help with pump control

If the valve on the water tank end is good enough, a simple pressure switch on the air pressure tank would serve the purpose of controlling the motor. It could be designed top stop the pump at, lets say 150PSI and restart it at 100PSI. The backlash and the size of the air tank would prevent short cyles on the pump.

pressure sensor next to the pump, float valve at the tank

O pressure sensor check | pump valve | --(S)--->>----+---------------------------------|o float valve | \\ | O |~~~~~~~

When the tank fills the float valve shuts off and the pressure in the pipe rises, this activates the sensor which shuts off the pump, the check valve stops the water pressure from leaking back through the pump.

Bye. Jasen

People have pointed out a much easier system using normal valves and plumbing parts. I'll watch this thread. If that doesn't pan out I'll fill things in a bit.

On May 7, 6:43 pm, snipped-for-privacy@cwnet.com wrote: [....]

Assuming you really want to do this, I'd look to using:

This part works in the visible range so you will be able to see when you get things aligned. I'd use an superbright LED not a Laser because the laser would be very hard to aim. If you use a LED, there will be a smaller signal at the receiver but easier mechanicals.

The signal you get from this is very tiny. You need to amplifiy it a lot to get up to the relay driving level. We need to not be confused by the sun etc. This is done by pulsing the Laser and looking for the pulses at the receiver. This can also save you some power.

At the transmitter, I would suggest a CD4060 or HC4060 as the basic oscillator to set the frequency of the laser or LEDs blinking. The CD4060's datasheet shows how to make an oscillator from it. The CD part is slow but will work over a wide range of supply voltages. It has many divided outputs that will let you get some frequency around

The output of the CD4060 needs a transistor to boost its output to drive the Laser or LED. 2N7000, TN0604N3 and many others will work here. Don't forget the resistor in series with the Laser of LED to set the current.

At the receiver, the easiest way to amplify the signal is to use an op- amp circuit. Doing it with an op-amp takes a lot less parts.

The receiver circuit is mostly a band pass filter tuned to the frequency of the laser's blinks and a detector to detect the AC on the output of the filter and drive the relay circuit.

ry hard to aim. =A0

Another really good reason to avoid laser diodes is their susceptibility to static discharge. (Think lightning damage here.)

That said, Banner Engineering is another good source of laser diodes, lenses, parts, etc..

-mpm

I'm afraid 'mpm' thinks this is too simple. It's a method I used for twenty years in my previous property. The system fed six houses and we never had any problems. It was pumping around 1000 gallons per day over a static head of 110psi and a linear distance of 1 1/4 miles.

fun

oss

=A0 =A0 =A0 =A0 =A0 =A0 =A0| \\

=A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0O

=A0 =A0 =A0 =A0 =A0 =A0 =A0|~~~~~~~

Huh???

I think you have me confused with someone else. I only posted the Banner stuff because folks were still talking about laser diodes (people who have obviously never engineered them for outdoor use, I might add.)

Use a pressure switch/sensor. Much better approach. (See my original post).

As for those 8 or so elbows in the pipe ... Maybe this is one of those rare occasions when it's acceptable to place a gerbil into service. Smoke on one end, small string attached to hind legs... you get the idea.

-mpm

Nevermind. I see now that you simply mis-read the post. I probably could have trimmed MooseFET's prior post a little better.

. . .

. . .

Sorry, yes I did.