Wireless Remote Control

GA.

I have way too many Christmas decorations on my lawn every year. I have two separate 20 amp circuits that I use for them, but turning them on and off each night got the better of me last year. I put 2 30 amp relays into a weather resistant box. two inlet and two outlet connectors. All switched by a cheap remote controller.

Sounds like a plan. Thanks.

I don't know that much about electronics, but I'm guessing the relay would have to be able to "latch" on and off so it would not be continuously energized while the DC is running?

You are smarter than you give yourself credit for- You are correct on the latching, although some transmitters provide that action themselves.

For example- the cheap PUSH ON, PUSH OFF controller for lighting circuits generate the control signal internally in their receiving box. That box contains the latching circuit.

Have fun.

It depends on the relay. The simplest ones consume enough current to overcome the force of the spring that causes the motor contacts to be "normally open".

Power on, force overcomes spring tension, contacts close, motor on. Power off, spring pulls contacts open, motor off.

The relays that I used were simple non latching relays. The latching function is built into the receiver part of the remote control system. I paid $9.99 at Walgreen's.

Most wirelesss systems I've seen only have control I/O anyway, so you're going to have to bump it up fom a remote relay for motor contactor control. If you're lucky, you could check some of the contactor suppliers. Many of them have interchangeable coils in different voltages. Either way you'll need a power supply at the working end. For the radios try Banner. Lots of I/O choices. Just depends on how many gizmos you want to put together.

Try sparkfun . you know

zigbee 2.7ghz switches .. hope this helps..

I would probably go with X10 automation stuff. They do have a heavy-duty relay based appliance module HD245, it is setup for 220V, but you could just pull the guts out and use it with standard plugs/sockets, or change the cord. Or if you want to go with a contactor, you can drive it with their "universal" module, this one just has a configurable switch in it, so it can be wired in to whatever you need. I don't know of any solution that would be cheaper. I do remember seeing a project one time where a guy build an "auto-on" device that would turn on the big dust collector vacuum when any of the woodworking tools was turned on.

A quick search did find an "off-the-shelf" solution for $60 LINK

Now here's a deluxe version you can build! LINK

I would do some more Googling, but I'd better get back to work :)

Tom D.

do engineers have a tendancy to over design?

a friend of mine needed a similar item

he bought a garage door remote and made it work

Over design? We're just never satisfied that it's as good as it can be.

Because "good enough" just ain't good enough!

lynlinch is totally correct. Just control the contactor.

The reason only 1 HP devices are available is because a 2 HP device (120 VAC) requires a 20-amp circuit, which requires a special plug AND the circuit and electronic mfrs. don't want to add a special device for only a few possible sales.

Controlling the contactor can be done with a really cheap device that can be used for lamps (or Christmas tree lights) and will sell for about $10 or less- add another $15 for the contactor relay and you are set.

I designed a wireless phone controller that activates up to 6 wireless wall modules [pressing numbers from 2 thru 7] to turn on/off 120-vac electrical devices within a 50-ft. range, from anywhere on the planet using a cell phone.

By simply plugging in an appropriate-rated 120 vac DPDT relay to one of these wall modules you can operate your equipment.

All other 'replies' seem to agree with 'relay' transfer operation. You can use any wireless light switch that costs about $15 with the relay. JFM

And let's not forget this.

Go to x10.com and look in their home automation items.

Item TM751 $12.99 is the transceiver and has a relay contact 2 wire outlet on it. Use it to drive a motor starter relay

Item KR22A is a 4 channel credit card size remote. On todays page, they were 4 of them for $19.99

You could then add 3 other modules for lights or appliances. Simple to set up and simple to use. My house is loaded with them. Let me put light switches everywhere.

Batteries are usually the wrist watch style battery and last for quite a while.

Gee, wish I would have thought of that, oh wait! I did!

_{Sorry, couldn't resist the sarcasm}

Tom D.

P.S. How's things in Coffeyville? I'm in Wichita now, but I did spend a year or two in Chanute.

'm guessing the relay would have to be able to "latch" on and off so it would not be continuously energized while the DC is running?

Latch is done by a parallel circuit whose contacts are actuated by output of main circuit.

In the assembly I made, the latching relay is the low current relay that is radio controlled. The higher amperage relays are constancy duty non latching relays.

In my assembly the DC is applied momentarily, but does latch on until the radio signal is activated again, causing the low current relay to release.