use P = I 2 x R, 2.4A with a 2.1Ω atty also gives 12 watts.

If I then use I = P / E with 12 watts and 12V I get 1 amp.

 

[o4_srt]

How did you figure out the current draw? What ohm atty are you using?



If I use Ohms law, P = E x I, 5V with a 2.1Ω atty gives me 12 watts with 2.4A.

If I use P = I 2 x R, 2.4A with a 2.1Ω atty also gives 12 watts.

If I then use I = P / E with 12 watts and 12V I get 1 amp.

current draw displayed on lab grade power supply (lambda 0-30 volt, up to 5 amp), 3.2 ohm atty.

asked an engineer at work, it's because the regulator can achieve the same output by lowering the duty cycle, and in order to achieve the same 5.5 volts with a lower Vin, the regulator increases the duty cycle, or something to that effect...not fluent in engineerese quite yet, still taking electives and gen eds

regardless, this was a great thing to find out, since I just so happened to have a 12 volt, 1 amp transformer from an old linksys router that we don't use anymore. It's now sporting a BNC connector in place of the barrel connector it came with, and is powering my evercool like a champ.

 

[st0nedpenguin]

Here is a better layout:

I'm not sure if blue is still able to post here, but hopefully somebody can answer this supernoob question.

The only thing that has me confused is where exactly the LED is tied into the equation, I'm assuming from the picture that I just need to drop it in between 4D and 3E? And if so, does it matter which leg goes to which socket?

 

[WillyB]

I'm not sure if blue is still able to post here, but hopefully somebody can answer this supernoob question.

The only thing that has me confused is where exactly the LED is tied into the equation, I'm assuming from the picture that I just need to drop it in between 4D and 3E? And if so, does it matter which leg goes to which socket?

Column 4 is Vout (positive), column 3 is GND (negative). I see no reason that you can't use 4D and 3D for your LED. And yes LED's are polarized, the longer leg is usually positive, you can attach your resistor to either leg.

Also note there is no reason to worry about pin 1 and it's column at all. You only need a to bend/solder pins 2 thru 5, on a 4 column strip board.

current draw displayed on lab grade power supply (lambda 0-30 volt, up to 5 amp), 3.2 ohm atty.

asked an engineer at work, it's because the regulator can achieve the same output by lowering the duty cycle, and in order to achieve the same 5.5 volts with a lower Vin, the regulator increases the duty cycle, or something to that effect...not fluent in engineerese quite yet, still taking electives and gen eds

regardless, this was a great thing to find out, since I just so happened to have a 12 volt, 1 amp transformer from an old linksys router that we don't use anymore. It's now sporting a BNC connector in place of the barrel connector it came with, and is powering my evercool like a champ.

Yes, but as I demonstrated Ohm's Law does indeed apply.

 

[st0nedpenguin]

Column 4 is Vout (positive), column 3 is GND (negative). I see no reason that you can't use 4D and 3D for your LED. And yes LED's are polarized, the longer leg is usually positive, you can attach your resistor to either leg.

Also note there is no reason to worry about pin 1 and it's column at all. You only need a to bend/solder pins 2 thru 5, on a 4 column strip board.

Thanks for the reply, just waiting for my last package of parts to arrive then I can finish this thing off, fingers crossed the thing doesn't blow up the first time I hit the button.

 

[Gummy Bear]

Good luck, Hope you took lots of pics. I have all of my parts in too, except for one, it should be in tomorrow. But I'll post it in the other thread because I went with the quick easy one, I didn't feel that I was up to this one yet.

 

[o4_srt]

Column 4 is Vout (positive), column 3 is GND (negative). I see no reason that you can't use 4D and 3D for your LED. And yes LED's are polarized, the longer leg is usually positive, you can attach your resistor to either leg.

Also note there is no reason to worry about pin 1 and it's column at all. You only need a to bend/solder pins 2 thru 5, on a 4 column strip board.



Yes, but as I demonstrated Ohm's Law does indeed apply.

I was regarding modern ohm's law as it is commonly taught (V=IR), not the power law as you described.

 

[st0nedpenguin]

After ogling the diagram a little more, I'm wondering if it'd be easier to just solder the negative side of the LED directly to the atty connector and then the positive side to 4D?

Answer being yes, just waiting on gobs of epoxy (technical term) to dry a bit and I'm good to go!

 

[o4_srt]

After ogling the diagram a little more, I'm wondering if it'd be easier to just solder the negative side of the LED directly to the atty connector and then the positive side to 4D?

Answer being yes, just waiting on gobs of epoxy (technical term) to dry a bit and I'm good to go!

as long as the you still use the resistor, it will work fine.

 

[st0nedpenguin]

Yeah, I still used the resistor, it was a nightmare getting the whole thing packed into the tiny space I left for it all behind the atty connector though.

The connector itself was so much easier to work with since it was sealed though, this is my first non juicebox mod so I'm used to the nightmare of taking those little center terminals out and fiddling about for 2 hours soldering to them and getting them back in.

 

[Para]

Location
Amboy, WA

Small world....I used to live in Battle Ground. LOVE that area; I miss it a lot.

 

[grantemsley]

Just a tip to anyone trying to make one of these...if you accidentally get the pins wrong (had the board upside down, counted backwards) and hook the batteries to the output of the regulator...you will let the magic smoke out. At least I think that's why it doesn't work anymore. With it hooked up properly now, my ultrafire batteries look like they auto shutdown. Oh well, I had it in a socket not soldered directly, so I can replace it easily enough.

 

[bigblue30]

Just a tip to anyone trying to make one of these...if you accidentally get the pins wrong (had the board upside down, counted backwards) and hook the batteries to the output of the regulator...you will let the magic smoke out. At least I think that's why it doesn't work anymore. With it hooked up properly now, my ultrafire batteries look like they auto shutdown. Oh well, I had it in a socket not soldered directly, so I can replace it easily enough.

I hate it when the "smoke" comes out.....

 

[kwcharlie]

Small world....I used to live in Battle Ground. LOVE that area; I miss it a lot.

And i got a Blue Dog print, from NO, here in Houston, where in TX are you?

 

[netspyman]

well i made this mod after i got all the parts. the first time i hit the fire button the led turned on then off and wouldn't come on again. I was like what the f. I started checking everything and it all looked right. I thought i had gotten a bad chip from ti. I then took it apart and started checking things one more time and found out i had fried a cap.(placed it in backwords) installed new caps and put it back together and it is vaping great. Thanks Blue this is my go to vape now.

NETSPYMAN

 

[bigblue30]

well i made this mod after i got all the parts. the first time i hit the fire button the led turned on then off and wouldn't come on again. I was like what the f. I started checking everything and it all looked right. I thought i had gotten a bad chip from ti. I then took it apart and started checking things one more time and found out i had fried a cap.(placed it in backwords) installed new caps and put it back together and it is vaping great. Thanks Blue this is my go to vape now.

NETSPYMAN

I am glad you got it working. I send you the pic of the voltmeter also.

 

[squeeze]

Very cool!

 

[Jetmec]

Big blue I used your guide to build the evercool VV and it is my go to now, thanks for posting. I have the parts to build another one for a backup in case something happens to it. You also had a post on a volt meter that you built but the schematic is no longer in the post, can you re-post that so I can build one of those. Thanks.

 

[Budjiman1]

Does anyone know where I can buy a thumbwheel pot???? ALSO... Does anybody want to sell some extra caps???? The 100uf caps we need for this...