Electronics Questions

To anyone who knows electronics, I need a little help with a project. A lot of things are intuitive to me, but electronics isn't one of them. I just can't easily grasp the big picture with a complicated project. I would like to learn, but just don't have the time to dive into it

I am doing a TV lift project. I have two 12v linear actuators. One will move the countertop horizontally and out of the way of the tv. The second will lift the TV which is exposed when the countertop is no longer above it .

I am using a key switch to turn the system on. I am using rocker switches to control the linear actuators. I am planning on using magnet switches as a safety to prevent either actuator from moving while the other is in the way (the vertical actuator can't lift until the countertop is out of the way, and the countertop can't move back until the tv is down).

1) are magnet switches an ok way to do the safety? Is there a better way? I figure I'll just mount magnet switches at the end of the travel in each direction to interrupt/activate the power as needed.
2) Do I need two rocker switches? Can I use a relay to automatically turn on the vertical lift once the horizontal movement is complete? I can picture that. I can't picture how I reverse it. I assume they make a relay with multiple switches, but I can't comprehend wiring it. I also assume if I could do this, I don't need safeties.
3) I have a 120v outlet that I don't want to get power when the system is on. Can I use a relay to interrupt the power to the 120v outlet once the 12v key switch is turned on?

Thanks for any help you can provide.

Magnetic switches should work fine as long as they can handle the current. I expect you'll be controlling a relay or MOS with more current drive from the switch. Optical or mechanical switches would work as well and mechanical ones may have higher current drive.

You can use the overtravel stop switches so you'd only need one up/down switch. Exactly how this is done would depend on the overtravel stop switch.

Yes you can use a relay to interrupt power but it'd have to be a very high power relay. There are probably better options, simplest I see is a hidden light switch that gets tripped when the travel reaches end point.

You could use the magnetic switches to operate relays, either mechanical or solid state to reduce the current going through them or use industrial snap action switches with a high current rating.

http://www.grainger.com/Grainger/OMR...285?Pid=search

I would do two buttons rather than rocker switches. Use one to "deploy" and one to return. Use a magnetic switch at the end of travel for the case opening to trigger the lift. Do the opposite to close it back up. You could even use a latching relay so you could just punch the button and walk away.

I'd use a smart relay and 2 buttons. Using one you could input them directly into the inputs and use the switched (relay) outputs to control the actuators. It would be very simple to program, and the IDEC software is pretty simple when you look at the gamut of PLC type software. It is free as well. And with the smart relays, you can actually program them from the front panel as well.

You would need one of these with 4 12v inputs (button x2, prox/magnetic sensor x2), three relay outputs (one for each actuator, one for the switch), and a small 12v power supply.

http://us.idec.com/Catalog/ProductSe...lay&FamilyName

If I were at work I could draft you up a quick schematic.



Or you could also ghetto wire it with relays and 120v prox switches. Wouldn't be as clean of an install or have as few parts though.

Thanks for the input guys!