Auto top off questions

how your set up running brackish dude.

i am currently seting up a system that has 5 dc valves

ive got the valve manifold set up and all threads cut. need to work out the circuit.
anyways its going like this.

they are all nc valves

1. main shut off valve to ro/di on to manifold
2. valve to main tank
3. valve to s/w change tank
4. q/t tank




EDIT:
sitting here and realized i dont need a pressure release so im down to 4 valves may use that fifth for some thing else
 
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<a href=showthread.php?s=&postid=8849271#post8849271 target=_blank>Originally posted</a> by jmait769
Jdieck â€"œ Great info as usual!:thumbsup: Sorry, but I cannot get my mind wrapped around the SPST switch, latching and it being automatic. I looked at this website for switches but not sure if I’m in the right area:

http://www.kpsec.freeuk.com/components/switch.htm

Also, I read this thread were you and BeanAnimal discussed this same subject and dngspot soldered up something on a pc board:

http://reefcentral.com/forums/showthread.php?s=&threadid=977249&perpage=25&pagenumber=1

I’m familiar with these: and will be using this to open a 12v solenoid just like this example you gave:
I will only be using 12V to power this. Any more info on this subject to clear my feeble mind would be greatly appreciated!!

Jay

dngspot was using a printed board circuit mounted micro relay which could handle up to 3A capacity, although with the capacity, it require more accurate specifications and is more difficult to mount and connect. I usually recommend something larger for longer contact life (!0 Amp capacity)

OK here is what I would recommend:

For Solenoid: look at mcmaster catalog 7877K5 12V dc coil 0.5 amp 1/8" FNPT 100 psi max pressure
http://www.mcmaster.com/
You will need two John Guest connectors 1/8" MNPT by 1/4 tubing for it

For relay I would recommend the following:
From RadioShack PN 275-218 12VDC coil 10A contacts DPDT
http://www.radioshack.com/product/i...&cp=2032058.2032230.2032277&parentPage=family


For the auto/manual you can use a spst switch or even better a momentary push button like the following:
Mini SPST 0.5-Amp Momentary Switch4-Pk. Normally Open PN 275-1547

http://www.radioshack.com/product/i...58&kwCatId=2032058&kw=relay&parentPage=search

For the floats you can use:
The Reef Fanatic ones if to be used in an RO/DI reservoir
http://www.premiumaquatics.com/Merc...D&Product_Code=RF-RFLCFS&Category_Code=Dosers
This float has a plug in connector like the one used for earphones so you may need to get the femeale plug ins from radio shack or cut the connector and wire them directly.

or these with snail gards if to be used in the sump
http://autotopoff.com/products/DT1/index.htm

For a single power supply this will do:
12V/1000mA AC-to-DC Power Adapter Radio Shack PN 273-1776
http://www.radioshack.com/product/i...032056.2032136.2032153&pg=2&parentPage=family

For lights you can use 12V LEDS Red for activated and green for cirsuit powred.
Radio shack Part Numbers 276-270 (Red) 276-271 (Green)

http://www.radioshack.com/product/index.jsp?productId=2062568
http://www.radioshack.com/product/index.jsp?productId=2062569

I'll re-draw the circuit for a single power adapter and post it later.
 
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I'll re-draw the circuit for a single power adapter and post it later.

OK jdieck - that would be great! I'll update the picture I posted earlier to reflect what you post so that no one copies my poor effort above and I appreciate the list of items!! That really helps. Thanks again,

Jay
 
Try to enclose the float inside a piece of PVC to keep the water disturbances down. The floats should have a built in hysteresis so I don't think it's necessary to add a second float for that purpose. In my 125gal I get a few hours before float triggers and I evaporate 3 gal/day

Instead I would like to see the 2nd float used as a backup float in case the main one shorts.

Also you guys need to put clamping diodes/zeners across the coils or you'll have the float fail prematurely!!!!
 
<a href=showthread.php?s=&postid=8853878#post8853878 target=_blank>Originally posted</a> by xrunner1234
Try to enclose the float inside a piece of PVC to keep the water disturbances down. The floats should have a built in hysteresis so I don't think it's necessary to add a second float for that purpose. In my 125gal I get a few hours before float triggers and I evaporate 3 gal/day

Instead I would like to see the 2nd float used as a backup float in case the main one shorts.

