Comment by londons_explore
13 hours ago
I see lots more cost-cutting corners they could take...
Vapes are probably made in enough quantity to warrant custom silicon. Then the mosfets and charge circuit could be on the same die. It could be mounted COB (black blob).
They could probably use a single 'microphone' (pressure sensor) and determine which setting based on a photodiode.
The PCB's could be replaced with a flex PCB which integrates the heating elements (Vegetable Glycerine boils at 290C, whereas Polyimide can do 400C for a short while). Construction of the whole device can then involve putting the PCB inside the injection moulding machine for the cavities, eliminating all assembly steps, joints and potential leaks, and reducing part count
> Vapes are probably made in enough quantity to warrant custom silicon
Not when the MCUs might cost a penny and the other parts aren’t much more.
Putting high power electronics and analog into the same custom silicon as a custom digital logic is nontrivial. They’re made on different processes.
But you need very very little digital logic... The same kind of quantity to do the little power indicator LED's on a battery bank (which are charlieplexed btw), and thats done in the same ASIC that also has the 5V boost power supply (multi-amp gnd isolated n type mosfet) and charge circuitry involving voltage references and laser tuned comparators, and sometimes negotiates USB-C PD as well (needs an internal ROM). And the whole thing needs to be really cheap and with a standby current of uA's.
As long as you aren't interested in multi-Mhz operation, combining the rest at very low cost isn't too tricky.
If simplicity is the goal, then sure: Maybe spinning up a custom part can become useful.
But simplicity isn't always the goal. I have a throwaway vape here with a color LCD screen that plays full-motion animations.
To be sure, that's not necessary at all. But this functionality does exist, and people do buy them.
IIRC, they're said to use a 48MHz Cortex M0 part. More information here: https://github.com/ginbot86/ColorLCDVape-RE
> But you need very very little digital logic...
Right, which they already get from a $0.01 MCU
Combining an MCU and multi-amp power transistors into the same package is expensive.
I love the term “high power” even though we are talking maybe a watt or two when that bad boy’s element is doing its thing!
I mean relatively it absolutely is high power. The quiescent current on that thing has to be microamps…
It’s just funny because to me “high power” is hundreds or thousands of watts. Like an incandescent light bulb or a hair dryer. Or at least it was until I started tinkering with battery powered microcontrollers and doing math to realize exactly how long an 18650 might power a small strip of individually addressable LED’s…
“High power” is a very relative term :-)
> I love the term “high power” even though we are talking maybe a watt or two when that bad boy’s element is doing its thing!
Your estimate is 1-2 orders of magnitude too low. Small vapes pull a couple amps, as I understand it. Larger vapes can pull over 50-100W. The modded ones into the 200W range. These things can use more power than most CPUs for the brief moment they're on.
The power draw is so high that vape fans compare and review batteries to show which ones can sustain the most power output.
It's an unexpected boon for those of us who use batteries for other things: The vape craze has made more high current batteries available with a lot of user contributed test data.
Vape wattages are more like 15 watts, which is an awful lot for a battery smaller than the tip of your pinkie! I believe the power density (not energy density) of those batteries is market leading.