While Waiting for my EQ- VV Bottom Feeder alternatives

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Friend of Atlas

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I have a technical question about my RSM and regulating voltage down...

After using the RSM for a few weeks consistently with the setting at 6.1v (unloaded) with a 3.1ohm resistance atty and 2 AW IMR 18350 batteries and this is what I experience:
-When the batteries are fully charged (8.4v) I get 6v loaded voltage consistently. This lasts until the batteries reach 7.6v.
-When the batteries hit 7.5v my loaded voltage drops to 5.9v
-When the batteries hit 7.2v my loaded voltage drops to 5.8 to 5.7v, which to me is a very noticeable drop in warmth and flavor.
-At 7.0v my loaded voltage drops to 5.5v!

I'm not sure why this happens. I suspect it's a function of the battery capacity (700mAh) in conjunction with the regulator being used, but technically speaking I'm not the one to explain it. The regulator is regulating the voltage down to the set voltage and I'm confused why it needs greater than 7.5v battery voltage to go down to a 6v loaded voltage.... Anyone here have an educated guess/answer?
 

jimho

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I have a technical question about my RSM and regulating voltage down...

After using the RSM for a few weeks consistently with the setting at 6.1v (unloaded) with a 3.1ohm resistance atty and 2 AW IMR 18350 batteries and this is what I experience:
-When the batteries are fully charged (8.4v) I get 6v loaded voltage consistently. This lasts until the batteries reach 7.6v.
-When the batteries hit 7.5v my loaded voltage drops to 5.9v
-When the batteries hit 7.2v my loaded voltage drops to 5.8 to 5.7v, which to me is a very noticeable drop in warmth and flavor.
-At 7.0v my loaded voltage drops to 5.5v!

I'm not sure why this happens. I suspect it's a function of the battery capacity (700mAh) in conjunction with the regulator being used, but technically speaking I'm not the one to explain it. The regulator is regulating the voltage down to the set voltage and I'm confused why it needs greater than 7.5v battery voltage to go down to a 6v loaded voltage.... Anyone here have an educated guess/answer?

yeah - couple of things - educated guess- you're loosing alot of efficiency in that circuit - I don't know the details, but I suspect it's not set up to boost.

Also...
- when you stack batteries you do not increase the mAh rating- so you're effictively running a 7.4V (nominal) battery with 700mAh..
- when you put a heavy load on those batterys they might drop to 3.2V each .... if it's not set up to boost, you can't get higher voltage out than you are putting in.....

I expect you see that drop fairly quickly.
 

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OK BUT - when I switch to straight battery mode running 7.3v unloaded (w/all other variables the same) I get 6.9v loaded out of the batteries so you're saying that the regulator requires ~1.1v to run or is it a resistance issue?

Why would it need to boost when it's dropping the voltage down?
 
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jimho

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OK BUT - when I switch to straight battery mode running 7.3v unloaded (w/all other variables the same) I get 6.9v loaded out of the batteries so you're saying that the regulator requires ~1.1v to run or is it a resistance issue?

Why would it need to boost when it's dropping the voltage down?
It doesn't need to boost, but it needs headroom - 1.1 or 1.2V at least- to run.

Either that, or there is something wrong with it.

What does it do with an 18650 when you set it at 4V?
 

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It doesn't need to boost, but it needs headroom - 1.1 or 1.2V at least- to run.

Ok - well that's what I'm getting and why I'm experiencing the drop in voltage while regulated... I didn't realize it required so much 'headroom':(

What does it do with an 18650 when you set it at 4V?

I don't know since I don't really use it with an 18650, but if I did I'd turn the regulator off and then it would just be a 'direct battery' device and I think it would become a non-issue...

But I'll try it out when I change batteries...

EDIT: DUH - I forgot that the regulator requires min of 5V batteries to operate so when using a single 18650 you can't use the regulator...
 
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Shad0w

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It doesn't need to boost, but it needs headroom - 1.1 or 1.2V at least- to run.

Either that, or there is something wrong with it.

What does it do with an 18650 when you set it at 4V?

Ok - well that's what I'm getting and why I'm experiencing the drop in voltage while regulated... I didn't realize it required so much 'headroom':(



I don't know since I don't really use it with an 18650, but if I did I'd turn the regulator off and then it would just be a 'direct battery' device and I think it would become a non-issue...