Also you guys need to put clamping diodes/zeners across the coils or you'll have the float fail prematurely!!!!

with 12vdc?

what do you mean by premature?

would one need to accross a solenoid coil also?

ive had mine for about 3-4 years.
 
xrunner1234 â€"œ I kind of got the thread off topic as I was working up a system for a tank connect to the RO/DI unit. I have a 20 gallon tank I want to fill but only when it gets to the low switch then stop at the high switch to reduce the RO/DI unit from cycling on and off. Like this example from jdiecks reservoir:

18470floats2.jpg


I’m no electrical engineer but do you think those clamping diodes/zeners are necessary for a 12V system? Thanks,

Jay
 
OK guys here is a more descriptive diagram for those not familiar with electrical drawings.
In this diagram I have included the diode although I still consider it optional. I personally think that the recommended relay is fast enough at 12 volts that the transient will not damage a good quality reed switch rated for the usual 500 ma with a load of 130 ma coil. In any case it is not expensive, (two for 79 cents) easy to find and easy to install so it might extend the life of the floats or be able to operate without problems even with less quality floats.
I have been operating my system for two years without the diode with no issues but I have had a couple of consultations regarding fused floats do go for it guys.

http://www.radioshack.com/product/i...D/Product+Type/Diodes&fbc=1&parentPage=family

When installing the diode just insure to get the right polarity (direction) In the diagram below the red line is the positive it connects to the diode on the side that has the silver stripe.

A diode is not required across the solenoid; the 12 V adapters are usually designed to take that transient and the contacts of the relay have a high capacity of 10 Amp. so no problem there.

In case the system fails, to prevent a flood remember to install a mechanical float at a level slightly higher than the higher float.
(See the pic of the reservoir above.)

Here is the diagram:
topoffdescriptive.gif


As usual if you are not sure of what you will be doing then just get the $90.00 bucks, save yourself the hassle and order yourself one already made.
http://www.premiumaquatics.com/Merc...ROD&Product_Code=RF-RFLC&Category_Code=Dosers

Enjoy!
 
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another diagram

another diagram

Since I am a visual learner and want to make sure I am understanding how the 2 switch system works with the pump kicking on by the lower switch and off by the upper switch I made this basic diagram of the wiring. It does not include the diode, just the basic wiring as I understand it.

Below is how I'm understanding how to wire the setup:
relay_diagram.gif


This seems simple enough. Now if one wanted to add a 3rd switch as a safety to this system, could they not add it above the top switch (the top level off switch), thus if either of the bottom 2 switches failed the top switch would cut off power to the relay?

Here is a diagram of my current setup where the bottom switch basically controls the pump and the water level:
my_relay.gif

With this setup with any change in the water level it activates the pump, so it cycles on/off sometimes several times in an hour.

Again, I just want to make sure I understood correctly before I looked at changing anything. I like both ideas, but I'm leaning towards changing it to where the bottom switch turns it on and the top switch turns it off. This is for topping off my sump, so space is at a premium as well so I'm not sure I want to add a larger float valve in there. I would rather use the electrical float switches and control the pump, so maybe I need to get another float switch.

Thoughts??

Thanks,
Rick
 
Re: another diagram

Re: another diagram

<a href=showthread.php?s=&postid=8854873#post8854873 target=_blank>Originally posted</a> by medic29
Since I am a visual learner and want to make sure I am understanding how the 2 switch system works with the pump kicking on by the lower switch and off by the upper switch I made this basic diagram of the wiring. It does not include the diode, just the basic wiring as I understand it.

Below is how I'm understanding how to wire the setup:
relay_diagram.gif


This seems simple enough. Now if one wanted to add a 3rd switch as a safety to this system, could they not add it above the top switch (the top level off switch), thus if either of the bottom 2 switches failed the top switch would cut off power to the relay?

Again, I just want to make sure I understood correctly before I looked at changing anything. I like both ideas, but I'm leaning towards changing it to where the bottom switch turns it on and the top switch turns it off. This is for topping off my sump, so space is at a premium as well so I'm not sure I want to add a larger float valve in there. I would rather use the electrical float switches and control the pump, so maybe I need to get another float switch.

Thoughts??

Thanks,
Rick

Great and simple diagram!.

Yes if you want to add redundancy to the high level, just add a third float in series between the adapter and the high level switch and install it a bit higher than the high level switch.

Notice that this will only backup the higher level switch but will not backup the solenoid itself. If the solenoid is the one getting stuck (not the high level float) then there will be overflowing.

If you want to connect the diode following your drawing the positive is on the right (right?) so turn the diode around and connect the diode banded side to terminal number 8 instead of number 7
 
jdieck â€"œ Sweet!! That is perfect! I’ve updated that picture I posted on page one. Appreciate you clearing this up and sharing your knowledge.:thumbsup:

Jay
 
<a href=showthread.php?s=&postid=8853956#post8853956 target=_blank>Originally posted</a> by douggiestyle
with 12vdc?

what do you mean by premature?

would one need to accross a solenoid coil also?

ive had mine for about 3-4 years.

