I am installing a pair of skylights and considering if I could automate them with a Raspberry pi. The same could apply to windows or blinds, so I am hoping someone has done similar.

Is this a safe and effective way to use two automated relay switches to control a two directional actuator used to open and close a skylight?

manual and automated switching

The idea is to never allow both Open and Close circuits to be live at the same time. This is the way I thought that could be achieved but have little to no experience.

This follows on from: Can this double-pole double-throw switch be simplified for controlling a motor (skylight)

  • \$\begingroup\$ Obviously it wouldn't happen by design, but if the pi activated both relays in error you would activate both motor coils. \$\endgroup\$ – Finbarr Nov 21 '17 at 10:40

Just continue the same scheme as the wall plate switches using SPDT relays.


simulate this circuit – Schematic created using CircuitLab

  • \$\begingroup\$ Ok, that's a better answer than mine now! \$\endgroup\$ – Finbarr Nov 21 '17 at 11:40
  • \$\begingroup\$ And you make it look so easy! 240V solid state SPDT relays seem easy to source, next step do not electrocute oneself \$\endgroup\$ – KCD Nov 21 '17 at 18:37
  • \$\begingroup\$ Stand on a rubber mat and keep one hand behind your back :). \$\endgroup\$ – RoyC Nov 21 '17 at 20:13

Here's one way to do it:

enter image description here

One relay switches the system between automated mode and manual mode, the other determines which direction it goes in automated mode. Set the direction first, then activate the automation relay for as long as needed for the motors to work.

There's no way of activating both motors at the same time.


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