Breville Barista Express - Dimmer mod - Flow Profiling.

[rspierenburg]

I've seen a lot of information about adding a 120v dimmer to the Barista Express to allow for flow control. As a step above that, has anyone thought perhaps of replacing the dimmer with say an Arduino and voltage regulator? This could potentially allow for flow profiling similar to say a "Decent" machine.
For example, you could "record" a manual flow profile, and if that profile yields a favorable result you could "save" the profile as a graph and then in theory "play back" the profile to attempt to yield a similar result.
Personally I'm not technical enough to program the arduino but I can't imagine it would be that hard for someone with a little more knowledge than I.

Just a thought,
Robert

 

[GoatSnaggler]

That sounds like a great idea. I have an arduino education kit. I’m going to look up how to make an adjustable voltage controller!!! This sounds so cool to be able to record it

 

[GoatSnaggler]

I've seen a lot of information about adding a 120v dimmer to the Barista Express to allow for flow control. As a step above that, has anyone thought perhaps of replacing the dimmer with say an Arduino and voltage regulator? This could potentially allow for flow profiling similar to say a "Decent" machine.
For example, you could "record" a manual flow profile, and if that profile yields a favorable result you could "save" the profile as a graph and then in theory "play back" the profile to attempt to yield a similar result.
Personally I'm not technical enough to program the arduino but I can't imagine it would be that hard for someone with a little more knowledge than I.

Just a thought,
Robert

Also. I have done the Dimmer a few times. I don’t have “profiles” but I do make the majority of my shots lower in pressure.

 

[Enigma-2]

I apologize for resurrecting an old, dead, thread, by I just joined and was reading over the old Breville threads; and came across this one.

For reference I have a Breville Barista Express and am a newbie (actually I'm as old as dirt, but .. that's another story.)

Anyway, I feel that using any means to lower the voltage into the Breville is a very bad bad idea.

The electronics internal to the machine rely on a certain minimum, input voltage. Voltages less than the minimum will cause havoc and possible failures. (Some appliances have low voltage protection for thier electronics, but I doubt expresso machines do.)

Besides that, it's my beginner's understanding that espresso needs to be extracted at 9 bar (130 psi) pressure. Using a low voltage at the input would cause the pump to run slower, produce lower pressure (not develope the required 9 bars pressure) and possibly burn out the pump due to producing too much heat. (It's only a guess on my part, but I wouldn't want to find out the hard way that I was correct.)

Before resorting to such extreme measures, I can't help but wonder if there aren't several variables that should be tried first.

1. Perhaps changing the extraction temperature. From what little I've read so far, some beans need a higher (or lower) temperature to extract properly. (I really woukd like to find more information on this, not much out there on bean type vs. temperature.)

2. Slow the extraction speed by decreasing the grind size. (Smaller grains compact tighter making it more difficult for the water to force through, slowing the extraction.)

3. Increase the amount of ground coffee, instead of using 16 oz. of beans, use 16.5 oz. or 17 oz.? (A thicker puck will lengthen extraction time. I haven't done any experiments with this, just thinking out loud.)

Anyway, I respectively disagree with those who poster previously; I feel it's not a good idea to lower the input voltage as these appliances are NOT designed to operate at lower input voltages.