Anyone have a diagram for a latching system?

[phisigs79]

Try to do a DIY autotop with a latching system hooked up to a solanoid. Anyone have a diagram or pics?

[lanman]

Try to do a DIY autotop with a latching system hooked up to a solanoid. Anyone have a diagram or pics?

 

I still don't know what you mean by a latching system...

 

bob

[zygote2k]

+1 on what is a latching system, If you want to see a good bracket for an ATO, look at the video and pix of the one for sale at BRS.

[geofloors]

A latching relay is a relay which when turned on it will stay on until something triggers another relay to turn it off. Basically 2 relays built into one unit which has a "latch" to keep one relay on with out using energy.

 

I was going to use this method to top off my freshwater reservoir but decided to use the same 2 float switches and program it to my ACIII.

 

 

George

[Origami]

A latching relay is a relay which when turned on it will stay on until something triggers another relay to turn it off. Basically 2 relays built into one unit which has a "latch" to keep one relay on with out using energy.

 

I was going to use this method to top off my freshwater reservoir but decided to use the same 2 float switches and program it to my ACIII.

 

 

George

 

There are latching relays that do this, I believe. But it sounds like you've got it covered now, right?

[phisigs79]

i am pretty sure i have everything i need minus a float switch but need to know how to wire it

[Origami]

You mean, how to wire the float switch? What components are you planning on using? A float switch is typically a magnetic reed switch which either closes or opens in the presence of a magnetic field. There's a magnet in the float that as it raises and lowers, opens or closes the switch. Many float switches are configurable with respect to their behavior. That is, you can flip the float over and reverse the behavior of the switch. You could also just flip the whole switch over and get the same behavior, I suppose.

 

You can tie float switches in series to get the desired behavior. For example, two float switches can be set inside your sump so that one is an inch higher than the other. They can both be set up so that they open when they are floated in high-water and are closed when they are in low water. If both switches were wired together and triggered power to a top-off pump, then the pump would operate when the water level were lower than both float switches. Why the top switch? Well, the top switch, in this case, is a safety measure. It is, in most cases, always closed because the water level is below it and pump operation is dictated by the state of the lower float switch. However, should that lower float switch fail to actuate (say a snail got on it and interfered with the sliding of the float), the second switch would be there to prevent your topoff pump from just pumping everything at its disposal into your tank.

 

Similarly, you could add a 3rd switch that triggered when your topoff water reservoir was drained. This would, if wired correctly, could cut power to your pump if there was no water to pump (possibly saving your pump from burnout).

 

Another consideration is whether to wire 120VAC through these float switches or to use low voltage DC or AC through the floats and to trigger a relay that would handle the regular household line voltage. I am more comfortable with the latter. Though more complicated, it keeps you from having DIY 120VAC wiring in contact with your tank and, possibly, top off water. This would probably not apply if you were using your ACIII to do the job.

 

To wire the float switches to your ACIII, you'll (nominally) have to use the low-voltage inputs that are available one one of the interfaces I think it's the "Input Connector." This connector, as I recall is already wired so that they detect a connection between one of the inputs (Input #1 or Input #2) and the Ground wire. Wire up your float switches in the series configuration that give you the desired response, and tie the two leads of the overall assembly between one of the inputs and the Ground pin. This should give you the ability to detect the need for top-off water and trigger a pump's operation.

 

For example, let's say that you have three float switches and that you're going to put 2 of them in your sump (one higher than the other), let's call them Switch 1 and Switch 2, and one in your top-off container (called Switch 3). Let's also say that you want to operate your top-off pump when the water level is lower than both the two switches in the sump (#1 & #2), but not when the top-off container is empty (that is, the water level is below Switch 3). In this case, you would configure Switches #1 and #2 to be closed when the water level was below them, and Switch #3 to be open when the water level was below it. You would then wire all three switches in series, daisy-chaining them. It doesn't matter which wires you tie together, just that they're chained. The final assembly then has two unconnected wires remaining. One comes from Switch 1 and one comes from Switch 3. These two wires would tie into the ACIII Input Connector at the Input #1 and the Ground pins. By reading Input #1, you'll be able to sense the state of the three switches. If the overall circuit is closed, you operate your top off pump; if it's open, you don't operate your top-off pump.

 

This is probably complicated to put in words like this. I'll likely do something similar as I bring my ACIII on line over the next few weeks. (I do have to make the decision on whether or not I even want my ACIII to control top-off or just have a separate system doing that job to distribute the risk, but that's another story.) In any case, I hope this helps some.

[phisigs79]

I need a diagram. I am tryting to put two float switched in my RO top off tank and hook them to a solonoid hooked to my RO water main. Want to have a lower and upper switch where it cuts on when the water level is low and cut off when it reaches the upper float switch when full.

