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regulated vs unregulated power supplies for "log vapes"

Discussion in 'Vapor Related Equipment' started by placetime, Jan 19, 2012.

  1. placetime

    placetime Well-Known Member

    Messages:
    912
    I'm not an engineer or electrician or anything like that, so someone please correct me if I'm wrong on any of this. :)

    My understanding is that power supplies can be either "regulated" or "unregulated", with the distinction being that "regulated" power supplies (somehow) ensure that the output voltage is precisely the number on the label (e.g., 12V), whereas an "unregulated" power supply sorta assumes that the voltage at the wall is 120V and ramps the voltage down by a factor of 10, resulting in output that is precisely 12V only if the power at the wall is precisely 120V (i.e., if the power at the wall is 110V, then an unregulated power supply would output only 11V, but a regulated power supply would still output 12V).

    And, since there is variability in the voltage that is coming out of the wall of different people's homes (sometimes it can even be different voltages on two different outlets within the same house), using an unregulated power supply makes it difficult to predict the actual output voltage that an end-user will see come out of a power supply.

    One of the factors that affects the temp of a "log vape" is the actual output voltage of the power supply used. I think that most (all?) log vapes ship with 12V "unregulated" power supplies (someone please do correct me on this if I'm wrong---do any of the log vapes normally ship with a regulated power supply?).

    So, it's tough/impossible to accurately predict what temp an end-user will see in their log vape, since the actual output voltage of the power supply is tough/impossible to accurately predict. I know that the range of variability isn't huge, but I think that it can be functionally significant in this context.

    So, this makes me wonder: why don't log vapes all come with regulated power supplies? Are they much more expensive? Or is there some other problem with regulated power supplies? And/or is there something beneficial about unregulated power supplies? It seems like the consistency (theoretically) of the output of a regulated power supply would be advantageous, imho, but what do I know? :2c:

    Anyone have any info about this?
    :peace:
     
  2. hazy

    hazy dreamer Manufacturer

    Messages:
    387
    Location:
    Australia
    I also wonder why they don't come with regulated power supplies. These days, most regulated power supplies are switchmode. The only benefit of unregulated supplies is that they are robust. They're just a transformer in a box. Switchmode power supplies are more complex and more prone to failure. However, switchmode power supplies have a number of advantages, being very efficient, lightweight, and inexpensive.
     
  3. placetime

    placetime Well-Known Member

    Messages:
    912
    Thanks for chiming in on this hazy! :) I also appreciate the info you gave on the Zap thread about this issue and about the AC vs DC issue ( http://fuckcombustion.com/viewtopic.php?pid=187667#p187667 ). Very interesting!

    Can anyone speak to the reliability of switchmode power supplies when used with log vapes? Unregulated power supplies are technically more robust, but it seems like the most common failure reported for log vapes is the plug wiring, not the power supply itself, so maybe reliability of the power supply is actually secondary to the quality of the wiring oustide of the power supply? So maybe "best" would be a switchmode power supply that has sturdy wiring/plugs?

    I know that the little power supplies used on some wireless routers are switchmode power supplies. I've got one leftover from an old dead Netgear router that is a switchmode 12v powersupply that I've used some with my PD, but I didn't notice until now that it says "switching adapter" on the label. I have only used it a little with my PD (worked without issue), but it worked fine for years with a wireless router (then the router itself died). I wonder what the difference is in power requirements for a log vape vs. a wireless router, and how that might translate into reliability of using a wifi router power supply hooked up to a log vape 24/7. Maybe I should plug this one in and start using it 24/7 and see what happens. ;)


    Note: I know that "log vape" isn't a very specific term. In this context, I'm only counting the wooden "log vapes" that all use the same resistor as a heater. This includes the PD, MZ/CRZ, UD, TT, HI, WZ, and possibly some others that I'm forgetting; but this doesn't include the OCD or EV-1 (this is definitely not meant to be any sort of commentary on the quality of the OCD or EV-1).
     
