I'm working on a project where audio messages will be played back and colored LEDs will match the message. The audio playback and LEDs will be controlled via RF and/or wired buttons. My issue is that I need the relays to latch on with the button, but I also need to make sure that only one is on at a time. For example, the push button panel will have 3 buttons, and each of those buttons will be a different priority. In case the wrong button was pressed, or the priority level changes, I only need one output on at a time. The wireless receivers I am using will latch no problem, but have no control over only one output being on at a time.

 

How are you generating and triggering the audio? What media are you using to store the audio?
I ask this because this is an ideal application for a small embedded computer - Raspberry Pi or similar. Perhaps with an external I/O unit for buttons and lights.

 

How are you generating and triggering the audio? What media are you using to store the audio?
I ask this because this is an ideal application for a small embedded computer - Raspberry Pi or similar. Perhaps with an external I/O unit for buttons and lights.

The audio will be triggered and played back on a small audio module that plays back stored files depending on which pin goes low. I have thought about trying a Raspberry Pi to serve as my controller, I would just have to study the code. I'd need something that basically said, if this relay is on, turn off all others for each one. My only concern is this would be depending on the computer to run and if there was an error, the message and light wouldn't fire. I'd need a light/buzzer to indicate if the Pi was offline I would imagine.

 

My issue is that I need the relays to latch on with the button, but I also need to make sure that only one is on at a time. For example, the push button panel will have 3 buttons, and each of those buttons will be a different priority. In case the wrong button was pressed, or the priority level changes, I only need one output on at a time.

I think what you are after is typically found under a heading of "Game Show Circuits". One of three buttons is pressed and the first button pressed will lock out the remaining two. Circuits like this are pretty simple and generally use an SCR. Here is a single example, obviously you would modify the circuit but the centerpiece is the use of an SCR. Take note of this: The control devices may be just about any non-sensitive gate SCRs or triacs with a current rating of a few amps. You want a non-sensitive gate SCR. A Google of terms like "Button Game Circuits" should get more ideas for you.

Ron

 

I think what you are after is typically found under a heading of "Game Show Circuits". One of three buttons is pressed and the first button pressed will lock out the remaining two. Circuits like this are pretty simple and generally use an SCR. Here is a single example, obviously you would modify the circuit but the centerpiece is the use of an SCR. Take note of this: The control devices may be just about any non-sensitive gate SCRs or triacs with a current rating of a few amps. You want a non-sensitive gate SCR. A Google of terms like "Button Game Circuits" should get more ideas for you.

Ron

Much like this, yes. But more so that it doesn't lock the other relays and allows for another button press to change the active relay while deactivating the prior one.

 

Would a "radio push-button" circuit such as this do what you want?

 

Would a "radio push-button" circuit such as this do what you want?

Yes. Thanks!