PSU for Prusa i3

[zx81]

its quite common to use a computer power supply my first I3 used one. 400W should be the minimum .. you should also use load resistors to increase and stabilize the maximum output of the power supply also allegedly some PSU's will shut down if there is a high load on the 12v rail's and no load on the 5v rails.

[ZorAxe]

its quite common to use a computer power supply my first I3 used one. 400W should be the minimum .. you should also use load resistors to increase and stabilize the maximum output of the power supply also allegedly some PSU's will shut down if there is a high load on the 12v rail's and no load on the 5v rails.

What do you mean by load resistors?

[printbus]

What do you mean by load resistors?

As a result of the switching power supply design, some ATX power supplies require a load of some sort to be connected to the +5V output in order for the other outputs (like 12V) to work properly. Rather than go into details, I'll repeat Roxy's suggestion to search on the terms "prusa i3 and ATX power supply", or "rep rap printer and ATX power supply", etc. It doesn't take long to find people who discussed problems with using an ATX power supply and how adding a power resistor to the 5v output got them working.