  4. hazy

    hazy dreamer Manufacturer

    Messages:
    387
    Location:
    Australia
    Although I said that "these days most regulated power supplies are switchmode", I think you would be hard pressed to find one that isn't. And it's not just wall warts I'm talking about. Televisions, computers, and all kinds of electronic equipment have switchmode power supplies inside them. It's a proven concept that works well and is quite reliable. Having said that, when these appliances fail, it's often a blown capacitor in the power supply that is the culprit. I know this because one of my friends was a television serviceman.

    Transformers are old school. You can easily tell if a power supply has a transformer in it because it will be heavy, and it will most likely be old. I think they are getting pretty rare. Certainly you can use any power supply for the PD, it just needs to be 12V (more if you like it hotter) and capable of delivering at least 1A. If your Netgear power supply has worked so far, then it should continue to do so. Switchmode power supplies are designed for continuous operation at high loads.

    You are probably correct about unreliability often being caused by worn leads. When using a PD, the lead coming straight out of the vape gets bent and moved around a lot. It's likely that the "quality" power supplies that come with these vapes have thicker leads than the cheap Chinese ones that retail on eBay for $5 or less. I've got a power supply with a right angle plug on it which seems to protect the lead from this kind of movement, although funnily enough it is an ancient phone charger with a transformer in it - big and chunky but makes my PD run nice and hot :brow:
     
  5. placetime

    placetime Well-Known Member

    Messages:
    912
    "If it ain't broke, don't break it", as they say. ;) I'm also still using unregulated power supplies myself (except for playing a bit with that Netgear one), because they are working just fine for me.

    This issue just makes me curious, though. I googled a bit, and learned a little more than I knew before about unregulated vs. regulated power supplies. I have some other questions that maybe you can answer, hazy? :) Or anyone else for that matter? I've been surprised that, given the liveliness of the log vape threads, more people haven't joined in this conversation already.

    One question is about safety. Are there any safety differences (in the log vape context) between using regulated/switched vs unregulated power supplies? Are failures more problematic in one than the other?

    My second question might be trickier and/or demonstrate more clearly my lack of understanding of electronics. ;) I came across this bit on a page about regulated vs unregulated power supplies:

    "The first important concept to understand about unregulated DC voltage output power adapters is that they are designed and rated to produce a particular voltage at a particular maximum output load current. The output voltage of an unregulated power adapter will decrease as the current provided by the adapter output to the load increases." ( Selecting an AC-DC Power Adapter )

    I seem to recall reading somewhere on one of the logvape threads that as the resistor inside gets hotter, the load drops. Does this mean that functionally (in a log vape context), as the log changes temperature, the voltage and current being supplied by an unregulated AC/DC power supply vary until some sort of equilibrium is reached? If so, it seems that as a log is used, the temp changes, so an unregulated supply would change it's output in response? It seems that at that point, an unregulated power supply would either be better than a regulated one because it would boost up the power output to push back harder to try to get back to equilibrium (vs the constant output of a regulated one), OR, the unregulated power supply would be worse (than a regulated one) because the temp change would cause the power supply output to decrease, thereby taking longer to heat the log back up. I'm not understanding this fully enough to be able to predict which way it would go, if at all. :p Either way, though, I'm guessing that it might still be better to have the predictible consistant output of a regulated supply. :2c:

    Comments anyone?

    :peace:
     
  6. hazy

    hazy dreamer Manufacturer

    Messages:
    387
    Location:
    Australia
    I also expected that there would be more informed discussion about power supplies, considering how critical they are in achieving the final result. People seem to rely on anecdotal evidence and hearsay to draw their conclusions. I suppose most people aren't that interested in technical stuff. I know it can get boring.

    I didn't know the answer to your question, so I looked it up. According to this wikipedia article about switchmode power supplies
    http://en.wikipedia.org/wiki/Switchmode_power_supply
    the SMPS is upon failure more likely to damage equipment than a linear or unregulated power supply.

    It is true that the output voltage of an unregulated supply will sag as more load is applied. The rated voltage of the power supply is at full load, so at lower loads the voltage will be higher than what is printed on the label. If you have a voltmeter and measure the output of a 12V unregulated supply when it's not connected to anything you will find that it is a lot higher than 12V. I measured mine and it was putting out 17V with no load.

