How does a Simplex 4208 work?

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Casual Participant
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Joined: Wed Sep 17, 2014 9:59 pm

This is a question probably for Retired STR-SG but anyone with knowledge can chime in,
Since the Simplex 4208 has been retired long long ago, and with my research saying it's a relay based panel, I could probably build myself my own 4208 ish panel using basic electrical components. Here are my questions,

1. How were the 4208 zones wired up and how does it activate the NACs without a microchip relay?

2. What is the difference between an AC output panel and a DC output panel? In modern day conventional panels 24vdc are sent over the IDC's, is it the same with the 4208? 120vac over the IDC's with an AC panel or 120vdc with a DC Panel? I know AC alarms were wired in series. For example if there are 40 Simplex 4050s in the building, each 12 volts each, it would need 480vac over the NAC to power all the horns. If the system takes 120vac input power, would you need several capacitors to step it up to 480vac or is there several other power cabinets that do that? Same thing with 2 horns, would you need several resistors to bring it down to 24vac? Does the same apply to DC panels and were DC horns wired in series as well or in parallel like today?

3. If you have schematic of a 4208 panel or any pictures that clearly show the circuit board that would be terrific!

I own several AC horns and would love to have a vintage alarm setup instead of my current situation of AC horns connected to a 4251-20 which is acting like a light switch.
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