battery operated timer for lorentz well pump?

[Oly]

Hello, I'm planning to pump water out of a cistern to a drip irrigation system. I've sized a Lorentz pump/panels to give me the psi I'll need. My problem is, I'm off-grid and need a way to tell the pump when to come on/off.  (my crop will want to be watered twice a day for ~ 2 hours each time).  I'm in need of some battery operated timer that can tell the lorentz controller (ps-600) when to turn on/off. It would be easy if I had AC, there are lots of timers that would put out the signal I need. But I'm not finding the answers I need for a battery-operated timer. Anyone have any experience with this or ideas?  Thanks, Oly

[ghurd]

Experience yes.  Good experiences, no.

The standard DC timer is very sloppy.

The standard 555 timer is Super-Extra sloppy.

The standard AC timer from a small inverter is sloppy.

I heard good things about an AU timer, but can not find it again.

I would be interested too.

G-

[jacobs]

You might look into a battery operated Intermatic timer controlling a relay. I purchased a model SS7 several years ago from Home Depot that is rated 4 amps @ 12 vdc or 2 amps @ 28 vdc.

[Ungrounded Lightning Rod]

Panels directly to a pump?  No storage?

Does the pump have "turn off if the water valve is off and pressure is high" functionality?

There are battery-powered self-timed valves specifically for irrigation control.  Put 'em on a hose bib and they provide one or two-separately-controlled hose bib outputs.  (You can expand your hose bib with a manifold, too.)

So if your pump is OK driving water pressure most of the day into a closed valve (for instance: if it shuts itself down once the pressure is up and holds the pressure with a check valve) you can use this stuff and reduce it to a previously-solved problem.

They're available at Ace hardware (at least) here in CA.  I suspect they're available in a lot of other places, too.

(They use a motor controlling a rotating valve.  So it might not be trivial to tear 'em open and convert 'em to providing an electrical "turn on/turn off" output.)

= = = =

I think there are also battery-powered quartz-clock-timed versions of the multiple-zone controllers for lawn/irrigation sprinkler valves, to be used in places where line power is not available.  Such controllers usually also have a "turn on the pump" output that goes on (to drive a power relay) when any of the valve-open outputs is on.  Those would be far closer to what you want, letting you program your watering cycles more easily.  (They are also compatible with a rain detector to save power - or ground water and pump wear - when you don't need to water because nature did it for you.)

[jacobs]

Update: Intermatic discontinued their model SS7 a couple years ago due to cold weather operation. Their present model ST01 has the same dc ratings as the SS7 and is supposed to be ok in the cold.

[dnix71]

If this is a true low flow drip system, it might be easier to fill a tank and let gravity do the work. I use an Intermatic wind up timer from Home Depot to control a pump that runs on ac. We are only allowed to water certain hours because of drought, so I turn the timer on, throw the knife switch to the pump and walk away.

The windup works up to 12 hours.

[la7qz]

Hi

Get a battery operated timer/thermostat for heating or airconditioning. Set the cut-in / cut-out temperature ridiculously high or low so the pump will only be controlled by the timer and not by the temperature.

It'll run for ages on two penlights or forever if you have a solar charged 12V (or whatever) battery available and add a 3V voltage regulator.

Owen

[Chuck]

Hi Oly,

I use a Dankoff (now Lorentz) submersible pump to supply water for house and garden. I don't know if it's the same controller, but it appears pretty similar from what I can tell. The controller is an mppt device that converts 48vDC + to 60hz 60vAC (3 phase I think) for the pump. Generally, the more panels, the more pressure the pump provides.

I would think a battery operated timer from the hardware store wired to interrupt/connect the power from the panels would do the trick as long as you don't mind changing batteries every month or so.

Another way is to wire the timer to the controller's shutdown circuit, where the tank float switch would normally go. I think this might be logically backwards (shorted is off ?) but that would take some experimenting to see how to set the timer.