    The value of the resistor does change as temperature changes, but I don't think it is by a significant amount. According to the Ohmite spec sheet, the resistance increases by 30ppm/C, which I think results in the resistor's value increasing by about 0.1 Ohm. Not much really. To be honest, I don't know the exact dynamics between the power supply and its load under these circumstances, but we are talking about quite small amounts here.

    The main thing is whether the power supply you are using is giving you the results that you are happy with. I'm in the process of getting a 0-15V variable power supply so that I can dial up any voltage I want.
     
  7. placetime

    placetime Well-Known Member

    Messages:
    912
    I've been away for a while--thanks again for all the input hazy (including on other threads...). Given what you've said and what I've heard from others, I wonder if the situation is that it's somehow easier/simpler to produce cheap *and* reliable unregulated power supplies than it is to make cheap *and* reliable regulated power supplies?

    Underdog Dave used to offer (and still uses something like it himself on his workbench, I believe) an optional variable-voltage regulated power supply (no longer offered, but not due to reliability). But Dave normally includes unregulated power supplies with Underdog vapes. I think that Toasty-Top/Heat-Island Alan only sells regulated power supplies (including a variable-voltage one). Whereas Rockzap Rick (who has been doing this the longest of the three) only sells unregulated power supplies.

    So, this still leave me a little bit confused. :rolleyes: One of these days I need to go ahead and get a better multimeter and probably a variable rate regulated power supply too. :cool:

    :peace:
     
  8. vap999

    vap999 Well-Known Member

    Messages:
    207
    A variable power supply (by definition, regulated) is nice, but are inefficient, not very portable and not really needed. Why not consider a 13-14 volt power adapter and use this with most any solid-state 12-14 volt (LED, car/RV/boat) dimmer switch, costing about $10. And if you see a need for digital display (here amps, with these dimmers cutting down the current, not voltage), patch in your multi-meter.

    Otherwise, I favor regulated power supplies (used with solid-state dimmer switches). Besides always putting out constant voltage, these seem much safer and better designed. I've had unregulated (the plug-in at the wall-type) adapters smolder, meltdown, etc.; and some that do not shut-down when shorted-out. The newer regulated power supplies run cooler and have instant and more reliable short circuit detection (cut-off). This could be among the reasons why computer monitors are powered by regulated power adapters.
     
  9. placetime

    placetime Well-Known Member

    Messages:
    912
    Thanks for the input vap999. :) Can you recommend any particular 13-14 volt regulated power supply and/or a particular dimmer switch?

    Another question--I know that unregulated power supplies output different voltage whether it's under load or not. But that's not the case with regulated power supplies, right? I just plugged a multimeter into a regulated power supply (no load) and it shows 12.3 volts (rated as 12v on the label). It's not going to drop lower than that under load, right?

    Also, is there any way to measure the output of an unregulated power supply under load besides using something like the following part and touching the multimeter probes to the screws?
    http://www.parts-express.com/pe/showdetl.cfm?Partnumber=335-330

    :peace:
     
  10. hazy

    hazy dreamer Manufacturer

    Messages:
    387
    Location:
    Australia
    The regulated supply might drop a little under load.

    I use the same part for measuring voltages under load, but I have it connected to a socket so that I can just plug any power supply into it without needing to cut wires. The socket I use is a matching screw terminal part, although something like this is just as good as long as you don't mind doing a bit of soldering:
    http://www.parts-express.com/pe/showdetl.cfm?Partnumber=090-481
     
  11. OhTheAgony

    OhTheAgony here for the chicks

    Messages:
    2,906
    Location:
    The Flatlands
    I'm a bit to rushed right now to read this entire thread, but I've been having good results with my UD combined with this 13,8V PSU so I figured I just leave it hear as quick contribution to this thread.

    The plug on the adapter fits the UD perfectly and as far as I know the PD, CRZ, TT and HI all use the same plug so it should fit those as well. When in doubt, check the picture with the plug dimensions in the ebay add.

