How many valves can I power?

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borsfish
 
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Joined: Sun Sep 15, 2013 10:14 pm

How many valves can I power?

Post by borsfish »

I am building out an automatic aquarium water changing system. I want to use:
- Brass Liquid Solenoid Valvehttp://www.adafruit.com/products/996
- 12V 5A Switching Power Supplyhttp://www.adafruit.com/products/352

A float switch will be used to open the valve when the water level drops.

Excuse the lack of technical knowledge . . . I'm an aquarium guy, not a electronics guy.

Here's where I need some help:
1) I will need to power eight valves total. Can I power multiple valves with a single power supply. How many do I need?
2) I would like be able to quickly disconnect power to the valve. What connectors would you recommend?
3) I'd like to know when the valve is operating, perhaps with an LED. What will I need to do that?

Thanks in advance!

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adafruit_support_bill
 
Posts: 88096
Joined: Sat Feb 07, 2009 10:11 am

Re: How many valves can I power?

Post by adafruit_support_bill »

1) It takes 12v@3A to open the valve. But once open, it only takes a fraction of that to hold it. If you use PWM to reduce the current after the valve opens, a 12v 5A supply like this can probably handle 4 or more - if you don't try to open them all at the same time.
2) Electricity and water don't mix well. To play it safe, I'd suggest waterproof connectors. We have a few types: http://www.adafruit.com/products/743
3) Just an led and a current limiting resistor connected in parallel with the valve will do it.

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