But I'll try it out when I change batteries...

EDIT: DUH - I forgot that the regulator requires min of 5V batteries to operate so when using a single 18650 you can't use the regulator...

That is a parameter that is dictated by the regulator used. LDO = Low Dropout Regulator so the higher efficiency the lower the "headroom" it needs.
In and of themselves, series circuits with any type of (not micro-controlled) regulator setup are typically wasteful. Thus the need for lowest dropout possible to assure a semi-livable service time. Less energy wasted to heat is more energy used for the devices intended purpose.
In order to use a single cell (18650etc..) you will need to run the device in bypass mode as it will not function otherwise since it never sees the minimum turn on power needed for the buck circuit to run.
As Jim mentions, in a series configuration, you will only ever see the mAh of any SINGLE CELL in the series. You will get roughly 2x the Voltage output though.
In other words, don't expect great cell runtime as you are only ever using the effective capacity of a single cell.
Remember also that since it is not a power regulated device, you WILL see a drop in output that coincides with the drop of the cell charge state coupled with the reg dropout.

Anyhow, hey everyone :)
 

jimho

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Thanks that answers my question completely. So in order to improve the run time on the RSM I would need an LDO type regulator (better) or micro-controlled regulator (best)... Conceivably, I could micro-control the LDO regulator correct? (If I was a different person perhaps:))

no- no- no -no

Now you did it Shadow :) You broght the kids to a candy store and snuck out the back door....


I wrote a nice response - took me an hr to do it and when I clicked "Go Advanced" to check it, I got a log in screen and blew it away... Sorry....the short response will have to do...

LDO is a charactaristic (Behavior)- has nothing to do with Micro Controlled/microprocessor controlled etc...

Micro-Controlled implies some specialized programmable processor on board the voltage controller chip that lets you control what its doing prgramatically..... As opposed to hardwiring the controller and using a potentiometer (variable resistor...more on that later) to set the output voltage.

LDO is mostly an issue for "Linear Voltage Regulators" - google it - they've been around since the 70's.

Much less of an issue for "Switching Regulators" - google it - they've been around on chips since the mid 90's.

Also google "Buck Regulator", "Boost Regulator" and "Buck Boost regulators" which are all types of switching regulators... the concepts are not new, switching power supplies have been around for a long time, but getting them on a single chip with a microprocessor controler built in is only in the last 6-9 years....

Short and sweet: You want programmable Buck-Boost - found in ProVari, Darwin, MonkeyBoxx, EQ and others - they are more efficient, more accurate but more complex than linear regulators. To get percise results requires more work and generally a much deeper working knowledge of electronics than Linear Regulators. They are also the basis for PWM which can be achieved by varying the width of the pulses comming from a swiching regulator.

Linear regulators are inefficient and often regulated with potentiometers (Variable resistors- like the dimmer on your wall of the volume control of a Sony Walkman- sorry Buzz Fans) - not withstanding they do have thier uses where supplying a clean, percise, ripple free (not you ripple - we're talking signal ripple) is more important than efficiency (high end audio equipment comes to mind) . They are also much less complex and much easier to design effectively with a minimal understanding of electronics.


sidebar: There's an argument for Buck regulators over Buck-Boost with claims that stacking and using a buck regulator to get 6V is more efficient than Boost- I heard that from Caesar wrt the Precious LV2 - (a bar of alice's restaurant is in order). Not knowing the exact chip to look up the specs, I suppose it's possible- however if thats what was done with your device, then either the implimentation is flawed or the argument is wrong.

That's all i have time for tonight...

PS- in order to get what you want from your device- assuming its not defective, I think he should hire someone that knows what they are doing with electronics and redo the device to run properly off a single 18650 like others have already done. Seriously, stacked 700mAh? I'll keep my phidias with stacked LiFePO4's- and I'll buy yours too ;-)
 
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Shad0w

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no- no- no -no

Now you did it Shadow :) You brought the kids to a candy store and snuck out the back door....
;-)

So I did Jim... so I did :D My apologies.
I was trying to gie a "quick n' dirty" response to hopefully answer with a tiny bit of detail without adding to any confusion. lol My bad.

And yes most LDO type linear regs need to be selected very carefully.

