Has anyone considered using one of these circuits in 3D printing? Just curious.

Has anyone considered using one of these circuits in 3D printing? Just curious.

Originally shared by William L. DeRieux IV

For anyone who is interested I created this simple circuit using an LM317T that can be used to drive 2 to 4 ohm e-cigarette coils such as the commercial offerings from blu-cig, Vuse, or any manufacturer as long as the coil is 2 to 4 ohms.

For example the Vuse Vibe Solo has a 3V battery and uses 2.5 ohm coils.
The current draw is: 3V/2.5ohms = 1.2A with a power draw of 3^2/2.5 = 3.6W.

R2 can be decreased to lower the output voltage and, conversely, R2 can be increased to increase the output.

However, the datasheet for the LM317 states the maximum output current is 1.5A so that must be taken into consideration when setting the value of R2.

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On a side note:

On these vuse cartridges there are three terminals and they are laid out like this:
( x ( + ) x )

The two terminals on outer perimeter are for delivering power to the coil to produce vapor.
The center terminal is the one that enables communication between the cartridge and the battery.

I would bet that if you removed this center terminal that you wold be able use the cartridge indefinitely with a Vuse Solo battery until the cartridge ceases to funcation.

right now I have one of these cartridges jerry rigged to an Eleaf IStick 30W running at 5W and have not had any trouble – although I have only used 2 cartridges so far.

You could connect a battery with a switch to the two outer terminals and do the same.
For the power source I would recommend: 2x AA batteries = 3V and if the cart is 2.5ohms you would be running the cart at ] P=V^2/R = 3V ^ 2 / 2.5 ohms = 3.6 watts ] [ I=V/R = 3V / 2.5 ohms = 1.2 amps].

A single AA cell (at 1.5V) can deliver 2500 mAh or 2.5 Ah if you were to run at 3.6W /1.2 A as above constantly you would get 2.5Ah/1.2A or ~2 hours of usage before you needed to replace or rechange the batteries since the coil won’t be constantly energized for that 2 hours.

2.5 A/hour = <1 mA/second and for 3 seconds it totals to a draw of ~ 2 mA.

If you take a puff for 3 seconds every 10 minutes ( a total of 60min/10puffs or 6 puffs per hour ) you be pulling ~12 mA per hour.
12 mA / hour = 12/1000 Ah = 0.012 A/hour.
2.5Ah / 0.012A/hour = 208.333

That means that a AA battery providing 2.5 Ah would last for at least 200 hours under these conditions – assuming that my math is correct, but the point is that you will at least get a very long runtime.

http://jeelabs.org/2012/11/26/watts-amps-coulombs/

Linear regulators have a very bad efficiency. I wouldn’t use it for more than a fan or some LEDs, but these I can drive much easier with a PWMed Mosfet.

I am not sure how anything 3D printing related can be considered efficient else than maybe cost efficient. Energy efficient…I do not think that describes our setups. Especially not if a heated bed is involved. You have a good point on controllability though.

I mean the linear regulator will just burn the difference between Vin and Vout as heat. If you regulate down from 24V to 5V and draw 1A on the 5V side, the same current will be drawn on the 24V side. In this case you are using 5W but the regulator has to turn 19W to heat.

@ChPech that sounds bout right.

@NathanielStenzel ​ for what do you want to use it??? Lm317 in any form without an additional transistor cant get anything to work but some leds or a raspberry pi…

@VolksTrieb if that circuit actually works for an e-cig, it would probably work for a custom hotend circuit too.

Yes, but the point is that it would produce way more heat in the circuit than at the actual hot-end!

@Nick_Johnson ​​ not on an ATX power supply that has 5v and 3v outputs available.

Then you’re still wasting 2/5ths of your energy in the regulator, assuming your hot end drops 3 volts.

This is just an ordinary linear regulator circuit. Existing switching regulator designs are far more efficient, and that does matter - because it’s less waste heat to dissipate.

@NathanielStenzel afaik lm317 goes up to 2.5 amps. 5V times 2.5A are what 12.5W? Lol yeah for a small ezig that doesnt even really vape. And you have 1.25V less cause the lm317 has that as dropoff and referencevoltage. Sure go ahead instead of just using a fuckin switching mosfet which works…

@VolksTrieb not enough wattage to be useful for filament melting. Noted.

@NathanielStenzel my first printer had a 20W cartrige, coulnt even handle fast prints or a coolingfan. Sry dude, your wont get good results under 40W

http://www.ebay.com/itm/LM2596S-DC-Buck-Step-Down-Adjustable-1-25-35V-Power-Supply-Regulator-Module-/132012991970?_trksid=p2349526.m2548.l4275 will do a good job of producing regulated adjustable voltage from 12V at reasonably high efficiency, for $4, shipped. If you want constant current, there are some switchers that can do that as well. (I design LED drivers, that are constant-current devices capable of driving 0.5 to 40A, depending on the model, at 90% efficiency.)

@John_Bump thanks for the more appropriate circuit link.

I’ve used the 2596’s quite a bit and they do a really good job, though I don’t think they can handle the 2.5A you were asking about, but I think there are similar regulator modules on ebay that will handle that.