FrankRPI
Posts: 2
Joined: Sat May 25, 2019 11:19 am

Powering pump

Sat May 25, 2019 3:30 pm

Hi, I am trying to power a small pump using my raspberry pi 2b. If i connect it directly to the 3.3v output it works. However, when i connect it with an gpio output it doesn't... I am guessing the pump requires too much current from the gpio pin? Is there a sollution where i can still use a gpio to control the pump? I have looked for relays, but cant find any that not designed for higher voltages like 230V. Any ideas?

EZKernel
Posts: 19
Joined: Sat May 25, 2019 4:39 pm

Re: Powering pump

Sun May 26, 2019 2:05 am

clicky but cheap:

https://www.amazon.ca/ELEGOO-Channel-Op ... r=8-3&th=1

silent but expensive:

https://www.amazon.ca/Lerway-Solid-Stat ... way&sr=8-5

for the clicky one:

if your pump runs off of the 3.3v it has some king of internal relay that needs that voltage to trigger, in which case you can just use that 3.3v from the pi into the relay (relay is powered by 5v rail), then use the pi to turn the relay on/off and the will be closing the power connection to the pump.

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Imperf3kt
Posts: 2647
Joined: Tue Jun 20, 2017 12:16 am
Location: Australia

Re: Powering pump

Sun May 26, 2019 8:10 am

FrankRPI wrote:
Sat May 25, 2019 3:30 pm
Hi, I am trying to power a small pump using my raspberry pi 2b. If i connect it directly to the 3.3v output it works. However, when i connect it with an gpio output it doesn't... I am guessing the pump requires too much current from the gpio pin?
What kind of pump is it? Is it a water pump for liquid cooling or something? Generally these are impellers and don't require a huge amount of current to move the liquid because there's not much pressure.
Or is it like a small tap pump out of a caravan or something? This will require a large current (~1.5A @ 12v) and certainly should not be powered via the Pi.
55:55:44:44:4C
52:4C:52:42:41

LTolledo
Posts: 1768
Joined: Sat Mar 17, 2018 7:29 am
Location: Anime Heartland

Re: Powering pump

Sun May 26, 2019 8:56 am

what is the nameplate rating of the pump?

The usual suggested connection pattern is:

[RPi]---[transistor switch]---[relay board] ---[pump]

and usually for this kind projects utilizing AC mains.... a stern warning is given to would be enthusiast.....
so if you are not a licensed electrical technician/professional (or not supervised by one) then its best to consult them first...

otherwise there can be serious consequences to you, your family, or your neighborhood.....
"Don't come to me with 'issues' for I don't know how to deal with those
Come to me with 'problems' and I'll help you find solutions"

Some people be like:
"Help me! Am drowning! But dont you dare touch me nor come near me!"

FrankRPI
Posts: 2
Joined: Sat May 25, 2019 11:19 am

Re: Powering pump

Sun May 26, 2019 9:13 am

This is the pump:

https://m.banggood.com/Mini-Submersible ... mds=search.

I want to use it to water a plant.

pcmanbob
Posts: 6646
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Powering pump

Sun May 26, 2019 10:07 am

You will not be able to run that pump directly off a gpio pin , it will draw more than the 16mA a gpio pin can supply.

Nor would I run it from the 3.3v supply on the pi as a motor will produce voltage spikes when switched off that could easily damage the 3.3v supply on your pi.

I would recommend you use a separate 3v power supply for the pump and then use a transistor to switch the pump on & off.

like this

Image

now the transistor /resistor selection will depend on the current draw by your pump, but as your link to the supplier does not list a current draw you will have to measure it your self and then select a suitable transistor.
We want information… information… information........................no information no help
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PhatFil
Posts: 1342
Joined: Thu Apr 13, 2017 3:55 pm
Location: Oxford UK

Re: Powering pump

Sun May 26, 2019 12:10 pm

EZKernel wrote:
Sun May 26, 2019 2:05 am
clicky but cheap:

https://www.amazon.ca/ELEGOO-Channel-Op ... r=8-3&th=1

silent but expensive:

https://www.amazon.ca/Lerway-Solid-Stat ... way&sr=8-5

for the clicky one:

if your pump runs off of the 3.3v it has some king of internal relay that needs that voltage to trigger, in which case you can just use that 3.3v from the pi into the relay (relay is powered by 5v rail), then use the pi to turn the relay on/off and the will be closing the power connection to the pump.
Afaik Unlike mechanical relay options you need to use current specific SSRS for AC and DC loads, an AC SSR will not work for a DC load and visa versa.

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