I have a vape device with a mod that lets me configure the power I want to operate it with and also as an additional setting that is called vape strength which can be set to soft/medium/hard.

When operating it on soft it generates just medium amount of light vape. On hard it tastes most of the time burnt.

So my question is, what electrical unit can influence this options, given that the power is set fix?

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    \$\begingroup\$ Why do you believe the power (to the heating element) is fixed? \$\endgroup\$ – Ron Beyer Jan 9 '18 at 15:47
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    \$\begingroup\$ A valid answer to the question in the title, is Emissivity. \$\endgroup\$ – MrGerber Jan 9 '18 at 16:21
  • \$\begingroup\$ @RonBeyer: Because I can set the power myself. and If I set it to i.e. 22Watt, I assume it will be 22Watt fix. \$\endgroup\$ – dhein Jan 9 '18 at 16:25

It could be monitoring temperature by the PTC resistance of the heater and altering the duration of power or total energy. I have seen expensive Vapes with many digital parameters on an LCD and this is how I imagine they have control over these variables.


I think soft and hard referring to slew rate power in first second makes most sense to me which affects volume of smoke but not final temp.

How that ramp up is controlled may be non-linear in terms of power , temperature and taste so finding the right thermal profile is key to the recipe by trial and error and shared experiences.

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  • \$\begingroup\$ Well, mine was overall 250€ I dont know if that counts as expensive one, but it has many parameters. And especially it heats when ever and as long I hold the trigger by the set power. So there is no parameter I could think of, being able to side kick in. Thats why I asked here. \$\endgroup\$ – dhein Jan 9 '18 at 16:39
  • \$\begingroup\$ I suspect it must be temperature regulated for equivalent strength. I've seen them with actual temperature settings. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jan 9 '18 at 16:55
  • \$\begingroup\$ Well mine displays the heat, and it doesnt really appear regulated, as I have to keep an eye on it my self \$\endgroup\$ – dhein Jan 9 '18 at 16:58
  • \$\begingroup\$ It is best to read the website datasheet and user manual and join their forum e.g. aspirecig.com/aspire-kits/aspire-kits487.html There must be some differences with power and temperature to define hard soft flavours. aspirecig.com/downloads \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jan 9 '18 at 17:59
  • \$\begingroup\$ Ok so ur answer is there is no other Unit (what I wondered too), and they have to work somehow around the user input? \$\endgroup\$ – dhein Jan 10 '18 at 2:37

Power is most likely not fixed. From your description, it seems that power is at least one of the parameters that is altered as a result of the soft/medium/hard setting.

The heater is most likely a nichrome element. This is often used for electrical heating since it has relatively high resistivity and can handle glowing temperatures.

The power dissipated by a resistor is proportional to the square of the voltage and the square of the current. There is probably a switching power supply in your device. If this were a laboratory instrument, a processor would probably continually measure the voltage and current, then adjust the pulses duty cycle to regulate the power. In a cheap consumer device like this, maybe it regulates the voltage. It might just be pre-set to three different PWM duty cycles.

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  • \$\begingroup\$ I have found FeCrAl-alloy to be a common material for E-cig heaters, over NiCr. (I have spent quite some time investigating FeCrAl-alloys some time back (Not for e-cigs) ) \$\endgroup\$ – MrGerber Jan 9 '18 at 16:16
  • \$\begingroup\$ @MrGerber: Yes, that's also a possibility. \$\endgroup\$ – Olin Lathrop Jan 9 '18 at 16:20
  • \$\begingroup\$ Not that it makes any significant difference, technically. I just thought it might be relevant. \$\endgroup\$ – MrGerber Jan 9 '18 at 16:21
  • \$\begingroup\$ My device is actually a RBA that means I build the heating element my self, and I just used typical stellwire for it. Also yeh, the power is not fixed by it self, I can set it and would simply assume, when I set it to 22Watt, that it will be 22Watt fixed, as it also isn't showing any change in power when changing the soft/med/hard option. \$\endgroup\$ – dhein Jan 9 '18 at 16:41
  • \$\begingroup\$ So you say its most likely the PWM that changes acordingly to that setting? \$\endgroup\$ – dhein Jan 9 '18 at 16:42

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