12v pcb heatbed on 24v
-
I have a 12v PCB heatbed. If I fed it 24v directly it would run at about 15-16 amps. From a hardware perspective, would the board be able to sustain this load if I limited the pwm to 66% giving me an average 10A or is the peak current too high? I don't want to get a 24v pcb bed because they often have too high resistance values limiting the power output to measly 100-125w. I should probably invest in a silicone AC heat pad, but I don't seem to find reasonably priced SSR that can be trusted. Had a bad experience with ebay ones…
Thanks for your advice.
-
I don't recommend relying on PWM to reduce the heater power.
What sort of PSU do you have? If it is a CCTV/LED type then you can probably turn up the voltage to around 14V.
-
As an alternative perspective, I run a 300x200 PCB heater though its 12v connectors using a 250W 24v PSU. What happens is the PSU runs maxed out so I fitted a fan to it, but the heater works fine. I am not running it via the controller but via a fused mechanical relay. So no its probably not the ideal arrangement but when I hooked it up initially via its 24v connectors it would only draw 4A from the same PSU and wouldn't get up to ABS temperatures. Maybe consider a thermal fuse also. If you have a much more powerful PSU this might be unwise. So I'd say modest PSU and a relay and its doable.
I have no experience with using PWM to effectively run 12v devices on 24v so if David thinks its a bad idea I'd be inclined to believe him.
-
DjDemonD good to know you can run a 12V heater at 24V. It makes sense. A typical 12V PCB heater is 12v^2 x 1.2 ohms = 173 watts. At 24V, 24v^2 x 1.2 ohms = 691 watts. As long as the copper traces and the PSU can handle it, why not?
I always use a 12V hot end heater on 24V. It heats up wonderfully fast!
-
@haleyp said in 12v pcb heatbed on 24v:
I always use a 12V hot end heater on 24V. It heats up wonderfully fast!
And if the heater mosfet fails short circuit, you will have melted heater block and probably a fire.
-
-
@t3p3tony said in 12v pcb heatbed on 24v:
@dc42 I think @haleyp was referring to a heated bed not a heater block
Possibly, but he did say "hot end heater" in the line that I quoted.