Reef Central Online Community
Neptune Systems

Home Forum Here you can view your subscribed threads, work with private messages and edit your profile and preferences View New Posts View Today's Posts

Find other members Frequently Asked Questions Search Reefkeeping ...an online magazine for marine aquarists Support our sponsors and mention Reef Central

Go Back   Reef Central Online Community Archives > General Interest Forums > Do It Yourself

 
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04/02/2006, 07:22 PM
fio1022 fio1022 is offline
Registered Member
 
Join Date: May 2004
Location: Wantagh,Long Island
Posts: 860
Auto Top-Off Schematic?

I'm looking for a schematic for an auto top off system I'm trying to build.I have two float switches and a relay,not sure how to hook it up.
I want to have the lower float set(min.level) to energize a relay coil and a upper float set(max.level) to de-energize the relay coil.
What i don't understand is when the lower float drops, the contacts close and it energizes the coil.As the float starts to rise its going to open the contacts so how is the upper float ever going to come into play?
I'm thinking a second relay but kind of confused about it.
Any suggestions or ideas how to do this?
__________________
its all about time,space,and money
  #2  
Old 04/02/2006, 07:56 PM
30mini 30mini is offline
Got frags?
 
Join Date: Feb 2006
Location: Cincinnati, Oh
Posts: 9,764
Send a message via AIM to 30mini
Why not use the second float switch in your reservior so that when it gets too low, the pump wont turn on at all?
__________________
Now, thats a deal!!!
  #3  
Old 04/02/2006, 08:17 PM
Qwiv Qwiv is offline
RainbowAcro
 
Join Date: Nov 2003
Location: Palo Alto, CA
Posts: 1,755
Send a message via AIM to Qwiv Send a message via Yahoo to Qwiv
You cannot do what you are discribing with a simple relay. You would need to creat a logic board to accomplish what you are discribing. Use the second floatswitch as a back-up.
__________________
If I knew keeping fish would be so hard, I would of had kids by now.
  #4  
Old 04/02/2006, 08:26 PM
chrisguy chrisguy is offline
Registered Member
 
Join Date: May 2005
Location: Grand Island, NY
Posts: 1,829
Send a message via AIM to chrisguy
In my experience, a float switch typically moves almost 1/4" so it does cover the low and high functions. As others stated, your best option is to use the second float switch as a backup, mounted higer of course.

I have a couple schematics in my gallery.
__________________
Chris

My son said I should have been a potatoe bug farmer.
  #5  
Old 04/02/2006, 10:39 PM
BeanAnimal BeanAnimal is offline
Premium Member
 
Join Date: Feb 2003
Location: Pittsburgh
Posts: 11,710
Quote:
Originally posted by Qwiv
You cannot do what you are discribing with a simple relay. You would need to creat a logic board to accomplish what you are discribing. Use the second floatswitch as a back-up.

Actually this can be done with a simple relay and 2 float switches. Many of us a simple "latching" circuit to run our top-offs.

The circuit is called a "latching relay circuit" and does not need any type of logic or other components (maybe a diode to protect the relay coil from iductive spikes).

A search here or on google will provide you with plenty of examples. If you still need help let us know. (This question gets asked quite a bit)
  #6  
Old 04/03/2006, 04:52 AM
fio1022 fio1022 is offline
Registered Member
 
Join Date: May 2004
Location: Wantagh,Long Island
Posts: 860
Quote:
Originally posted by 30mini
Why not use the second float switch in your reservior so that when it gets too low, the pump wont turn on at all?
I have that set up now.I'm looking to eliminate the drip reservior and go with a small dosing pump triggered dy the relay.The dripper gets clogged all the time and is getting to be a pain.
__________________
its all about time,space,and money
  #7  
Old 04/03/2006, 04:17 PM
Qwiv Qwiv is offline
RainbowAcro
 
Join Date: Nov 2003
Location: Palo Alto, CA
Posts: 1,755
Send a message via AIM to Qwiv Send a message via Yahoo to Qwiv
Quote:
Originally posted by BeanAnimal
Actually this can be done with a simple relay and 2 float switches. Many of us a simple "latching" circuit to run our top-offs.

The circuit is called a "latching relay circuit" and does not need any type of logic or other components (maybe a diode to protect the relay coil from iductive spikes).

