Two wire remote control relays

[4pyros]

Any ideas on the most ecinomical way to control relays from 500 feet using only two wires?
This will be a 12-24 volt system using up to 500 I/O channels.

 

[Brevor]

How many relays ?

 

[large_ghostman]

Any ideas on the most ecinomical way to control relays from 500 feet using only two wires?
This will be a 12-24 volt system using up to 500 I/O channels.

could you use those cheap wireless transmitters? have a control board near the relays? or maybe RS232, 500 feet should be no problem at low speed, or have I missed something? I get the feeling I am not understanding the question correctly, so ignore this

 

[4pyros]

How many relays ?

I am looking to control sets of 32.

 

[4pyros]

could you use those cheap wireless transmitters? have a control board near the relays? or maybe RS232, 500 feet should be no problem at low speed, or have I missed something? I get the feeling I am not understanding the question correctly, so ignore this

I want to stay away from wireless, its for pyro and our current wireless systems have proven unreliable.

 

[large_ghostman]

ahhh, Yeah fair enough, I can see why wireless wouldnt be a great choice, what about RS232? you could cheat a little and use a transistor driver at the end.

 

[ChrisP58]

I would suggest RS485. It is pretty much the standard for two wire data communication in industrial environments.

 

[dr pepper]

I have done this a few times now, data over power.
For this app if the data and power for the relays (500 of them?) are through the same wires you have a bit of a tricky situation with all those switching transients, however you might be able to do something with a switched hf carrier, see:

https://electronicdesign.com/communications/simple-circuit-communicates-over-low-voltage-power-lines

Another way that works well under noisy conditions is to modulate a current carrier, one current for a 0 and another (double works well) for a 1, though this only works if the load pulls a light and contiunous load.

 

[eTech]

What type of environment?

Inside a building? In a field somewhere?

pole line?, underground cable?, coax?

eT

 

[Reloadron]

I would suggest RS485. It is pretty much the standard for two wire data communication in industrial environments.

That would be my thinking. Before I retired we did an 800' run to a new power sub station and RS485 worked out great. Something to consider anyway.

Ron

 

[KMoffett]

Have you Googled?: pyrotechnic controller circuits

Ken

 

[large_ghostman]

Have you Googled?: pyrotechnic controller circuits

Ken

You mean one like this??

 

[dr pepper]

Theres a fault on that, wrong shade of yellow.

 

[4pyros]

What type of environment?

Inside a building? In a field somewhere?

pole line?, underground cable?, coax?

eT

In a field somewhere. We use 18 gauge zip cord or lamp cord Now.

 

[4pyros]

Have you Googled?: pyrotechnic controller circuits

Ken

Dude I am a pyrotech!

 

[4pyros]

Theres a fault on that, wrong shade of yellow.

We like orange, LOL

 

[4pyros]

This is what we use a lot of now;
https://www.fireone.com/product_overview.htm
What I am after is a simple and cheep manual firing system to help with our work load on the 4th of July.
The less hand light shows we have to do the better.
I am looking for an off the shelf board that I can package for my use.
I was looking at the IP based systems from Denkovi and that got the ball rolling.
https://www.denkovi.com/product/8/daenetip2-snmp-ethernet-controller-with-24-digital-analog-i-o.html
I would use the spare wires in the cat 5 cable to carry charge voltage to the remotes battery's
in the field.
It would be nice because they provide software we could run off a laptop and we would not need a firing panel.
And so I am wondering if any one has run across any that may be useful.

 

[large_ghostman]

olimax do a web server board with 2 relays but a number of outputs, not sure how many but the boards are cheap, adding relays to the outputs would be very easy, also look to see if VELLEMAN have anything, they are very cheap and have all kinds of funny kits with relays.
how much current is needed to fire whatever you use to light the fuse?

 

[4pyros]

olimax do a web server board with 2 relays but a number of outputs, not sure how many but the boards are cheap, adding relays to the outputs would be very easy, also look to see if VELLEMAN have anything, they are very cheap and have all kinds of funny kits with relays.
how much current is needed to fire whatever you use to light the fuse?

Here is a good primer on E-Matches as we call them;
http://www.vk2zay.net/article/14
A typical all fire current is around 1 amp, I would normally design for double that.
Solid state switching is definitely preferred over relays because the destination of a shell out of a mortar could possibly bonce the relays on.

 

[4pyros]

olimax do a web server board with 2 relays but a number of outputs, not sure how many but the boards are cheap, adding relays to the outputs would be very easy, also look to see if VELLEMAN have anything, they are very cheap and have all kinds of funny kits with relays.
how much current is needed to fire whatever you use to light the fuse?

Vellman has a 2 wire kit but its only 10 relays and has a limited distance between the controller and the remote.
We like to be 500 feet from the stuff when it goes off.