0

Buckaroo Pump/Solenoid Options
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Buckaroo Pump/Solenoid Options

by mnopneal on Tue Apr 13, 2021 7:18 pm

So, the 3v pump offered with the Buckaroo board is of modest means. Adafruit was clear on that. Modest meaning it is unable to lift water more than 5".

This makes it a challenge for using with a garden bed. If the water supply is big enough to last for a couple of weeks, at some point it's going to be 12" lower or more. And the pump can't lift it. If the water supply is higher, the first time the pump runs it's going to start a syphon and empty the supply.

So, for gardening use we need either a stronger pump, or a solenoid valve to allow the supply water to be higher. Any thoughts on options? How much current the board can supply? One would think the solenoid approach might be less stressful. I guess the board could drive a relay, which starts to get more and more complex. It would be nice to be able to keep everything low voltage so this could be run with batteries and small solar panels.

regards,

Neal

mnopneal
 
Posts: 13
Joined: Tue Apr 13, 2021 11:53 am

Re: Buckaroo Pump/Solenoid Options

by adafruit_support_bill on Wed Apr 14, 2021 7:01 am

The on-board MOSFET is capable of 200mA continuous. That is not going to be enough to drive a solenoid valve or larger pump. You will probably need to work a relay or a higher power transistor into your circuit.

These power MOSFETs can efficiently switch plenty of DC current: https://www.adafruit.com/product/355

And we have a few relay options here. The latching type are more energy efficient for long activation cycles. https://www.adafruit.com/?q=relay&sort=BestMatch

adafruit_support_bill
 
Posts: 82093
Joined: Sat Feb 07, 2009 10:11 am

Re: Buckaroo Pump/Solenoid Options

by mnopneal on Wed Apr 14, 2021 10:14 am

Thank you for the reply.

On closer examination, just playing around with the pump plugged straight into the battery, it will eventually lift 9". That's using 3 feet of tubing 4mm ID.

It just takes it at least 7 seconds to fill that tubing, and as soon as the power is off, the water flows backwards to empty the tube.

So in the interest of simplicity, we will work with adjusting parameters for a longer pump cycle time, and look for a one-way check valve.

regards,

Neal

mnopneal
 
Posts: 13
Joined: Tue Apr 13, 2021 11:53 am

Please be positive and constructive with your questions and comments.