Aquarium Water Change Project

[strantor]

Guys, guys...
Come on now...

I'm super busy right now (moving to a new house)
No time to provide useful input, but later on this evening I'll sit down and go over post #24 and get back to you.

[wayneh]

Originally Posted by blindtrevor

I'm using a Seneye. I've been talking to the dev's and they're hoping to make some sort of API so I can tap into the raw data from it... but it means I don't have to build my own circuit for it - why bother when someone's done the leg work already!

http://www.seneye.com/

Hmmm, that device appears to only monitor (input) a few parameters and has no outputs that you could use to control relays and such. I thought maybe you were using something more versatile, like the other devices I noted. The Seneye probably wouldn't help much with your flushing project. Those other devices can control all sorts of outputs from your computer, programmed as you like.

[blindtrevor]

Originally Posted by wayneh

Hmmm, that device appears to only monitor (input) a few parameters and has no outputs that you could use to control relays and such. I thought maybe you were using something more versatile, like the other devices I noted. The Seneye probably wouldn't help much with your flushing project. Those other devices can control all sorts of outputs from your computer, programmed as you like.

Yeh - it basically monitors my tank for me... and if there are problems it emails and sends me a text... What I was discussing with the developers was for them to ALSO send some sort of API command that I can use to fire off a water change.

I haven't got the time or patience to be inventing my own tank ph and amonia monitor - I'll leave that up to them! But you are right, with more time - it would be nicer to have it all coming from one handy USB device.

@strantor: Sorry - some things just spiral... it's over now! Anyway - I've attached the latest version of this project. I've added a bunch of indicators which will display what's going on... don't worry too much about them! I have also added 2 more switches - one is to start a cycle manually without needing the PC (SW4) and the other is to manually override the lights or auxilary device (SW5).

Hope it all makes sense

[GetDeviceInfo]

Originally Posted by blindtrevor

Then it wouldn't be automatic. The end goal is to have the outlet going into a drain and the inlet coming from some sort of hidden sump that fills itself with water and aquasafe chemicals... but that's another part of this project!

Also - I didn't mention that there will be a solenoid valve on the outlet that will be connected to the same power source as the outlet pump. That way, once the outlet pump turns on - the valve will open, when power is removed - the valve will shut preventing accidental syphoning.

@strantor - I'm not 100% sure on the ladder logic! (at least I'm honest!)

Can you draw it in a standard schematic circuit diagram at all? Many thanks everyone

after years of splashing around in aquaria, I settled on siphon draw filtration. I bore a port into the side of the filter canisters to allow high flow to run off to drain (sourced from below filter media to prevent fry going down and rising media that could obstruct the port). My original conditioning tank was level and continously siphoned to main tank as fresh was added. I did not attempt to adjust chemicals, only to let it 'age'. A line from main filter returned some flow back to the conditioning tank. My last setup had the conditioning tank flowing into a live breader tank (guppies), then into the angel rearing tank. No pumps, no hassle, just a good air stone in the conditioning tank.

No reason you couldn't adjust chemicals in the conditioning tank, other than overdose.

My twenty some odd tanks are stacked in one corner of the basement and the wife is pressuring me to start getting rid of them, but I'm thinking a couple more brood of angels would be exciting.

[strantor]

@blindtrevor - you really can't put things in series man, especially lamps. Lamps are high value current limiting resistors. Your motors are probably supposed to be drawing several amps; you put a lamp in series with it, and now it's only going to get a few milliamps. Putting a lamp in series with a relay coil is going to cause the coils strength to be weak, which is going to cause your contacts to flop around all over, arcing, & burning of the contacts. Other than that, it looks like it should work.

P.S. I highly recommend you familiarize yourself with relay ladder logic diagrams. They really are the simplest, most intuitive way to draw a relay circuit. Your first drawing took me probably 10 minutes to examine; this latest one took only 5 because I was already familiar with most of it. If it had been in ladder form, I could have cut the time down to a few seconds. Actually, this thread is one of 3 in recent memory that has prompted me to make a little "Relay Ladder Logic Diagrams for Dummies" thread. But you can check out AAC's e-book on it for now: http://www.allaboutcircuits.com/vol_4/chpt_6/1.html

[blindtrevor]

Yeh - I know... sorry, I should have been clearer

When I said, don't worry about the lamps, I meant because I had thrown them in roughly where they needed to go - they haven't been connected properly yet - I had only just started adding them in

I got into a conversation with someone last night who seems to think the relay won't latch because of the voltage drop across the relay while the motor and solenoid are on... I think he's wrong - he's gone away to redesign the circuit!

I'm interested to hear your and other peoples views on that?

[strantor]

Originally Posted by blindtrevor

I got into a conversation with someone last night who seems to think the relay won't latch because of the voltage drop across the relay while the motor and solenoid are on... I think he's wrong - he's gone away to redesign the circuit!

I'm interested to hear your and other peoples views on that?

It will latch. These holding circuits have been used in conjunction with motors since relays & motors existed. If your relay coil was in series with the motor, then you would have a problem, but it's not. How does he propose to redesign the circuit in such a way that the "theoretical" dropping out of the relay will not happen? Any way he does it will require a relay to latch at the same time the motor is running.

[strantor]

I'll beat this dead horse 1 more time...

I hope you don't mind, but I've taken the liberty of converting your schematic to Ladder form. In doing so, I uncovered 2 departures from convention & one more redundant relay. I did not catch these errors in your schematic because the format is not conducive to my understanding.



You'll see I've circled SW1 & SW2 - these 2 float switches are positioned between the relay coil and neutral. This is bad form. The convention is to always have one side of the relay coil connected to neutral. This is especially important in DC circuits, as the collapsing field of the relay coil will arc across upstream contacts and burn them out prematurely.

I've drawn a line between RL2 coil and RL2 N.O. contact; as you can see, RL2 is not needed. You could simply go through RL1 N.C. contact, through SW3, and then to RL3 coil.

BTW, Do you mind if I use this thread as part of my tutorial?

[strantor]

Originally Posted by mcgyvr

Oh yeah because everyone understands relay/ladder logic diagrams..

Originally Posted by strantor

Well they should; it's about the most elementary way to draw it short of filling up a page full of relay symbols and playing connect the dots.

Originally Posted by blindtrevor

@strantor - I'm not 100% sure on the ladder logic! (at least I'm honest!)
Can you draw it in a standard schematic circuit diagram at all? Many thanks everyone

Originally Posted by CDRIVE

The comment by wayneh not withstanding, (it's true) I find this funny! It certainly gets your ladder vs conventional schematic point across vividly.

Originally Posted by strantor

I'll beat this dead horse 1 more time...

... Do you mind if I use this thread as part of my tutorial?

http://forum.allaboutcircuits.com/showthread.php?t=69884

[blindtrevor]

Originally Posted by strantor

http://forum.allaboutcircuits.com/showthread.php?t=69884

Oh - sorry... feel free!!

I've had some stuff happen that's taken my mind away from this project for a short while... but I'll be back on it soon enough!