Why do servo need another 5V?

fra87

Hello

I was trying to enable the servo support when I saw that on the online configurator you wrote

"Please note that servos should have their own 5V source"

Why? Is it just a problem with currents (usually servos draw too much current and so the regulator "suffers") or there is another reason?

Regards

Repetier

No, current is the reason. The 5V you normally have on board is for 500mA which is normally not enough and you get also some feedback from servo so it gets unstable which could cause other problems.

sonnylowe

Hello,

I want to use a BLtouch which draws much less current than a servo, will it be okay connect to the board? If not, what is the best to provide the 5V for the servo?

Thanks,

Sonny

Repetier

Don't know BLtouch but I think a servo should not draw then 50mA if connected directly to board.

Most boards have a pin for supplying servo power, so just add a big enough 5-6V power source there. Could also be from 12->6V conversion from normal power. Problem is usb only delivers 500mA and on board 12->5V converter is not better. So nearly everything goes to LCD and board and it should still be stable for temperature measurement.

sonnylowe

The BLtouch does not use a traditional servo, it uses a very small metal pen and magnetic field to retract the pen (when not in use). I'll check the amperage draw and go from there. If need be, I'll look at the ramp architecture to determine the pin location to add the 5V external power.

Thanks for the quick response and the on going GREAT service!!!

Sonny