Manual pump control

General
1

I have the 24v PWM controlled pump and I use it for recirculation during mashing and wort transfer during my brew day. It’s hooked up to a fixed 5v control voltage and an on/off switch. I would very much like to be able to control pump speed, preferably using a manually operated knob or similar. Could you please advise on how to achieve this?

I have a spark 3 used for fermentation temp control and I think I understand how to make it control the pump, but I don’t want to use a web UI to switch the pump on and off while mashing. Can I hook up an analog knob to the spark for input?

Some suggestions or pointers would be much appreciated.

2

I’m not aware of any currently supported slider / knob inputs for the Spark.

LED strips commonly come in 24V with dimmers. You could use the 5V as global on/off, and use a 24V knob for physical control.

(Do check electrical compatibility before implementation. This is based on me installing LED strips, not me combining them with pumps.)

3

This is incorrect @Bob_Steers.

The PWM pump has internal speed control, you should not try to regulate it through its 24V power supply. It should get a pwm signal for the speed.

The Spark doesn’t support analogue input. You could give the pump just digital signal for on/off at full speed and perhaps use a valve to pinch off the output a bit.
Or let the spark send a speed control signal that you can interrupt with a switch.

4

I have it nicely wired to my mash/boil controller using a 3-wire XLR plug so it gets the 24v power and a 5v control signal that I can toggle with a small switch. Doing the same thing using the spark wouldn’t make much sense. I guess restricting the flow using a ball valve would be pretty simple. Thanks!

I did actually hook it up to a cheap PWM fan controller I got off some website, but that didn’t work at all.

5

You can have the manual switch and digital speed control.
If the spark sends the speed signal, your switch can override it (interrupt it) to turn the pump off.

I have something similar for my heating elements, they turn on if all of these are true:

  • the spark digital pin is ON
  • a manual switch on the panel is ON (to turn it off regardless of software signal)
  • the float switch is ON (to protect against dry fire)

Wired as follows:
Spark signal + --> manual switch --> float switch --> SSR +
Spark signal - --> SSR -

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