[Oly]

Ghurd, can you explain more about the timers you mention? Do they provide the Lorentz the signal it is looking for but just sloppy on timing? I can deal with (somewhat) sloppy timing.  What kind of power do they need?

Jacobs: So if I understand correctly, with the SS7 or ST1 I would need to provide power equal to 4amps at 12VDC? That's do-able. It's a fair amount of power but not unreasonable. I guess I'm hoping to find a lower power solution.

ULR, I wouldn't want my pump pumping against a closed valve all day, so I want a timer to tell it when it's time to pump.  You mention a battery powered quartz clock timer. Do you know the output of these? Is it a pulse or a continuous signal and would it be compatible with what the Lorentz controller is looking for for input?

dnix71, yeah, gravity would be ideal but the field is only a few feet lower than the cistern, and about 600 feet away, so there won't be enough pressure.

la7qz, that sounds like a good solution, but like for ULR do you know the output signal and would it be compatible with what the Lorentz controller is looking for for input?

Chuck, I didn't know the Lorentz controller converted the DC into AC. That's interesting. Yes, for my system, the more panels the more pressure. As you say, wiring a timer to the shutdown circuit is the way to go; do you have any experience doing that? Do you know what the output of the timer needs to be (volts, amps ??) in order for the Lorentz controller to respond?

Thanks everyone for your responses, very helpful!

[jacobs]

Both the SS7 and ST1 are battery operated. The SS7 is powered by one internal AA battery and the ST1 by an internal lithium battery. Batteries last for several years. These timers will switch a maximum of 4 amps @ 12 vdc or 2 amps @ 28 vdc.. If you are switching more current than this, you'll need to have the timer control a relay that will then switch the higher current.

[Volvo farmer]

Why are you using a $1500 deep well pump to move water out of a cistern? I also have a Lorentz, but it is where it belongs, at the bottom of my well. To pressurize the house, we have been using a Shurflo RV type pump to move water out of the cistern. The Shurflo only costs about $50 and can be purchased in 12V or 120V configuration. Ours has suppllied all our domestic needs for 3 years now.

[zap]

Oly,

Here's a solar powered irrigation control from a craigslist listing.  I'm not sure where you live but they might be willing to ship it.

http://denver.craigslist.org/bfs/1181784420.html

It's probably similar or the same as the one Ungrounded Lightning Rod was talking about.

I wouldn't describe $195 as cheap but it's cheap compared to some of the list prices I saw.

Here's a site that lists it as having "pump control".

http://www.mrdrip.com/leit1.htm

And I think this is the company's site.

http://www.digcorp.com/LEIT_Controllers/106-LEIT_X

[Chuck]

Oly,

There is no output necessary for the timer. It needs to simply open or close the circuit to turn the pump on or off.

Normally a simple float type switch is attached to this spot via two screw down connectors. The float is a plastic bulb with a metal ball in it on a long cable with two wires. When the float hangs down (low water in the tank), the ball is at the far end of the bulb (open circuit). When the float changes position (water high in the tank) the ball rolls to the other end of the bulb (where the cord is attached), touches the contacts, completing the circuit and the pump turns off.

I have wired a switch into the line to bypass the float so I can turn the pump on before the float does it for me. It is a simple on/off switch that opens the circuit.

[dnix71]

There is a relay kit for that controller, made to run a pump. About halfway down the page. The LEIT is made in California and meets their gov't standards. Expensive, but where water is precious, it makes sense.

http://www.mrdrip.com/leit3.htm

[Ungrounded Lightning Rod]

You mention a battery powered quartz clock timer. Do you know the output of these? Is it a pulse or a continuous signal and would it be compatible with what the Lorentz controller is looking for for input?

I only know of them vaguely.  I'd have to research it.

Others here have pointed out some viable solutions:  in the $100-200 range for a purpose-built device down to less than $50 for the thermostat hack.  I'd go with one of those.

