Multizone heater bed

[Anon1337]

Is there an easy-ish way to run a heater bed with multiple heating elements and then just turn on whatever part of the bed is needed?

Like what the Prusa XL does?

Would be neat for big printers.

[Anon1337]

I mean this was made by you (Duet3D).

Any documentation to go with it?
How were the 3HC board connected to the beds? I mean each 3HC only has 3 high amps outputs but that bad has 9 segments?

[dc42]

@Anon1337 I believe the bed heaters were all AC mains voltage, so controlled by SSRs.

[Anon1337]

@dc42 So AC SSRs connected to the 3HC PWM outputs? How were the segments controlled? Was it automatic or do you have to manually choose what segments to heat?