A419 binary input function

[MeBrew2]

I've been using my A419 for several months now. I've used both the heating and cooling functions.

I'm wondering if anyone who uses this has found any use for the optional binary input switch and the offset function. I don't understand these options if someone can please explain.

Thanks,
cris

 

[day_trippr]

The OFS function (along with an SPST switch you provide and wire between the BIN and COM pins) provides a convenient way to have secondary setpoints for cooling and heating modes without having to reprogram the A419.

The example shown on page 4 of the user manual shows "normal mode" setpoints for cooling and heating modes, along with how those setpoints are altered by the value stored in OFS when the SPST switch is closed. If you notice in the example, the OFS mode raises the cooling setpoint, and lowers the heating setpoint, by the same value.

That would be eminently useful for a semi-automatic home thermostat for energy conservation, as it would provide a "set back" mode. Using the same example, if you flipped to the OFS function on the way out the door, the HVAC system wouldn't heat as high or cool as low. Good stuff for that.

But I haven't come up with a "really neat" use for that feature in brewing. Maybe someone else can think up something. If the OFS mode were to shift the setpoint instead of "spreading" it, that might be useful for transitioning from primary fermentation to post-fermentation clean-up temperatures (eg: go from something like 64°F to 68°F to help the yeast clean up after themselves); or, alternatively, switch from fermentation temperature down to cold-crash temperature. But the way it works neither can be facilitated via the OFS function...

hth

Cheers!

 

[MeBrew2]

It does help. Most of my temp changes are around 8 degrees. I could try it out for that although i usually step down the temp slowly.

Maybe I could set it for one or two degrees and when I'm ready to lower temp I lower set point two degrees, flip the switch on one day later. A day after that Lower the set point 4 degrees (and flip the switch off to exit secondary mode) flip the switch on one day later and program only half as many times to drop 8 to 10 degrees.

So literally all I need is two wires and a spst switch right?

 

[day_trippr]

If you happened to live in a climate where the ambient temperature around your fermentation chamber/fridge/keezer was below the temperature that you wanted to "step down", the fact that the heat mode setpoint would drop by whatever value you put in the OFS setting would be somewhat helpful, as you could just let the chamber drop on its own.

The problem, otherwise, is enabling OFS doesn't move the setpoint for the cooling mode down - it moves it up. So, let's say you live in Acapulco, it's summer, you're fermenting in a fridge at 64°F, and then you want to drop the temperature. Enabling OFS with any value greater than zero would cause the cooling mode to not kick in at any temperature below 64°F - it would kick in at 64°F+differential+OFS. You'd actually be raising the temperature of your beer by the OFS value, not lowering it.

But, yes, all you need is an SPST switch and two pieces of wire to control the OFS function...

Cheers!

 

[MeBrew2]

I see I should have caught that when I was processing ur 'this would be useful when leaving your house and controlling ac and heater to turn on less' comment.

I would have to use it in reverse then.
It's 70 degrees outside.
My ferment is 63*.
1. Set the set point 4 degrees below current temp (59) and Set the offset to 2 degrees and turn on.
2. Once it reaches offset temp (61*) or 24 hours (whichever is LATER) switch it off and it will then drop 2 more degrees to set point (59*).
3. After another 24 hours Drop set point 4 more to 55* and switch spst on so it will cool to 57*
4. A day later turn off spst and it cools to 55...

Sound right?

 

[MeBrew2]

Seems hardly worth it since programming is easy. But wait till they see how cool the bitchin switch looks!!! Lol.

Men, toys.