Simple Pressure Sensor/Switch - South Africa

is Google broken today?

It's always broken.

Having someone do the leg work for you seems to be the way work is done now.

I'll go one step further: OP Google "pressure transducer"

Can't anybody do their own work any more?

this might work

I agree simple flow switch is the best method.

This is a short tube screwed into the line which has a piston and a light spring this will move when the water flows through it, a small magnet mounted in the piston can activate a reed switch on the outside of the tube and switch whatever indicating system on. It could even be rigged to an electro mechanical counter to indicate how many times it has been operated.

The flow switch is so simple you could make it your self.

Dear All

Today I purchased a VW oil pressure switch for under $5 US and will try that out.

Not sure at what (lower) pressure it will close the contacts but I will play with it to test.

Thanks to Oraka for pointing me in that direction and to others with some good ideas.

Regards

Mike

mviljoen, I don't know about a VW oil pressure sender, but many senders are analogue devices so they (with a bit of signal processing) will tell you the pressure in the system. If it is only a simple switch, i.e. if the vehicle has an oil light as distinct from a guage, it may not change state until the pressure is down to 5psi (30kpa) or so and that may be too low for your purposes. Ask your local auto-electrician for the best sender for your project.

Silicon sensors are widely used in washing machines, dishwashers, tire inflation indicators, etc. They are available from electronic parts catalogs for any pressure range you can desire. Price range varies.

An oil pressure sender unit from a car/truck/tractor will do it.

Thank you - excellent idea!

How about a 'simple water pump pressure switch as fitted to almost every domestic water supply I have seen in africa. I have also seen racks of them in almost every little hardware store. They are designed to turn on the pump when the tap is opened.

Hang on, lets reinvent the wheel!

But could of course be used to switch any form of alarm, light or buzzer you want to uise to inform you that a tap has been opened/

(happy now Oraka?)

Not if, as I said, it is a simple switch whose switching pressure was below the level that the system would fall to when a tap was opened. Hence my advice to get an analogue sender.

A pressure switch called a Hobbs switch can be set for almost any pressure drop or increase in multiple pressure ranges. At my last purchase they were made by Honeywell. Duke

As happens far too often, many who replied to this subject did not bother to read the question properly. The guy wants to be informed when someone turns on a tap in his system. That is all he wants.

I think it is crazy for some replies to be given GAs when, in fact, they are off topic.

A minor detail.

A sensor, built for cold / hot / soapy water has to be built with electrocorrosion in mind.

Therefore, the silicon sensors I recommended, and the electromechanicals from a plumbing supplies will last.

A pressure sensor built for oil lines are not built with corrosion in mind. There dissimilar metals are mixed freely.

Other than that, I have no strong opinion on the matter.