Inductive spikes that are generated when the relay closes can be in excess of 100+ volts. The problem is that's it's hard to define what that peak will be. Relay close time and inductance dictates the peak of that spike. The voltage spike will degrade the float.

On one float, I measured 150V (if my memory serves me correct). But I've seen higher on power relays with FETS as switches instead of relays.

For signal relays a diode is fine but a 20-30V zener/diode or zener/zener combo is better.

Check out some of the diode suppression techniques- http://relays.tycoelectronics.com/kilovac/appnotes/fig48.asp
 
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<a href=showthread.php?s=&postid=8853998#post8853998 target=_blank>Originally posted</a> by jmait769
xrunner1234 â€"œ I kind of got the thread off topic as I was working up a system for a tank connect to the RO/DI unit. I have a 20 gallon tank I want to fill but only when it gets to the low switch then stop at the high switch to reduce the RO/DI unit from cycling on and off. Like this example from jdiecks reservoir:


I’m no electrical engineer but do you think those clamping diodes/zeners are necessary for a 12V system? Thanks,

Jay

It's a bad design practice (and I would be embarrassed as an Engineer in the analog power field- no offense to anybody.) to present a schematic with circuitry that has relays without some sort of supression. If you're in the process of building it now then put it in.

Use 2 x 20V zeners back to back as shown in
http://relays.tycoelectronics.com/kilovac/appnotes/fig48.asp
 
<a href=showthread.php?s=&postid=8854501#post8854501 target=_blank>Originally posted</a> by jdieck
OK guys here is a more descriptive diagram for those not familiar with electrical drawings.
In this diagram I have included the diode although I still consider it optional. I personally think that the recommended relay is fast enough at 12 volts that the transient will not damage a good quality reed switch rated for the usual 500 ma with a load of 130 ma coil. In any case it is not expensive, (two for 79 cents) easy to find and easy to install so it might extend the life of the floats or be able to operate without problems even with less quality floats.
I have been operating my system for two years without the diode with no issues but I have had a couple of consultations regarding fused floats do go for it guys.

http://www.radioshack.com/product/i...D/Product+Type/Diodes&fbc=1&parentPage=family

When installing the diode just insure to get the right polarity (direction) In the diagram below the red line is the positive it connects to the diode on the side that has the silver stripe.

A diode is not required across the solenoid; the 12 V adapters are usually designed to take that transient and the contacts of the relay have a high capacity of 10 Amp. so no problem there.

In case the system fails, to prevent a flood remember to install a mechanical float at a level slightly higher than the higher float.
(See the pic of the reservoir above.)



As usual if you are not sure of what you will be doing then just get the $90.00 bucks, save yourself the hassle and order yourself one already made.
http://www.premiumaquatics.com/Merc...ROD&Product_Code=RF-RFLC&Category_Code=Dosers

Enjoy!

Actually the faster the relay, the higher the spike. And it's not the current rating of the switch but rather the voltage rating. Those little spikes can cause the contacts to deteriorate.
 
<a href=showthread.php?s=&postid=8856261#post8856261 target=_blank>Originally posted</a> by xrunner1234
Actually the faster the relay, the higher the spike. And it's not the current rating of the switch but rather the voltage rating. Those little spikes can cause the contacts to deteriorate.

What I meant by fast ... When using only a rectifier diode as a suppressor although the float switch is protected it slows down the opening of the the relay contacts thus increasing the chances of the relay contacts geting damaged by the effect of sparking during the slow opening created by the supression but, given the actual opening speed even slowed down (which will be about 10 milliseconds rather than 1 or 2) and given that the involved loads are 1/10th to 1/20th of the rated voltage/current of the relay contacts there will be no problem with the slow down using a diode alone.
Why I elected a diode only?, well, given the fact that I can go and get it from my Radio Shack around the corner has something to do with it but for anyone out there that can get a pair of 20V or 24V Zenner Diodes then go for it, the additional cost might also be superminimal.
In any case I still think that becaause the proportion of loads being used in proportion to the rated capacity of the components, even running without suppression will not be a problem at all. Now if you are planning to use a similar relay to turn on and off your Metal Halides at 7 Amperes and 120 volts, then by all means adecuate suppression which does not affect the realy speed (Like dual zenners or a zenner and a rectifier) is a must.
 
<a href=showthread.php?s=&postid=8857072#post8857072 target=_blank>Originally posted</a> by douggiestyle
is this only needed for relay coils?
or would a diode be required for solenoid valves as well?
On a DC solenoid there will be a similar effect but here note that the relay contacts are rated for 10 AM 125 VAC (About 1,250 Watts) to run a solenoid at 12 VDC 0.5 Amp (Only 6 watts) so those contacts will not get affected even if the transient peak is very high.
 
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