Simple newbie remote control relay wiring question

[duckfan98]

Okay,

So I am new to all of this, so be easy

I have a wvrc4 that is the remote control for a BE FM1C1 / fxi60 transmitter...I can read the analog status metering just fine, but I'm struggling with the relay functions, ie TX power on / off, raise & lower power.

How do I wire these up? The wvrc4 has the typical NO, NC and CM on each relay. For examle, the transmitter power off control is just one wire terminal....just curious how I wire the wvrc4 to control those on the transmitter? Sounds simple enough, unless you've never done it! :-[

 

[TomT]

Sounds like they don't use relays, but instead just sink the control terminal to ground. That is, when you tell the WVRC4 to turn the transmitter off, the terminal goes low--to ground, which would then tell a transmitter that uses ground switching to turn off. (E.G., a momentary ground between the "transmitter off" terminal on the transmitter's remote connection and control ground on the same connector turns off the transmitter.)

This may work with newer transmitters, but with a lot of older transmitters switch voltages rather than ground for remote control functions. If that is the case, you need to build a relay panel to interface between the WVRC4 and the transmitter--the remote control controls a conventional low voltage relay which then uses the "dry" contacts to control the transmitter.

 

[Kmagrill]

As Tom mentioned, most newer transmitters work by triggering against ground. For each function, tie ground to the CM terminal of the remote control. CM is the wiper of the relay switch. It is not necessary to make a bunch of "home run" ground connections to the transmitter. One ground wire run to the transmitter, then jumpered to all of the CM terminals will work just fine. Next, tie the appropriate transmitter control input to the N.O. relay that you are going to use. That's all. When you activate the relay, it closes its switch contacts shorting the transmitter's control input to the ground which should operate the transmitter. Of course, this comes with the caveat that you should read your transmitter book to verify proper wiring before proceeding.

Although you have the type described above, for the sake of completeness, there are two older types of commonly encountered transmitters that do not use solid state logic for switching. Many of these use 24Vac. Those can still be operated using the relays on the WVRC. Instead of bringing out the ground, you have to bring both wires associated with a particular function to the relay as pairs. The hookup is usually the same after that.

The final type of control circuit used 117 or 230Vac. I have not seen a transmitter of this type made since the late 1970s. The last one I worked on was an early version of a Harris FM20K that had more in common with the Fm20H than the K series. It is dangerous to connect lethal voltages to open terminals that can be accidently touched. Never do it unless the remote control is to be mounted entirely inside the transmitter where nobody can touch the terminals without de-energizing the transmitter first. Proper signage is also a must. The normal process for this type of interface is to build a slave relay box that will live inside of the transmitter and convert the lethal voltages into low voltages for connection to your remote control.

 

[duckfan98]

Thanks guys.

On the remote control terminal strip on the back of thr FM1C1 transmitter, there are signal grounds and chassis grounds. So I assume, run a wire from chassis ground to CM, then jumper to the rest of the CM on the wvrc4? Then a simple wire from NO on relay1 to Transmitter Off command on transmitter remote control terminal strip?

 

[frankberry]

If you have access to the transmitter manual, it will help you fill in the blanks.

 

[roynilsen]

Manual...

http://www.bdcast.bitstudios.com/information-center/manuals

 

[BobOnTheJob]

IIRC, some of the BE models take a +5V sample from the remote control terminals, which you would route through the Common terminals on the WVRC4 and then attach each WVRC4 NO terminal to the transmitter ON, transmitter OFF, power RAISE, power LOWER, etc commend terminals. If uncertain, try the above described ground method...it can't hurt anything. If that doesn't work, pulsing them with +5V through the WVRC4 most likely will.

 

[bradgoehl]

If i remember right the "C" Series is the +5v style, but as stated before the manual will tell you.

 

[BobOnTheJob]

If i remember right the "C" Series is the +5v style, but as stated before the manual will tell you.

The manual is not available unless you sign in first. Just looked at my BE FM5TS and it uses +15V from the remote control terminals...I suspect the FM1C does too.