I am looking to design a voice evacuation panel that can broadcast up to three messages, Fire, Severe Weather, and All Clear situations. Additionally, I would like to incorporate a built-in microphone to facilitate live paging. how could I build this?
The first part could be accomplished with the MP3 board a handful of enthusiasts use: simply hook either a toggle switch or a button to each input & configure the board accordingly (tell it to repeat each message indefinitely until the input opens for toggle switches & tell it to play them once when the inputs are closed for buttons). As for the second part, I came up with a potential plan for adding microphone functionality to an existing MP3 board setup, but it requires the use of an actual voice panel’s amplifier, which is hard to find & thus means I haven’t actually tested it to see if it would work.
Does it have to be a voice evac panel amplifier, or can I use a regular one I have lying around?
The plan I figured out requires a very specific brand & model of amplifier that like I said is very hard to find (there was one on Ebay once but it’s long since sold).
oh, can I still here the plan, I am very curious.
Sure, let me see if I can recall it. It’s based off a concept first tried by Youtuber “espiforenque”, now known as “Nick’s Mad Science!”: he had purchased an Audiosone AU-360-E amplifier intending to use it with his Wheelock VoiceLink DV-200 voice panel, only to discover that the latter didn’t work. He then thought to take a Raspberry Pi & connect it to the amplifier: when the system was activated the amplifier would play a tone & the Raspberry Pi would then interrupt said tone after a few seconds & play a message, after which it would allow the amplifier to continue playing its tone, & the cycle would repeat. It worked but the message was very quiet.
My concept is sort of the opposite of that: the MP3 board that several enthusiasts use (in my case the 20-channel one that I use since it has more inputs which equals more messages) has its audio output terminals connected to the AU-360-EM’s audio input terminals (The AU-360-EM is the same thing as the AU-360-E, but with an included microphone), with the amplifier’s audio output terminals then being connected to whatever speakers are in the system. The amplifier is never tripped by the panel so it doesn’t play its own tone, but the MP3 board plays both a tone & a message over the speakers through the amplifier when it’s tripped (either through a connection to the main FACP or by an external switch), via a relay on the MP3 board closing the circuit on the amp’s “press to talk” terminals. The amplifier’s only real purpose in the setup is to enable microphone functionality as it has one connected as standard: like I said I have not tested this setup to see if it would work but my theory is that the microphone would override the audio input terminals & allow you to talk over the speakers with it (though there’d then be the problem of the MP3 board continuing to play its tone & message while the microphone is keyed, thus potentially cutting off part of either). Obviously of course the amplifier would still need power even if it would never actually be tripped by the FACP.