A search here or on google will provide you with plenty of examples. If you still need help let us know. (This question gets asked quite a bit)
Um, that was what I was saying. I am old school. A circuit = logic board, unless your circuit contains no logic, in which case it doesn't work.
__________________
If I knew keeping fish would be so hard, I would of had kids by now.
  #8  
Old 04/03/2006, 05:24 PM
BeanAnimal BeanAnimal is offline
Premium Member
 
Join Date: Feb 2003
Location: Pittsburgh
Posts: 11,710
I guess I never considered a single latched relay and 2 switches as "logic" when compared to a the same relay and and 2 series switches.

In other words the only difference is the way the wires are attached to the relay and switches. Your response made it sound like "extra stuff" was needed to make such a setup work (I.E. a "logic board"). I simply wanted to make it clear that the same relay and float switches mentioned by the OP could be easily wired into a latch type setup where the bottom float starts the fill procedure and the top float stops it.
  #9  
Old 04/03/2006, 05:46 PM
aaronpentz aaronpentz is offline
Registered Member
 
Join Date: Dec 2005
Location: Holiday Inn Express or my AVIS Rental Car (Algonquin on the weekends)
Posts: 498
Do you know if your float switches are normaly open or normaly closed contacts?
__________________
"Friendship is like peeing on yourself: everyone can see it, but only you get the warm feeling it brings"
"Have you ever noticed? Anybody going slower than you is an idiot, and anyone going faster than you is a maniac."
  #10  
Old 04/03/2006, 05:49 PM
fio1022 fio1022 is offline
Registered Member
 
Join Date: May 2004
Location: Wantagh,Long Island
Posts: 860
OK,so I figured out how to wire it to be a latching relay.I knew as a "seal in circuit"but that sparked my memory.
Now that I have that figured out ,I have to decide on a pump.I was thinking of going with Aqua Medic SP 3000 Dosing Pump.I read somewhere that it may pump to fast to use with limewater.
Can anyone back this statement or recommend it.It pumps at a rate of .8gal/hour.
__________________
its all about time,space,and money
  #11  
Old 04/03/2006, 05:56 PM
BeanAnimal BeanAnimal is offline
Premium Member
 
Join Date: Feb 2003
Location: Pittsburgh
Posts: 11,710
I use a solenoid and gravity I top-off with RO/DI and dose DIY 2-part. The dosing setup is independent of the top-off and sump level.
  #12  
Old 04/03/2006, 06:54 PM
douggiestyle douggiestyle is offline
www.kandnsales.net
 
Join Date: Nov 2004
Location: MOON
Posts: 1,736
Send a message via AIM to douggiestyle
i use this set up
ro/di>>solenoid>>kalk reactor>>tank

all running on 12vdc.

--hey bean i found a use for all my ro/di waste water, the fish pond.--
hopefully no more hose.
  #13  
Old 04/03/2006, 07:01 PM
BeanAnimal BeanAnimal is offline
Premium Member
 
Join Date: Feb 2003
Location: Pittsburgh
Posts: 11,710
I have tapped into the float switch on the washer for now, but will soon have the new model maytag neptune and don't think she will be okay with me hacking into it for a few years.
  #14  
Old 04/03/2006, 09:38 PM
BruiseAndy BruiseAndy is offline
Registered Member
 
Join Date: Jan 2003
Location: Ogden ut
Posts: 872
Send a message via AIM to BruiseAndy
here
(ignore the third float which i use as a safety)



__________________
"Those who would give up essential liberty, to purchase a little temporary safety, deserve neither liberty nor safety."
  #15  
Old 04/03/2006, 09:49 PM
BeanAnimal BeanAnimal is offline
Premium Member
 
Join Date: Feb 2003
Location: Pittsburgh
Posts: 11,710
I get a chill every time I see that ladder diagram... I wonder what kind of hoops an old school otis elevator tech must have had to think through!
  #16  
Old 04/03/2006, 10:43 PM
joedirt54 joedirt54 is offline
Registered Member
 
Join Date: Feb 2006
Location: Western PA
Posts: 247
I just got a two switch DIY system with relay and I'm going to run one as the main float and use the other as a back-up high water switch. I think I'm going to buy another set to power a led(to warn me switch two is running the tank) and another led to warn me when the supply tank is low.
  #17  
Old 04/04/2006, 06:34 AM
fio1022 fio1022 is offline
Registered Member
 
Join Date: May 2004
Location: Wantagh,Long Island
Posts: 860
Thanks for the diagram.It's what I had in mind.
Whats the purpose of the pump relay?Couldn't the n/o contacts work the pump by itself?
__________________
its all about time,space,and money
  #18  
Old 04/04/2006, 07:48 AM
FuzzyLogic FuzzyLogic is offline
Registered Member
 
Join Date: May 2005
Location: South FL
Posts: 228
Here is an old schematic by BeanAnimal.


