[chbot] Opto isolated triacs

[Mark Atherton]

Can't help but think that NTC inrush surge protection may be helpful, 
and simple to install

Are you 100% sure that the transformer **always** produces less than 24VAC ?

How about sticking your scope across the 24VAC secondary and 
switching on and off the largest relevant load you have at the 
property (well pump, swimming pool heater ??) and see what happens

Have you traced through the secondary of your commercial irrigation 
controller ?

Have you powered up the commercial irrigation controller, and had a 
look at normal solenoid operating voltage ?

-mark

At 04:08 p.m. 9/01/2015, you wrote:

> > I'm only switching a max of 200mA @ 24VAC to operate irrigation solenoid
> > values. My homebrew controller can handle 32 valves (or pump controls) and
> > it all runs fine for the last 3-4 years apart from the occasional solenoid
> > going open circuit for no reason that I can find.
> >
> > I'm looking for minor adjustments rather than wholesale redesign to save
> > money on solenoids!!
> >
>
>I'll bring a couple of solenoids along to the next meeting - perhaps
>someone will have better luck than be determining the failure mode...