> The type that say 3-32VDC in can generally be driven
> directly from a PIC. I've never seen one that is not
> galvanically isolated, though very old ones used reed
> relays or magnetics rather than optos.
>
3-32vdc things are coming!  OK, so we need to limit the current
for this thing as though it were an LED  20 mA
(I understand this problem but just barely)


>
> You need a LOT of heat sinking for high amp switching.
> As a first approximation, think of 1W per A. A 50A element
> will require a BIG heatsink. Keep in mind that semiconductors
> typically fail ON and try to avoid getting killed in ensuing explosions
> etc.
>
I think the element is around 10 amps(110vac), and I ordered a device
that claims to handle 230VAC and 40 Amps.

I going to try this and stand back the appropriate distance.
There's plenty of room to put a big heat sink in if required.

Now you are saying that this device, a solid state relay, will get
very hot?  It will not be switching on and off quickly.  It is a
water distiller that will pretty much be on then off.  I plan to
somehow monitor the water level in the boiler and fill this up
when required.  And then switch the entire thing off when to
product tank is full.


Thanks to All, Happy Holidays Too.










> Best regards,
>
> Spehro Pefhany --"it's the network..."            "The Journey is the
reward"
> speff@interlog.com             Info for manufacturers:
http://www.trexon.com
> Embedded software/hardware/analog  Info for designers:
http://www.speff.com
>
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