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Discussion Starter · #1 ·
The local train club has 8 separate loops powered by 4 MTH Z4000 transformers with 4 of the mainline tracks connected passively to a TIU. We wanted to upgrade from the cheap thermal circuit breakers we have been using to PSX-AC breakers but also wanted to help operators who may be trying to watch several tracks and multiple transformer handles, so by using audible MP3 announcements coupled with remote LEDs near each handle the user can both visually and audibly correct a shorted or derailed train while still leaving other tracks operational.

Since we wanted to run passive mode (not run power through the TIU) we needed external 22uH inductors on each channel at the transformer. I decided to add them to the PSX-AC boards directly by cutting the main trace on the output and surface mount soldering the large inductors to the board. Since we will not be using the piezo sounder option, we can use that space on the PCB.
An unmodified PSX-AC
Circuit component Passive circuit component Green Hardware programmer Microcontroller

First I cut the trace. I used a sharp pair of side cutters placing one tip at the edge of the trace, and the other near the middle and while pressing hard into the PCB squeeze the cutter tips together cleaning cutting the trace. Then I scrape away the green solder mask for pads to mount the inductor to.
Passive circuit component Circuit component Hardware programmer Electronic engineering Electronic component

last, I solder in the inductor
Passive circuit component Circuit component Green Hardware programmer Electronic component


I also need to work on a plan for the aux power to ensure the PSX-AC logic section is powered even when the input is not seeing power in. This is easy as they are just using a diode and 1000uF 25V cap to then regulate using a 5V regulator for logic power. The plan is just move a resistor to no longer depend on the input power to feed the system.
I'll then use the opto-isolated output to trigger the MP3 player module.
Font Parallel Diagram Plan Number
 

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Discussion Starter · #2 ·
So then here is the MP3 module that will get connected.
This was the module I'm using https://www.amazon.com/gp/product/B07YFPBGF8
A good datasheet and manual https://grobotronics.com/images/com...ce Playback ModuleDatasheet.pdf?1559812879320

The other trick was, I found an online text to speech website that lets you save in MP3 format.
 

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Discussion Starter · #3 ·
I'll be posting more on the complete end to end wiring of the project as I do more testing and modifications.
 
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