Hi
I have an electrical problem with my PSU in connection with a "Power Failsafe Unit".
The Printer is a modified "original prusa i3 MK3/s" with a replaced mainboard to
BTT SKR v1.4 turbo.
The PSU is still the original. Here is the
link to the exact PSU and the Link to the
Bigtreetech UPS 24V v1.0.
Now to the description of the problem
If I hookup everything then the PSU turns immediately off and a few seconds later on again. This in a endless loop. When the Power Failsafe Unit is disconnected, then everything works fine.
I assume that the PSU have a short circuit protection feature which possibly is a little bit to sensitive and the UPS with empty capacitors acts like a short circuit for the PSU.
Therefore I've made a test. I added a 10Ω resistor in the plus line. Then the printer started fine and the Power Failsafe Unit loaded the capacitors as well.
The resistor I used for my test was a rated for 1/4W (assumed). Therefore I took two of them to split the current and give the resistors some relieve. However in short time both resistors begun to burn out.
I don't have Resistors for this amount of current and also think a setup with a Resistor in line is not the best solution.
Glad to have some help in this case. If anyone either knows how to modify the prusa PSU or a knows a better solution, that would be much appreciated.
Best regards
Simon
Printer:
Modified "original prusa i3 MK3/s"
- Replaced Mainboard to BTT SKR v1.4 turbo
- Replaced Display to BTT TFT50
Firmware:
- Marlin-bugfix-2.0.x
