Hi all, having done a few modifications it’s now time to look at the heat bed. Mainly the time it takes to heat and its ability to maintain that temperature with the fan running on full.
Using a 24v power supply appears to be a proven method. Not surprising as it more doubles the effective standard wattage. The problem is that I don’t have a 24V power supply, but have some really good 12V ones.
My thoughts are, if I find the centre point of the heating element (pcb track) and attach a wire, I effectively have 2 heaters both half the resistance which can be connected in parallel and fed with 12 Volts.
If current = Voltage / resistance and power = Volts x Amps and my heater measures 5 Ohms.
At 24 Volts: 24 / 5 = 4.8A 24 x 4.8 = 115.2 Watts.
At 12 Volts: 12 / 2.5 = 4.8A 12 x 4.8A = 57.6 Watts
But I have two of these so: 57.6 x 2 = 115.2 Watts & a current of 4.8 x 2 = 9.6A.
The heating effect should be the same, the standard ribbon cable certainly won’t be able to handle the 10 A so will need to be changed. Then come some interesting questions:
Can I just change the printer supply from 15V to 12V or would I need to switch using a relay?
Will the K8200 control board run on 12V?
Would a 12V supply have any implications for the stepper drivers or motors?
Will the pcb tracks, connectors and FETs handle 10A without any modifications?
I look forward to your thoughts.