Tripping the light fantastic

“It makes a difference, doesn't it, whether we fence ourselves in, or whether we are fenced out by the barriers of others?”

E.M. Forster

As part of the ongoing foray into electrical engineering, with a view to for instance fully automate the hothouse (forgive the intermittent readings - much experimentation is taking place at the moment), we are exploring the wonders of optocouplers.

So as not to fry any control circuitry, these little devices (in our case the 2501) are able to send signals purely by light, creating a protective barrier in the circuit. Why it's like the 24th Century has arrived already!

A bridge of light

The whole shebang means that a possible fry-up on the load side (simulated by the green LED in the picture) would not affect the control side (provided by a 555 timer and indicated by the red LED). Thus all manner of pumps, servos and other inductive loads can happily short out and the micro-controller circuit should live on (famous last words, no?).

Warp speed, Captain!

We get quite a kick out of this stuff (especially when it works), but huge thanks to the interwebs for your advice and tutorials, especially:

• Great Scott
• Julian Illett
• Afrotechmods
• Ben Eater
• Big Clive
• EEVblog

Great contributions to the community, and specifically to us. Thanks y'all. And after having a little fun with the sound effects (don't believe everything you hear), this is the result...