>
>That said, I am aware of the issues of 110VAC in a tub, which I why
>I wanted to use just a few DC volts.  I'm not aware of the leakage etc
>with relays.
>
>Are you suggesting that there's potential danger with 4.5V DC in a
>tub?  Or are you saying that the 110VAC from one of the relays
>could leak to the 4.5V side of the circuit?

   No, it's not a problem. Unless a relay could get accidentally
   splashed with water...

>No existing temp sensor -- just switch on both valves and dump
>hot and cold water for a specific time.  Variances in water pressure,
>and hot and cold temp make that incredibly inconsistent. Sometimes
>it works out, and sometimes I need to add hot water to get the temp
>right.

   Non-contact is the way to go. Buy a threaded stainless
   through-wall probe from Omega. Rolling your own is risky.
   My experience is that the liquid will eventually work
   its way through most home-brewed seals.

   Reg

   p.s.: I'm seeing this entire thread repeated. Anyone else
         getting the same thing?

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