[rossw]

Our local suppliers have this little critter which looks like it would do your job easily too.
Specs say: * 12VDC supply voltage. Switching capacity: 16A @ 240VAC
http://www.jaycar.com.au/ShowLargephoto.asp?id=10216&IMAGE

[pvale]

I use a little 12VDC timer that I bought from Backwoods Solar a couple of years ago. It's a 7 day timer and all digital. I use it to turn my 2 meter radio and a couple of scanners on and off. I believe it's made by Deihl. Sort of expensive ~$40 if I remember right. Other suppliers may also have it. Keeps exact time, never have to fool with it, other than set it forward and back twice a year.

[pvale]

I was wrong, it's $68 now. I use the output to run a small relay that handles the sometimes up to 15A when I'm transmitting on 2 meters at 50W. We don't want to hear the radio and scanners at night, so timer turns them all off at 10:00PM, and back on in the morning at 7:00AM.

[la7qz]

Hi

Here's another option for a cheap hack:

http://www.siliconchip.com.au/cms/A_107706/article.html

They want you to pay to access the whole article, but you can probably figure it out for yourself (or someone here can help you) once you get your hands on one and post some pics so we can figure out what voltage to supply to the timer circuit once you get rid of the high voltage stuff.

Owen

[scottsAI]

Lawn Genie-RJ4-Plus/RJ6-Plus 6-Station Indoor Timer

http://cgi.ebay.com/Lawn-Genie-RJ4-Plus-RJ6-Plus-6-Station-Indoor-Timer_W0QQitemZ320374820746QQcmdZV
iewItemQQptZLH_DefaultDomain_0?hash=item4a97d3cf8a&_trksid=p3286.c0.m14&_trkparms=72%3A1205%
7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

How is $18 delivered in USA?

Runs on two AA 18 months so far.

Lawn watering timer with Motor start. Motor start energies external relay (this is what you use). Unit expects 24vac to power the relays, not tried one on DC. The watering circuits use a triac driver (definitely needs AC), so don't use with DC. Timer handles 4 watering times a day each station with 99 min * 6 stations. No limit to how much on time per day can be setup. If on time is less than 99 min, then only need to program 1 station. Does not mater which one. The motor start is energized any time any station is ON.

Similar units have rain detection, can skip watering if its rained.

Have fun,

Scott.

[JamesJackson]

Other suggestions have been offered, and I am not too knowledgeable about this, but...

I have seen portable 12V timers - called 'deer feeders', that work on a timed schedule... not sure how good they are - or how - exactly - they work.

If you do a Google search, you'll find quite a few hits. I've seen these deer feeders in rural farm & garden stores.

Regards,

James Jackson

[JamesJackson]

I hope I don't get into trouble for posting two comments in a row, but I just got another thought - idea - on this.

I saw a fella on Make TV - who took and destroyed an old VCR recorder - and used the timer mechanism in it - and other bits and pieces - to make a 'cat feeder'. It was really a cool idea.

The actual electronics inside the VCR run off of a lower voltage (I.E. not 120VAC - but something like 12VDC), and so you should be able to use a 12-Volt battery - or whatever.

Get creative. Old - used - VCRs are at local thrift shops - and usually cost very little. They may not work to tape any shows - but they have timers in them.

In case some points that 120VAC VCRs need the 120VAC/60Hz signal to run the timers - remember that they also make 12VDC VCRs for campers - or other 12V mobile applications - and so these may be the VCRs to look for.

Good Luck!

Regards,

James Jackson  

[Oly]

Thanks everyone for comments and suggestions. Just a quick update.

I ended up getting something called Flexcharge, which is a DC powered timer. I think it's the same one that RossW suggested. And it just acts like a float switch (on a timer) to open or close the float circuit on the controller like Chuck suggested. Simple! It uses very little power, mW, so a little VW dashboard solar panel and a 12V car battery and I'm all set. My plants and I are happy now. Thanks again, Oly.

[ghurd]

NOT a flex charge.  Bite your tongue. Hard. Twice.

The VW panels are cool.

G-