# 24v power supply + 12v heater? **URL:** \ **Category:** Hardware\ **Created:** [April 9, 2014, 6:31am UTC](https://forum.lulzbot.com/t/24v-power-supply-12v-heater/553 "2014-04-09T06:31:23Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Epicfail](https://avatars.discourse-cdn.com/v4/letter/e/96bed5/32.png) [@Epicfail](https://forum.lulzbot.com/u/Epicfail)\ **Post date:** [April 9, 2014, 6:31am UTC](https://forum.lulzbot.com/t/24v-power-supply-12v-heater/553/1 "2014-04-09T06:31:23Z")
Hi again Lulzbottians, I’ve been accruing my components for my lulz build and after trying to use what I already had on hand, I ended up buying just about every single solitary part from the Lulzbot store, asside from the machine itself. One thing I havent taken from the store is thr 24v silicone heater, not just yet anyway. I had already purchased a similar sized heater, but it requests 12v 20a… as compared to the 24v 10a. The -basic math- i have run across is that v_a = w er, P=I_V … and both silicone heaters basicly turn out to be 240w power consumption. Under this am I to assume I can likely power my current 12v 20a silicone heater under the same or similar conditions as the 24v 10a silicone heater? ( Im using the 24v 15a power supply from the Lulzbot store) Any technical know-how here would be awesome. Honestly I wish I had just bought the Taz, it would have saved me time, but I’m so close to being done I can taste it. I just need that last bit to cross the gap. Then once I’m selling commissions again I can just buy a Taz like I should have. ---
**Author:** ![bam](https://avatars.discourse-cdn.com/v4/letter/b/34f0e0/32.png) [@bam](https://forum.lulzbot.com/u/bam)\ **Post date:** [April 9, 2014, 8:43pm UTC](https://forum.lulzbot.com/t/24v-power-supply-12v-heater/553/2 "2014-04-09T20:43:48Z")
> [@Epicfail](#): > > I had already purchased a similar sized heater, but it requests 12v 20a… as compared to the 24v 10a. Heyo! I wouldn’t run the heater at more than the rated voltage, but this is pretty easy to set in the firmware. Assuming you’re using Marlin, you can set the voltage that’s sent to the bed by changing the line in configuration.h: #define MAX\_BED\_POWER 206 255 = full 24V, so setting this to 127 will send 12V to your TAZ. Keep it up, we always like hearing about home builds 🙂 Cheers -bam ---
**Author:** ![Epicfail](https://avatars.discourse-cdn.com/v4/letter/e/96bed5/32.png) [@Epicfail](https://forum.lulzbot.com/u/Epicfail)\ **Post date:** [April 10, 2014, 4:00am UTC](https://forum.lulzbot.com/t/24v-power-supply-12v-heater/553/3 "2014-04-10T04:00:43Z")
Oh cool! Thanks a lot bam! I would be lost without people like you. So, at that rate, it would be 12v 10a? WOuld i just heat up at half/quarter speed or would it potentialy just never heat to the same ammount? ---
**Author:** ![Orias](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/orias/32/3_2.png) [@Orias](https://forum.lulzbot.com/u/Orias)\ **Post date:** [April 10, 2014, 3:04pm UTC](https://forum.lulzbot.com/t/24v-power-supply-12v-heater/553/4 "2014-04-10T15:04:09Z")
I would think that it would pull as much current as it wanted, even at the lower voltage. ---
**Author:** ![Epicfail](https://avatars.discourse-cdn.com/v4/letter/e/96bed5/32.png) [@Epicfail](https://forum.lulzbot.com/u/Epicfail)\ **Post date:** [April 11, 2014, 1:06am UTC](https://forum.lulzbot.com/t/24v-power-supply-12v-heater/553/5 "2014-04-11T01:06:06Z")
Orias, Im not sure what you mean. I dont know enough yet about electrical engineering and currents , voltage, etc to understand clearly I suppose.