Td5 pump without pwm

Is it possible to use the td5 pump, the one without the blue wire, with a seperate PWM controller in combination with brewblox?

I’m asking this because I can’t get my hands on the TD5 with the blue wire…Maybe somebody knows where to buy this pump?

So I bought the non speed control pump with the thought that they’re probably the same pump but without the blue wire. I used a heat gun to expand the poly housing and gently tapped the guts out to see. It appears I was right as there are provisions for a tach wire and speed control wire (much like a 4-wire PC fan). I just don’t know how to control the speed once I add the blue wire. Also, it appears there are unused pads on the circuit board. Not sure if those are for 0-5V or tach use.

As it seems this is the only version of the TD5 in the US, it would be nice if it could be upgraded to PWM control.

@Elco, Thoughts?

The pump on the brewpi store says:

The pump blue wire of the pump takes a 5V or 3.3V digital signal to control the pump. On/Off or PWM are supported.

Control signal: up to 5.5V, 100-1000Hz for PWM.

The speed control board in the brewpi store says:

Our custom TD5 pump has an internal speed control circuit, which is controlled with a 0-5V analog input signal on the blue wire.

I noticed that the label on the pump in the picture says blue wire is good for 0-5V.
Perhaps either 0-5V or PWM work?
Perhaps the empty pad is for that feature?
Makes sense to use the same board for both versions.

Connect 2V to Vsp and see what happens.
Thanks for your sacrifice.

What is the model number on your pump?

I would have to ask the manufacturer whether they add something or not.
But I would indeed just try it. If there is an RC filter on the board, PWM might work, otherwise you could add one externally. But judging from the photo, that would be on the other side of the board.

The model number is TD5-A24-2505-P/US. I’ll get the wire soldered on and the pump reassembled then I’ll try various signals.

@elco, the manufacturer is not happy that I disassembled a pump… There will be no help from them. What does your pump do if the blue wire is not connected?

I took pics of the concealed side of the board as best I could. Not sure they’ll be much help but here they are. I also followed the trace from the VSP wire connection to an IC on the circuit board, so it should do something.

No clue based on schematic. Could very well be that the microcontroller is programmed differently for different versions.

What happens if the blue wire is not hooked up to anything on the 0-5v pump?

It does not run. So I think your pump will have a pull-up resistor somewhere. That would be much simpler for them than changing the software.

Thanks! I’ll look for that. I also got a second hand 3-wire Topsflo pump (though not a brew pump) on the way. I’ll pull it apart to compare.

@walkinghispath Did you ever open up the PWM version? Figure out if its the firmware or the hardware?

I did, but the PWM pump I have isn’t the brewing pump and is completely sealed in opaque epoxy, so there’s no way to now how it works. If someone wants to pull apart a voltage controlled version of the brew pump I’s be able to tell what’s different, if anything.

I suspect it just has a pull-up resistor and removing that, plus wiring in a voltage control wire would do it, but I can’t be certain without seeing the voltage controlled one.

Alternately, they now sell a directly PWM controlled pump, which is much simpler to use with a microcontroller.

Any news on this?
I’d also love to find a way to wire in the pwm support.