Mister D, that reg has been on the market for a while and it is not at all bad in any way. I was not implying that.
It is a prepackaged ready to go solution that is very easy to implement and as such is a great choice for most who are just getting into the field of variable circuits in regard to e-cigs.
I would also like to apologize for my assumption that it was using and Linear Reg. It was a best guess without info. It is a switching reg so it is a bit different in its operation, so again, my apologies.

Jim, I look forward to hearing from you soon :)

Humbly,
Mario
 
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jimho

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hey, jimho! if you have time do you mind taking a look at the regulator specs and tell us what do you think of it?
3A Adjustable step down switching voltage regulator
there's a pdf file if you scrow down the page.

Quick look -

http://www.dimensionengineering.com/datasheets/DE-SWADJ3.doc
The efficiency graph starts at 8V for a 6V output. They are not telling you something- or more likely they are telling you that it doesn't drive 6V with less than 8V input.... I don't see info in the spec to tell if its appropriate for a pair of stacked LiIons. If there isn't a fixed drop out, maybe a graph of minimum input voltage vs output voltage with the adjusting screw set to the max. If you were running off a 12V car battery it would probably be fine for vaping- it certainly appears to be power efficient through a wide range of voltages. Is this what's in the RSM?


I was wondering, since you're one of the few who acutally managed to get an LV2- how does it work with stacked 18350's? Caesar gave me a lot of attitude when I asked him about it. I can't remember (if he ever told us) what he ended up doing in the final version to get to 6V.
 

jimho

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So I did Jim... so I did :D My apologies.
I was trying to gie a "quick n' dirty" response to hopefully answer with a tiny bit of detail without adding to any confusion. lol My bad.

And yes most LDO type linear regs need to be selected very carefully.

Mister D, that reg has been on the market for a while and it is not at all bad in any way. I was not implying that.
It is a prepackaged ready to go solution that is very easy to implement and as such is a great choice for most who are just getting into the field of variable circuits in regard to e-cigs.
I would also like to apologize for my assumption that it was using and Linear Reg. It was a best guess without info. It is a switching reg so it is a bit different in its operation, so again, my apologies.

Jim, I look forward to hearing from you soon :)

Humbly,
Mario

You sir are a gentleman and a scholar .....
& I owe you a call- tomorrow?
 

misterD

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I was wondering, since you're one of the few who acutally managed to get an LV2- how does it work with stacked 18350's? Caesar gave me a lot of attitude when I asked him about it. I can't remember (if he ever told us) what he ended up doing in the final version to get to 6V.

I've never actually put it through its paces, man. Never vaped on it for more than say a half a day at a time. I remember when I tested the voltage output for accuracy it was quite close to what it was supposed to be.
I never got the feeding system to work properly so I ended up using it with tanks and vapemate until i fully retired it after getting a Reo.
 

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OK - so I opened a can of worms... :blush:

I guess I need to do a little more research before I pose too many questions. I didn't realize that the observations I made would require a complex answer... I want to learn more, but it is kinda confusing trying to learn about this type of electronics by myself and with zero background in this field of study. It's kinda hard to know where to even start... BUT Mike from notcigs provided the following link (haven't read it yet) but I'm hoping it will give me some more background and ideas on where to start...:) Volts For Dolts: A Dummies Guide to Voltage Regulators I promise to read before I ask anymore questions!
 
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jimho

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OK - so I opened a can of worms... :blush:

I guess I need to do a little more research before I pose too many questions. I didn't realize that the observations I made would require a complex answer... I want to learn more, but it is kinda confusing trying to learn about this type of electronics by myself and with zero background in this field of study. It's kinda hard to know where to even start... BUT Mike from notcigs provided the following link (haven't read it yet) but I'm hoping it will give me some more background and ideas on where to start...:) Volts For Dolts: A Dummies Guide to Voltage Regulators I promise to read before I ask anymore questions!

Doesn't explain much....
try this one - may make your head spin a bit but it covers it all with an explaination of how they work:
http://www.national.com/an/AN/AN-556.pdf
 

VictoryNotVengence

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Deep drip well, variable voltage, top feed adapter, crazy light show.

Sound familiar?

Presenting the Fire Flower by Krimson Kustoms- $112 (flower decals and top feed adapter not included)
photo020110003.jpg
 

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