  #19  
Old 04/09/2006, 01:24 PM
Bumzyman Bumzyman is offline
Registered Member
 
Join Date: Feb 2004
Location: Central New Jersey
Posts: 57
Send a message via AIM to Bumzyman Send a message via Yahoo to Bumzyman
Wow, it dosen't get any easier then that.... Good job on the graphic!
  #20  
Old 04/09/2006, 09:56 PM
fio1022 fio1022 is offline
Registered Member
 
Join Date: May 2004
Location: Wantagh,Long Island
Posts: 860
I could buy all the parts,fabricate and preform several test runs before I could make a drawing like that with animated graphics on the computer.
What program can do that?
__________________
its all about time,space,and money
  #21  
Old 04/10/2006, 07:53 AM
FuzzyLogic FuzzyLogic is offline
Registered Member
 
Join Date: May 2005
Location: South FL
Posts: 228
Quote:
Originally posted by Bumzyman
Wow, it dosen't get any easier then that.... Good job on the graphic!
Thanks, the actual schematic was done by BeanAnimal. This topic comes up quite a bit so Bean and several other people have explained this circuit many times. For people like me, it can be hard to wrap your head around this type schematic unless you see it in action. I thought it would be nice to animate it.

Quote:
Originally posted by fio1022
I could buy all the parts,fabricate and preform several test runs before I could make a drawing like that with animated graphics on the computer.
Yep, it was time consuming. Not something I wanna do everytime I wire a relay. I used MS Paint to draw the schematic and then used a program called AdGif to animate it. I'm sure there's a more graceful way of doing it.
  #22  
Old 04/10/2006, 01:03 PM
Qwiv Qwiv is offline
RainbowAcro
 
Join Date: Nov 2003
Location: Palo Alto, CA
Posts: 1,755
Send a message via AIM to Qwiv Send a message via Yahoo to Qwiv
What is the purpose of the diode?
__________________
If I knew keeping fish would be so hard, I would of had kids by now.
  #23  
Old 04/10/2006, 01:22 PM
BeanAnimal BeanAnimal is offline
Premium Member
 
Join Date: Feb 2003
Location: Pittsburgh
Posts: 11,710
The diode is to help abosrb the back emf (inductive kick) that occurs when the relay field colapses. This will help protect the delicate reed switch in the float assembly.

Explanation:
When the power is removed from the relay, the armature is quickly shoved back through the bobbin (the coil) by the return spring. This action produces electricity. In addition the relay bobbin and armature are saturated with electrons that are released when the electromagnetic field colapses.

Any small 2n series should work.

For those interesed:
There are many relay coil supression methods... this is one will work well for our purposes. You should not that ANY supression slows down (dampens) the field collapse and therfore slows down the movement of the relay. This in turn can cause arcing at the relay contacts. This should not be a problem in our application... but HIGH VOLTAGE HIGH CURRENT applications can be affected. In those cases stronger relay springs, contact configurations and other suppression menas should be explored.

Bean
  #24  
Old 04/10/2006, 02:18 PM
Qwiv Qwiv is offline
RainbowAcro
 
Join Date: Nov 2003
Location: Palo Alto, CA
Posts: 1,755
Send a message via AIM to Qwiv Send a message via Yahoo to Qwiv
thx
__________________
If I knew keeping fish would be so hard, I would of had kids by now.
  #25  
Old 04/11/2006, 07:18 PM
fio1022 fio1022 is offline
Registered Member
 
Join Date: May 2004
Location: Wantagh,Long Island
Posts: 860
If the diode is not added as shown will the float switches eventually fail?
__________________
its all about time,space,and money
 

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -5. The time now is 12:40 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef Central Reef Central, LLC. Copyright 1999-2009