Need help designing a simple(?) electrical circuit

[Naja002]

c) so at very low differential pressures, we are talking about something far less than 16.7mV, possibly a couple mV.

Yes, 1psi range = 1.67mV/V according to the specs.....



Again, this may be wrong--or maybe I am just understaning it wrong:

Pot 1 is simply to bring the DC power supply into the 10-16v range---should it need to be....

Pot 2: the PTD Outputs mV. so a Pot that functions on a mV level could be used with the proper relay to pin-point/adjust when the relay triggers.

That's my understanding---and maybe its wrong.... I'm out of my league to start with...

But I'm always willing to learn.

I think what Scolley is seeking, and that I need also, is:

1) Somebody to do the Research and say: "Buy this, Buy this, Buy this...Hook it Up exactly like this, and then pay the bill when You get it....

Or

2) For someone to step outside of the electronics world and break all this down into simple layman's terms.......

Excitation....? What is that? I've tried to find an understandable definition, but I haven't found one Yet! Does that simply mean: "InPut Power"....? The PTD needs 10-16v of InPut Power as opposed to 6v for my camera, 110v for my lights, 12v for my PC......?

Understanding how electronics actually makes things happen has always been my personal weak-spot. I would love to learn it and understand it, but its just so Latin......

I have a good understanding of Residential Electrical and some Industrial, but things start to blur after that.

Would You happen to know of a Good website for Beginners....?

[Sponsors]

[Naja002]

It looks almost perfect. Wadda ya' think?

It looks Good and would save a lot of the Electronics hassles. But it depnds upon Your ultimate Goal:

Based upon your Approx. interior tank size--47" x 17.5": 1.6" of water equals 5.7 gal. So, it won't work for 1gal. water change x 7/day.

According to this Tank Calculator



But it would possibly work for a 14% (5.36gal) daily water change for ~50%/wk.

And would probably work well for anything larger.

Also, I would guess that you would need to maintain the water level in your tank at least 1.6" below the rim of the tank---to hedge your bet on the margin of error.

[scolley]

Originally Posted by Naja002

But it would possibly work for a 14% (5.36gal) daily water change for ~50%/wk.

I believe my tank holds about 70 gallons of water, including space lost to plants and substrate. But I'm not gonna worry about how much has to come out daily to replace a 50% weekly water change. That is easy to figure out, and easy to work through. I created a simple spreadsheet to help calculate that.

You can find it here if you have excel, and want to check it out. But I DO NOT want to answer a bunch of questions from people on the spreadsheet. It's got everything in it, including the kitchen sink, that I use to manage my tank. And LOTS of it does not work.

Originally Posted by Naja002

Also, I would guess that you would need to maintain the water level in your tank at least 1.6" below the rim of the tank---to hedge your bet on the margin of error.

I was figuring adding 0.5" to that for comfort, giving me a range of around 2.1" on the low side, and 0.5" when it is pumping high.

[scolley]

OK, I went out and bought one of these - the 1 amp version.

So I don't need a circuit designed anymore, and please take this conversation back to the originating thread here. That is unless for the communities sake, you wish to post a "how-to" on my original request for a circuit design to support a pressure sensitive transducer.

I'd like to thank Andrew (g8wayg8r) for his excellent help here. And the same goes to Snafu. Thanks folks! It's just too bad that I don't have the knowledge to follow up on some of your advice, and had to buy something... building it myself would have been way cool!

And I appreciate Naja002's contributions here too. But for more stuff from that poster, please take a look at the aforementioned original thread where we are trying to figure out not a circuit design, but how to replenish a tank without visible equipment. And Naja002 has made a massive contribution to this area, one that may ultimately benefit the whole community.

So if you are interested in such d*mn foolish waste of your perfectly good time, come join us over here.

Thanks again for the help.

[Naja002]

Personally, I am interested in pursuing this--if anybody wants to take me by the hand and walk me through the park.....

If not,.......

[scolley]

Originally Posted by Naja002

Personally, I am interested in pursuing this--if anybody wants to take me by the hand and walk me through the park.....

If not,.......

By all means... keep the thread going! It would be great to get a solution here.