[Origami]

Here's an idea that I think does what you're asking. Realize that if the top switch fails, your ATO reservoir will overflow. Because you want basically a refill function to be controlled by your ACIII, I don't see any reason why you shouldn't use both discrete switched inputs that are available to you. This solution uses both.

 

 

I'm not an experienced ACIII programmer yet so here's a lame attempt at some pretty simple code. Keep in mind, I may have this wrong....

 

//Let SOL# be the power to the RO/DI solenoid assigned to address D01.

//Switch1 is the first discret input to the ACIII. It is connected to a float switch that is open when the float is floating, and closed when the float is not floating.

//Switch2 is similar to Switch1.

//Switch 1 signals max level in the ATO reservoir.

//Switch 2 signals min level in the ATO reservoir.

 

SOL# = D01

 

If Switch2 CLOSED Then SOL ON (If the water is low, then turn the solenoid on)

If Switch1 OPEN Then SOL OFF (Once the reservoir is filled, turn the solenoid off)

Edited January 15, 2009 by Origami2547

[phisigs79]

I do not have a AC3. This can be done using a relay but i need a diagram for wiring

[Origami]

Darn it. Sorry Chris, I had read Geofloors post before.... Let me see if I've got an idea for a relay implementation.

[dbartco]

I typed into google, "ATO latching schematic" and got good results. I'd post, but don't want to take that surfing fun away from you.

[Origami]

Chris, here's a thought that uses a 120VAC SPST NO (normally open) relay configured to latch when SW_bot (which is the float switch monitoring for low water level) is closed and to reset when SW_top is opened. Both float switches are oriented the same. That is, both are closed when the float is not floating. "Pump" could just as well be your solenoid. H and N are 120VAC Hot and Neutral respectively:

 

 

The circuit state as drawn represents the state when the reservoir is full. In this case, both SW_top and SW_bot are open, as are the relay contacts. Consequently, the relay is not active and is open.

 

As the water level in the reservoir is drawn down, SW_top closes thereby connecting AC neutral to one side of the relay coil. However, the other side of the coil remains open and the relay is not active (contacts are open).

 

When the water level reaches below the lower float switch, SW_bot is closed. This establishes a connection between AC hot and the other side of the relay coil. The relay is now charged and the contacts close to latch the relay in this state. The "pump" is then turned on since it now has power applied to it.

 

As the water level in the reservoir rises, SW_bot opens. However, since the relay contacts are closed, the relay is latched in this state and water continues to fill the reservoir.

 

When the water level reaches SW_top, the float switch monitoring the top of the reservoir, SW_top opens. This removes power from the relay coil and the relay contacts open. At this point neither end of the relay coil is connected to AC hot or neutral. The circuit is now in the original state.

 

One downside for this notional design is the proximity of AC to the water. You have to make sure this design is sealed well. Similar implementations are possible using low voltage DC but you would probably need a DPST (double pole single throw relay) and a DC (wall-wart) power supply. Topology is similar except that the "pump" would be controlled by the second, separate pole of the relay. The wall wart would supply power between the H and N leads and you might (if it weren't built into the relay) need a flyback diode placed across the relay coil to clamp inductively induced voltage spikes when the coil is de-energized.

[Origami]

I typed into google, "ATO latching schematic" and got good results. I'd post, but don't want to take that surfing fun away from you.

 

[phisigs79]

i found one online and maybe i dont understand it but i guess it would help to see a actual pic of the relay hooked up. Im no electrical engineer by far

[lanman]

I need a diagram. I am tryting to put two float switched in my RO top off tank and hook them to a solonoid hooked to my RO water main. Want to have a lower and upper switch where it cuts on when the water level is low and cut off when it reaches the upper float switch when full.

 

Now I understand... is the solenoid powered by 120v??

 

What kind of a relay do you have? Or will you need to purchase one?

 

bob

[phisigs79]

solenoid is powered by 120v might have to purchase a new relay since i am pretty sure mine wont do what i need it to. i have a 12v power adaptor and project box and one float switch

[Origami]

One float switch? You're still going to get a second, I suppose? (Since you mentioned above that you needed a design using two float switches - one at the top and one at the bottom, I'm assuming that you're planning on getting another.) Since you've got parts, let's start this again with an understanding of what you have on hand. Do you have a relay or not? If so, who is the manufacturer and what is the part number (it may be printed on the relay). This is useful as it will help me get data on the coil voltage, contact ratings, and pinout. I assume that the 12V power adapter is a wall-wart (transformer cube that plugs into the wall)? What specs are printed on it (namely the output voltage and current rating)? Do you have access to other parts or are we talking about sticking with Radio Shack inventory? Where were you planning on getting a second float switch?

 

Also, if you found one online that you think is close, post a link and I'll tell you what I can about it.