    This PSU makes my dog run hot as hell and I had to move the screen back a little to prevent combustion, so it may not be usable with all logs mentioned above depending on what stems you use with it. I also don't recommend leaving a vape on this PSU for 24 hours. I've done a couple of test sessions up to 8 hours straight, and based on those I think it's best to stick to 4 hour sessions at the time at most to prevent overheating. Your results may vary depending on the size and on what wood type your log is made off so careful testing is recommended and at your own risk (duh).
     
  12. placetime

    placetime Well-Known Member

    Messages:
    912
    Thanks for the tip hazy. What a great idea to make one to go "inline" like that so no psu wire-cutting is necessary. I should have thought of that! Fortunately I haven't actually cut anything yet.

    Thanks for the suggestion OTA. :) Do you happen to know whether or not that's a regulated power supply?
    :peace:
     
  13. OhTheAgony

    OhTheAgony here for the chicks

    Messages:
    2,906
    Location:
    The Flatlands
    I have no idea man, all I have is the info on the adapter and in the add. Is there some kind of symbol for that perhaps?
     
  14. vap999

    vap999 Well-Known Member

    Messages:
    207
    I use "12 Volt DC Single Color LED Dimmer." model LDP-2A from Superbrightleds.com. See http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=/specs/ldp-2a_specs.htm This costs $9.95, but I presume the same thing can be found on Amazon, Ebay and other sites for less. It's just a PWM solid-state dimmer switch, made to be used with 12-14 volt systems (cars, truck, RV, boats, etc), with this company selling it for use with LED lighting systems (surely more challenging loads than a log vaporizer). At 12-14 volts, that means the current should not exceed about 2 watts to stay within specs. The typical log-type vaporizer generally operates at less than 1 watt, so this switch will be well within its operating range.

    These dimmer switches work the same way as do familiar wall-mounted dimmer switches -- by linearly reducing the current (amps; amount of electron flowing), not affecting voltage. [They divide the current flow into 1000s of pieces/second, and then vary the percentage of on-off-times/second]. I've used mine continuously for years with both AC and DC and both regulated and unregulated power supplies. The power supply used with these and related dimmers is irrelevant (for electronic circuitry-lacking log vaporizers), as long as it's 12-14 volts and has at least much amps rating as the vaporizer (to not exceed consuming/using 24 watts, the important limiting spec, with watts (power) = volts x amps).

    Using one of these or similar dimmer with any 13 or 14 volt power adapter (with the correct/usual size connector), which are available online, should allow full (0-100%) reproducible (set it to the same spot, get the same amount of power/heat) analog-adjustable power (ambient heat) setting for most any conventional log-style vaporizer.

    This approach, using a slightly higher (but still in allowable range for vaporizer) voltage (13-14 volts) power supply with a simple reducing dimmer switch is so simple, basic, etc., I've always wondered why FC log vaporizer owners and manufacturers haven't universally adopted this!
     
    OhTheAgony likes this.
  15. OhTheAgony

    OhTheAgony here for the chicks

    Messages:
    2,906
    Location:
    The Flatlands
    That's a pretty cool gadget man, thanks for the tip!

    I think it calls for a picture for the more visual minded people:


    [​IMG]


    I ordered one here to try with my 13,8V PSU for just 5 euro's if anyone's looking.

    Could these work as well perhaps?
     
  16. Abysmal Vapor

    Abysmal Vapor Shaman of The Pyramid of Orlin'Malah

    Messages:
    2,167
    Location:
    7th heaven - 666th pit
    Don't u expect running on some problems running dimmer rated for 12 V on a 13.8 V PSU ? :) Just curious not that i know shit about electricity ..
     
  17. OhTheAgony

    OhTheAgony here for the chicks

    Messages:
    2,906
    Location:
    The Flatlands
    I payed 5 euro's and 78 cent for it including shipping, I'm willing to risk the 2 volts for that. If it melts it melts, but if not I'll have a pretty cheap portable variably PSU all of a sudden :)
     
  18. WatTyler

    WatTyler Revolting Peasant

    Messages:
    1,285
    Location:
    57°N 06°W
    I'm really confused- Like Abysmal I have quite a rudimentary understanding of electronics. Do you mean amps rather than watts where I've highlighted? That might make sense as I understood the log's resistor to be 5W, overdriven to about 8W, rather than less than 1W. It could also explain where the 24W limit figure came from?
     
