Does anyone actually understand what the mini 30 is doing in DC mode...the manual is pretty vague about this, how is low voltage handled...the mod will only fire as low as the current battery charge? Then in PWM mode low voltage is achieved by pulsing?
PWM vs DC mode Sigelei Mini 30
- Thread starter mesamay2003
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Yep... in DC mode, the chipset is bypassed, allowing the atty to run directly off available battery current... which permits a lower net resistance than otherwise permitted by the chipset.
Edit: In DC mode, you'll need to know your battery MCCD (maximum continuous current discharge) value, then run the Ohm's law formula of V ÷ Ω = C (amperage) to ensure you've enough continuous current for the net resistance used.
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That's what I thought...how does bypassing the chipset affect the figures shown on the display?
It doesn't really bypass it, you can still change your wattage. Anytime your set above the battery voltage, it automatically changes to DC-DC. PWM is only used if you need to go below..
OK an update.. Apparently what I said about it kicking into DC mode above 3.7v (which I've read several times on this board, and figured was correct) isn't true. Was playing around with it at work today, was running at 4.4v at 13w.. Switched it to DC-DC and saw the voltage go up to 4.6 (DC mode always runs .2v higher). Switched it back to PWM and voltage dropped back to 4.4.. So it looks like you can PWM all across the range. But DC-DC can't buck below like 3.6v. Maybe when you drop it, it automatically kicks in PWM, but it definitely doesn't automatically turn on DC-DC once you go higher than the batterys voltage..
Ok, so now I am confused...in my case I like to run my subtank mini with the .5 occ coils at about 22w, if in PWM it sets the voltage to 3.4 volts and I can tell it is pulsing...switch to DC and still at 22 watts, it switches to 3.6 volts, but I can tell a difference in that it has a smoother firing...how should I be running this thing, as I am not sure what happens in DC mode as the battery charge weakens...
If you like DC better than use that.. Pretty much a personal preference. I personally can't tell of any 'pulsing', I just leave mine in PWM mode, set it and forget it..
I guess what I want to know, is if the mod is still running in the stated wattage on the screen, if the voltage is changing over PWM mode...anyone know??
Sounds good...............But it is incorrect.
DC-DC Mode is capable of running Battery minimum to MOD design Maximum.
DC-DC cannot cut power below Battery voltage so, even if the screen reads 7w it may be much higher,depending on Coil resistance.
PWM is designed to Buck(cut) voltage and can reduce to the proper wattage setting.
Since Both IPV mini 30w and Sigelei 30w use the same YiHi XS130 chip I would think Both would auto switch if set to PWM. IPV mini Does auto switch.
An oscilloscope is needed to read the output properly to test and confirm.
Sounds good...............But it is incorrect.
DC-DC Mode is capable of running Battery minimum to MOD design Maximum.
DC-DC cannot cut power below Battery voltage so, even if the screen reads 7w it may be much higher,depending on Coil resistance.
PWM is designed to Buck(cut) voltage and can reduce to the proper wattage setting.
Since Both IPV mini 30w and Sigelei 30w use the same YiHi XS130 chip I would think Both would auto switch if set to PWM. IPV mini Does auto switch.
An oscilloscope is needed to read the output properly to test and confirm.
Not disagreeing, but why would anyone use DC-DC if it eliminates adjustment below battery voltage?...why not just use a mech mod - or did I miss something? I suspect it has something to do with this, but not sure what this means exactly:
"DC-DC Mode is capable of running Battery minimum to MOD design Maximum."
That's what I'm trying to figure out, it seems to me that if running in DC-DC mode, the display should show the actual voltage being used, and recalculate the wattage accordingly...
New right?
DC-DC BOOST is what is required for a SMOOTH output ABOVE battery level. Implemented for the user wishing to run higher wattage devices. The ability to perform like a Mechanical mod being able to run much lower resistance coils and maintain steady output.
Exactly what the mod does in DC-DC - Reads/Calculates on Voltage available - Wattage on screen may be incorrect but wattage delivered is correct.
This only for wattage Below Battery level in DC-DC mode. Wattage request at/above battery level will be correct.
Screen reading is the REQUESTED Wattage.
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Ok, so on a freshly charged battery, with my subtank mini running the stock .5 occ coil, I like to run at 22 watts...in PWM mode set to 22w, I get the .5 ohm resitance at 3.3 volts, which is close at 21.78 calculated watts...in DC-DC, voltage on display jumps to 3.6, and that calculates out to 25.92 watts yet display still reads 22 watts?
Um, not quite boss. But a lot of your answers are not that well written to be honest. Wattage below battery level?...what the heck is that? I'm wondering if you know just what the heck you're talking about.
I have a background in electronics so ohms law is like kindergarten to me, and half the time don't know what you posting.
Sorry for being blunt, but that seems to be the way you address others here with your condescending tone.
I am thinking about buying one of these devices, but now I am having trouble understanding DC-DC mode. This is probably a dumb question, but if this a "mech mode" does this mean that this device can deliver above 30 watts in dc-dc mode?
That's what I thought, but apparently being a n00b, I have gravely misunderstood the function of this mystery mod. 
All I know for sure is that when I set mine to DC-DC fully charged it fires waaaaay too hot (Kanger Subtank Mini and .5 ohm coil) for my taste. If I switch to PWM mode it's fine and seems to behave like a true regulated mod.
Don't be afraid of it, it actually works OK in PWM mode (for a cheap box mod).
All I know for sure is that when I set mine to DC-DC fully charged it fires waaaaay too hot (Kanger Subtank Mini and .5 ohm coil) for my taste. If I switch to PWM mode it's fine and seems to behave like a true regulated mod.
Don't be afraid of it, it actually works OK in PWM mode (for a cheap box mod).
well i would be buying it for the form factor, I already have the Sigelei 150, but if this thing can fire above 30 watts in dc dc mode that would just be a huge plus for me and I would use RDAs on this as well. Still can't find any info on this.
No, DC-DC is not a "mechanical mode" its still regulated, and no its never going to put out more than 30w.
Okay, you understand Ohms law. That may be your problem in understanding how the mod works. You can quickly calculate what the watts Should be according to Resistance and available voltage.
Now you have to get in tune with the way DC-DC functions and PWM functions.
I did not call you a NOOB. I asked if you were new, as in - new to Regulated Mods?
If you have a back ground in electronics, I'm not sure why you don't understand a DC-DC system is capable of producing output at or (boosted) above battery voltage level, regulating output to a flat DC signal.
I have not seen any DC-DC devices listed that will regulate Below Battery voltage level. (Not far below anyway)
DC-DC, .5ohm - should not output below 30 watt level
PWM - Set to desired wattage
DC minimum vs. Voltage Bucking - Pulse Width Modulation. Pulsing available voltage to avoid exceeding requested wattage.
PWM does not actually reduce voltage. It pulses voltage at a calculated rate for a given setting.
off is always off
On is always at a factory set peak
Control is time off / time on
Being an Auto technician most of my life, I can only tell you what it does, not the (Technical) electrical terminology.
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