MOSFET Mania

Yesterday finally I installed the finished board into my 3D Printer. It works correctly with some minimal heatsink added.

The next will be the test of the current monitoring.

I just replaced the IRFZ44 MOSFET to an IRLZ44. Now it works perfectly. It switch on around 2.1V

Hopefully I can test it in the 3D Printer tomorrow morning

Today I switched on and started to measure the circuit.

It switches on correctly and working except one thing. My original feeling unfortunately had been verified. The switch on voltage of the MOSFET I used (this one I found at home) is to high.

It switches on at 4.5-4.7V what is not really acceptable for the output of the Arduino inside the 3D Printer.

So I need to change the MOSFET to something else before I can continue.

I checked the datasheet of this one. It states that the Vgs threshold voltage should be in between 2 and 4 volts. :-(

But, I've the replacement type: IRLZ44N. This is definitely a logic compatible one. Hopefully during today I'll be able to pickup some.

The first board (this for my 3D Printer) has been finished. It is ready for testing some cleanup would be useful :-) There will be some measurement (FET Rgson, current measurement calibration, etc.)

Seeing this project I'm thinking about two derivatives: an enhanced RAMPS board, and a Brushed DC rpm controlled driver for my CNC.

The Schematics and the PCB design is finished. The current version is suitable for the 3D Printer. The CNC spindle driving will need some more work because the massively inductive behaviour

I started working on this project. The first version of the schematics is published on the github.

I've a little problem with the current sensing amplifier and therefore some modifications are still come: I want to make it a little bit more versatile therefore I plan to add INA193-INA195 also as an option. This ones are not able to work from 48V supply so in addition I'll add a zener based regulator as an option.