  19. placetime

    placetime Well-Known Member

    Messages:
    912
    edit: was gonna comment on wattyler's post, but maybe i'm confused now... :ko:

    more edit so I don't post back-to-back...

    @hazy--thanks for the info you posted in the UD thread about the sensitivity of that dimmer
    @OTA--looking forward to hearing if you have the same experience with the one you ordered

    I wonder if some sort of inexpensive dimmer that restricts voltage exists. Maybe that would have a less-sensitive adjustment?
     
  20. hazy

    hazy dreamer Manufacturer

    Messages:
    387
    Location:
    Australia
    Yes he means amps. Anyway, I found the dial on this dimmer to be too sensitive.

    I've been using a tattoo power supply for the last few weeks. It's similar to this. I paid $15 for mine, but shipping was really slow, it took about a month to get here. It seems to work well. It uses a mono headphone plug to connect, so I had to make up a cable with the headphone plug at one end, and a 5.5/2.1mm DC plug at the other end. These power supplies are intended to be used with a foot switch, which is why there are two sockets on the front panel. Because I want it switched on full time, I took another headphone plug and wired the terminals together, and leave it plugged in. It doesn't matter which sockets the plugs go into; you can swap them around and it makes no difference. I found the digital display to be accurate to within about half a volt. The voltage adjustment dial is quite firm, so I don't need to worry about bumping it. The supply is stable; whenever I switch it on it stays at the same output I used last time.
     
  21. u bwade wunner

    u bwade wunner Well-Known Member

    Messages:
    652
    Location:
    cloud nine
  22. OhTheAgony

    OhTheAgony here for the chicks

    Messages:
    2,906
    Location:
    The Flatlands
    Yeah, I'll let you guys know if mine is just as sensitive as the one Hazy got when it gets here.

    I also ordered one of these btw:

    [​IMG]

    ebay link

    So I should be good anyways.
     
  23. hazy

    hazy dreamer Manufacturer

    Messages:
    387
    Location:
    Australia
    U bwade wunner, if it's anything like mine, that supply should work well. The only thing I'm concerned about is the current output, as that is not mentioned in the ad. Should be ok for the vape though, as I think the tattoo guns have a higher current requirement. It will certainly be a regulated supply. For the cable you can get one of these and cut the springy clip end off and replace it with a 5.5/2.1mm plug. Otherwise you can get the parts from Jaycar or similar (you're in AU, right?) and do the whole thing yourself. Remember you will need another headphone plug as I mentioned above.

    OTA, that thing is serious overkill! It's rated for 15A. I kind of like it though... :brow:
     
  24. u bwade wunner

    u bwade wunner Well-Known Member

    Messages:
    652
    Location:
    cloud nine
    OTA
    thats a beast of a thing.Takes me back to the old 27mhz CB days.love how you can adjust the amps coming out of it too.nice badass lcd display too

    Hazy
    Yup I had a look at similar tattoo PSU's on ebay and they all were 1.5 -2A so i thought for 14 bucks why not

    Judging from your e experiences with a similar unit.I wont just be able to ignore the footswitch socket,I was gonna use the footswitch cable as my power lead,cut the footswitch off and solder a 5.5 for my log instead and stick it it the output power socket.

    So will I have to complete the circuit on the footswitch for the unit to work?

    Maybe As an option I can always pop the lid off the PSU remove the footswitch and solder the power leads together inside the PSU too right? pop a rubber plug where the footswitch socket was and tape up the leads inside to stop them shorting on the casing..should work I think

    these supplies are great and with variable led readout should be ideal for logs.I turn my temps down between hits to save power and to protect the log a little from heat.I keep it just high enough for essential oils.what i love about logs is if you re handy they are with you for life.Fuck yeah!
     
  25. OhTheAgony

    OhTheAgony here for the chicks

    Messages:
    2,906
    Location:
    The Flatlands
    Yeah, I figured it should be heavy enough to feed all the logs I'll eventually hook up to it all at once :lol:

    That picture makes it looks pretty ginormous, but It's suppose to be quit modest in size though...or so I hope :uhoh:
     

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