Needing to send a one shot pulse to a 12v solenoid valve via a DPDT switch that activates constant 12v power as well as sending this constant to 555 circuit. This needs to happen on a normal polarity & also reverse polarity circuit. New to this kind of thing, so if someone has a solution as a diagram it would be much appreciated. Thank you in advance.
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Hi Tris
Welcome.
Well, that is going to be one very confused solenoid.
A few questions.
What are the unmarked boxes. Could we assume they are 555s.
Do you want the water pump to run in both switch positions or only run when the solenoid valve is open.
At the moment you have both NO (Normally Open) sides of each switch connected together so everything is going to get the same voltage applied irrespective of switch “ON” direction.
If you can lay out exactly what you want to happen and at what time we might stand a chance of helping.
Cheers Bob
Thanks Bob. I’ll probably confuse things by trying to draw it.
Basically I need a pump turned on via a toggle switch (not momentary) with either solenoid open or solenoid closed (it’s latched so this is achieved by 2 states normal & rev polarity)
So I need the switch to do 2 things.
- Turn the pump on
- Select polarity setting via 2 different switch states
This all to happen via a ON/OFF/ON switch.
I hope this helps
Hi Tris
Let me think about it.
Could you tell me what is the resistance of the solenoid coil or better still make and model as well
If required are you OK with a couple of 555s or a 556 (dual 555)?
Cheers Bob
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Hi Bob,
I believe the resistance of the The HR MV75 12v is around 4.8 ohms. It’s a micro solenoid valve, commonly used in micro-drip or micro-spray home watering systems.
2 x 555s or a dual 556 would be fine.
Appreciate you looking into this
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Hi Tris
Well I had a look for some kind of data sheet or more detailed information.
Nine tenths of bugger all on HR web site or anywhere else for that matter.
Does not help that all types seem to have the same model number.
Might be commonly used but if contemplating using this brand I think you would be flying a bit blind.
I can find plenty for sale but almost no info.
Cheers Bob
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I can find out more details. In the meantime happy to hit it with 30ms of 12v dc straight from battery. I can test a few resistors to check threshold maybe? so not too concerned about that side of things. Overall circuit is my bigger issue