Edited January 16, 2009 by Origami2547

[phisigs79]

I am going to order a float switch from ebay. I need to pick this relay http://www.aquahub.com/store/12voltspdtrelay.html This is what i bought

http://www.wamas.org/forums/index.php?act=...post&id=252

[Origami]

Here's a modified idea, Chris, that uses your 12VDC wall wart, two float switches, and the DPDT relay that you linked to above. You'll have to get enough information about the pinout of the relay to be able to determine the wiring, but I can tell you this from looking at the component: If you'll notice, the relay has 8 flat, blade-like pins. This relay is configured to be a DPDT, or double-pole double-throw. That means that there are two switches (double pole) inside that switch a common signal between one of two different contacts (double throw). This means that each switch has three pins associated with it or, since there are two switches in this relay, six pins total. Each switch has a common pin and two other pins. Of the other two, one is "normally open" and one is "normally closed." When the relay is not energized (that is, there is no power applied to the coil), the "normally closed" pin is electrically connected to the common pin, and the "normally open" pin is not. This relationship is reversed when the relay is energized. Now, I suspect that the six pins that are arranged in one manner on the body of this relay correspond to the connection points for these two switches. The remaining two pins on the outside of the relay undoubtedly correspond to the two pins of the coil.

 

In the modified design, one relay switch is used to latch the relay state and the second is used to provide 120VAC to your solenoid. If you try to match your components against the drawing, I think you may be able to figure out what goes where. If not, I'm willing to help however I can. If you find another implementation that you want to consider, post it and I'll be happy to take a look.

 

You'll notice by the way that I don't use the small relay that you currently have on hand in the modified design.

 

Edited January 16, 2009 by Origami2547

[phisigs79]

I think i finally understanding the diagram. Need to go to radio shack for a new relay

 

Edited January 16, 2009 by phisigs79

[Origami]

I think i finally understanding the diagram. Need to go to radio shack for a new relay

 

 

Almost, but it shows me that you've just about got it. I think there may be some error in the wiring that you're showing. See that top view of the relay on the left? See how it has a diagram printed on it? I think this probably corresponds to the pinout of the device. If I had to guess, the two columns of three pins (the smaller ones) correspond to the two switches. One column is one switch. The other column is the second switch. As drawn, the pin closest to the pins that drive the coil is the common lead for the switch. The one farthest away from the coil is the NC contact as you've shown in your diagram.

 

If you'll notice, in my diagram, signals don't cross between the relay switches. For example, the 120VAC signal transits only one switch, not both. In your diagram, it looks like the 120VAC crosses the relay from left to right - across columns, and therefore across switches.

 

Here's an update based on your components shown. The relay looks to be an Oko K41DS2C12. It's a 12VDC relay with a 160-ohm coil. Contacts are rated at DC 10A at 28V, and AC 10A at 250V. The diode shown is a flyback diode that is intended to clamp transients across the switches when coil current is interrupted. It can be just about any diode such as a 1N9001 or even a 1N4001. I've probably got some lying around someplace, but you can probably find either at Radio Shack for next to nothing. The direction of the diode is important. Normally there's a black band or stripe on the end known as the cathode. You want to put this end on the positive side of the 12V supply and the other end on the negative side. You can probably get away without it, but using it will be more reliable.

 

[DaveS]

Wow, I know with my EE degrees that stuff should seem cool but it makes my head hurt. Here's an approach I found that doesn't involve an afternoon sniffing hot solder. Maybe it will accomplish what you want.

 

 

The idea here is that the inner tube stays full until the water level in the reservoir drops below the lower end. Once that happens all the water falls out of the inner tube causing the float switch to activate. Water then comes in and the level for both the reservoir and inner tube fills up at the same time until it hits the float valve. The check valve is there to allow air inside the inner tube to escape during filling. I hope this makes sense.

[Origami]

Wow, I know with my EE degrees that stuff should seem cool but it makes my head hurt. Here's an approach I found that doesn't involve an afternoon sniffing hot solder. Maybe it will accomplish what you want.

 

 

The idea here is that the inner tube stays full until the water level in the reservoir drops below the lower end. Once that happens all the water falls out of the inner tube causing the float switch to activate. Water then comes in and the level for both the reservoir and inner tube fills up at the same time until it hits the float valve. The check valve is there to allow air inside the inner tube to escape during filling. I hope this makes sense.

 

Innovative! I love the out-of-the-box thinking, Dave. The success depends upon the long-term integrity of the check valve, which may or may not be more reliable than a float valve, but I love the concept.

[DaveS]

I gotta be honest, I didn't invent this. But I thought it was a great idea too- good enough that I was able to actually remember it... I plan to make one of these myself as part of my redo. One other things- the "inner tube" really doesn't have to be anything fancy. It can essentially be a PVC pipe. It just needs to be big enough for the float switch and check valve.

 

Yes, if the check valve fails the apparatus doesn't work but it wouldn't be a catastrophic failure. Worst case, your RO/DI cycles more. Water will still be available for top off and nothing floods. That was one of the elegant aspects of this.