Help building a relay based AC fire alarm panel

I am willing to take on the endeavor of building a 1970s relay based AC powered fire alarm panel. Since I found out it used just standard relays, which are still made today, and how uncomplicated these circuits are, I figured why not? However, since there is little documentation on these older panels, I’m still a little unclear of how the zone relays, alarm, and horn relays would actually work together? NewAgeServer did this with his Alertek 5001-DC panel, except mine would be AC. Can someone point me in this direction or knows some documentation or video that explains all this? Also I wanted my horn circuits to be the Simplex 2001 style march time. I wanted to build a code wheel using a synchronous motor but I don’t know how complicated finding parts would be?
Otherwise maybe a programmable timer? The system would use a potentiometer to control AC voltage per horn circuit, as AC horns were wired in series.

Also does anyone know where I can order a cabinet and colored incandescent lights, as that’s what they used back then?

Thanks for any help you can provide!

You might try eBay, I’ve seen AC fire control panels and parts for them float up from time to time. A lot of the sellers seem to not know what exactly it is that they’re selling (if they are renovating a building or something), so that means that 1. you need to try a lot of different search terms since they might list it without a brand or with a random part number written on the item and 2. you’ll likely get it for far less than what you would pay from a professional seller.
Disclaimer: 120VAC is incredibly dangerous and you should definitely plan this out carefully and test it with low voltage DC if possible before plugging anything into wall power.

If you want to build a panel that supplies AC to the horns on a supervised series circuit, here’s my recommendation: use an Arduino (Uno/Mega) or similar for a microcontroller. Use a set of digital input pins on the controller to monitor a dry-contact input (like a pull station or fire alarm relay from another panel) to trip your panel.
Use 2 sets of relays to connect your NACs directly to the Arduino during supervision, and have the controller simply use DC to check for continuity between the 2 wires. Since the transformers in AC horns simply short a DC signal, if you apply +5VDC at the beginning of the loop, you’ll read +5VDC at the end of it as well - if the wiring is complete. When your panel goes into alarm, switch off the relays connecting your controller to the NAC, and switch on a different set of relays to connect your NAC to AC. Definitely include a fuse or circuit breaker on the AC line in case something goes wrong. Also, the supervision and AC relays should be connected in such a way that turning either set on will automatically switch the other set off, since exposing any type of logic circuit to AC power will kill it. Use the microcontroller to switch the AC relays on and off in a pattern, and you can code the horns this way. I can try to help you get a circuit diagram together, I have taken on similar tasks myself, however I am not and would never claim to be a professional.

If you have a diagram that would be cool. I’m trying though to go old school, relay based logic. Since it uses AC horns, there is no reverse polarity, thus no supervision unless you send a small enough voltage or current, but that’ll still make the horns buzz a little, like an the underpowered 4050 on NewEnglandElevators channel.
I’m not worried about NAC supervision. However this panel would mimic an AC 4208 panel. I forgot you can use a transformer to step down the voltage to 24vac for the zone latching circuit. The 120v to the horn circuit would have a petentiometer to divide the voltage to the amount needed on the horn circuit. For example, if you have a 7004t-115 on the circuit, you then have the petentiometer not resist any voltage and the full 120v would go to the 7004t on an alarm condition. Now if you have six 4050 horns on one circuit, 12 volts each, you would have the petentiometer resistance set to divide the voltage to around 70-75 volts. You can check with a volt meter. That’s how the old panels work, horns were wired in series and that’s what I’m aiming for.

PM sent to jm2014.