I saw this post on Reddit and it made me think "I could do that with my CAD!", then I realized I can't because Psi doesn't have a trick for redstone. It would be nice if there was such a trick, which takes a position and duration, and optional strength.

Pulsar tricks do exactly what you want, here. - PSIonic Upgrades dev

Okay, thanks for clarifying!

Psionic Upgrades has exactly this.

From the mod description, it looks like it can summon a block of Redstone equivalent, but can it activate an existing Redstone device? Like in the video?

There are the Block and the Light variants of the Pulsar spell, they look like this conjured: http://i.imgur.com/Bk1Z2Tb.png
The remote does the same thing the Light Pulsar does, and you can even define time.