Circuit Protection for Toy Trains - page 1
All power feeds from toy train transformers must have circuit protection in the line. Use the lowest value protection that will hold the circuit closed. Track for passenger cars will require the highest value protection. Transformer internal breakers protect transformers, not trains.
Polyswitches and Breakers
A 3A Panel Mount Circuit Breaker
similar to the one shown above would be part #W28-XQ1A-3 by TE
Connectivity. The button extends for visual trip
indication.
POLYSWITCHES Raychem Circuit Protection Polyswitches devices are commonly called resettable devices to distinguish them from traditional one-shot fuses that work only once and then must be replaced - an expensive and inconvenient proposition. While the generic term for these devices is sometimes called "PTC Resettable Fuses", technically these are not fuses but actually non-linear thermistors. PolySwitch devices are the world's leading PPTC (polymeric positive temperature coefficient) devices for circuit protection in a broad variety of electronic equipment applications.
PolySwitch is made by Raychem which is a division of TYCO Electronics.
Decide
What Size Polyswitch
Use RUE or RXE series - Always use the smallest one possible.
Under Current Rating, use Hold Current of 9A if you’re running
two long passenger trains or two postwar trains - Mouser
#650-RUEF900
One modern freight train would use 650-RXEF375
Two of my operating accessory circuits have been raised from 3A
(650-RUEF300) to 4A (650-RUEF400) .
With several people operating different accessories at once I
had to up the rating.
For my Z-stuff switch machines circuit, I use 2 1/2 A
650-RUEF250.
| Terminal strips afford the best wire connections. Solder terminals together for common connections. |
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Polyswitches and Panel Mount Breakers are interchangeable.