Once again, I have purchased the wrong supply. In 4 purchases, they’ve all been sub standard in one way or another.
I want a 12v quality supply that’ll be sized to drive two extruders, a 300x300 heat bed, a smoothieware controller…
And have the fan turn off when not needed. I’ve got lower wattage power supplies that are silent when not in use, and I’ve got higher wattage supplies where the fan runs continuously. I also have a stupid 17 amp supply that won’t be enough to drive anything…but at least it’s passively cooled! (I’m thinking I might run a single extruder and I might be able to run a mains heat-bed…but I don’t HAVE a mains head bed.)
P.s. What the heck do I do with a spare 17 amp power Supply?
What wattage? Still use mains for head bed, or 24v…if I’m switching from 12v, I don’t want to find myself stuck, again, with incompatible components (I’m assuming that my 12v head pads shouldn’t be used in 24v environment.)
+Peter van der Walt is correct. At bigger dimensions at least its better off using 24V. You can use thinner wiring and got theoretically fewer losser (from 230V to 24V and in mosfets. Ssrs and so on)
The 17A (~200w) PSU is actually just enough to run a printer with a PCB bed heater. It won’t have enough grunt to get past about 85c, but PWM on it will help. It’s what the Migbot Prusa i3’s run and whilst, they’re not as accurate temp-wise +/- 0.7-1c shift when heated they work .
I am currently…under employed. I’ll most likely size it for a heat bed and dual extruders plus 20%, but initially run a cold bed and single extruder…might run a buck transformer to give a bed 12v or just not bother with it for now…burning the house down is NOT a risk I want to take.
I’ve also got a huge MIC6 build plate…300x300 is the largest, common size heater pad I could attach to it when honestly, it might be simpler sticking to a PCB and restricting the envelope to that. Again, lots of purchased gear I don’t end up using because the plan changes.
I feel your pain. I’ve shipped so many power supplies and evaluated so many, my head spins and stomach sinks when I hear the letters PSU.
Two reasons Printrbot has continued to pursue the 12V PCB heatbeds:
CE testing.
Cost of (real) CE rated PSUs
There you have it. I don’t have words to relay the pain involved here if I were to raise the voltage in my printers, or try to slide one of those “mains” silicon heaters through on CE testing. It’s making me sick thinking about it.
As a hobbiest, it’s hard to tell which ones are good and which aren’t. I had a leftover ATX supply I opened up and got rid of the octopus of wiring…it doesn’t last long (probably why it was left over)…Bought a non-name PSU that ended up not being the problem…but couldn’t use it in the newer printer (went from Delta to Cartesian), as it wasn’t sized for a heated bed. I’ve been buying MeanWell ever since, they’re just not 24v.
Oddly enough, I have a 6v Motorcycle that suffers from the same issues…I really need to convert it to 12v.
I’m using a 12v power supply meant for servers. Apparently very popular with RC hobbyists, they cost around $70-120. The one I have outputs a 12v 2.1a always on (perfect for raspberry pi) and a 12v 38a output (can be switched electronically).
The best part is that it’s really small, and the fan is thermally throttled, most of the time it’s not even on.
The one I have is a delta electronics 460 watt.
You need to find the enable pin, typically it’s the one with the short trace, all you need to do is ground it to turn the supply on. The wide strips are the output, one side gnd, the other 12v. I drilled those and soldered screw terminal blocks.
You can also use the 0.1in, 2 row terminal headers. they fit right on, then you can use ribbon cables.
You can connect the enable pin to a pi or something to turn the supply on and off.
