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Topic: Need help with Solenoids. (Read 636 times) previous topic - next topic

lost_and_confused

Yes, I know....  "search the web".

The problem where I am stuck is pump, solenoid, pressure and cost.

This is already costing a bucket load of money - kind of - but a recent development has blown the whole thing out of the water, so to speak.

I was going to get a cheap pump with not too much of a flow rate as the pipes are not going to be closed at the ends.  They will simply drain into the plant pots.

Each plant will have its own pipe.  Thus solenoids for each plant.

PROBLEM:
The pressure out of the pump is not enough to close the solenoid.
It seems the solenoids need pressure to close them.

Getting solenoids that don't need pressure cost big $$$$.
Getting a pump which can supply the pressure to make the original solenoids close also costs $$$$ compared to the pump I was going to get.

What other methods are there to "switch" where the water goes?

jackrae

Have you tried reversing the water flow connections on the solenoids.  Solenoids should, if anything, need pressure to open - not pressure to close.

lost_and_confused

Well, at this stage, I don't have any.

I am pricing them and getting the specs.

The ones I am wanting are normally closed, and with 12v DC they open.

So the power opens the valve.

Removing the power - I thought - closes them.

Alas not all.  And the person with whom I was talking say those kind cost.

In the mean time I have "discovered" washingmachine solenoids.  They seem to be what I want, though they don't exactly have an ouput thread.  It is more a spigot.  But that would suffice.  I just use smaller pipe.

I have sent off a request to a supplier, but what I am asking is not the usual questions so I am not holding my breath for a reply.


Ah, the quest continues.

;)


dc42

You can buy washing machine solenoids as spares, e.g. in the UK from http://www.buyspares.co.uk/search.pl?query=solenoid. The snag is that they may be 115v or 230v AC operated and therefore need an SSR to drive them.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

lost_and_confused

I have found some local and are 12v DC.

I am still waiting on the specs for them.

Fingers crossed.


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