View single post by man7sell
 Posted: Thu Apr 25th, 2019 07:00 pm
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Joined: Tue Dec 21st, 2010
Location: Snohomish, Washington USA
Posts: 420
The age old problem, of small locos loosing power, over turnouts and dirty track.

Can't afford to go buy that many commercial circuits,
for 3 Porters, 2 mechanicals, and whatever will come in the future.

So here goes ...

First the circuit :   :brill:

The basis for holding the charge will be five 1 Farad super-capacitors.
Rated at 2.7 Volts each, in series, will hold a total of ... 13.5 Volts.  

You could use six, for a total of 16.2 Volts.
Or use 3 Volt rated super-capacitors, five in series would be 15 Volts.

To protect the super-capacitors from over voltage,
a 15 Volt Zener-diode is used in parallel with the super-capacitors.

Also a 3.3K Ohm resistor to control discharge, when the loco is removed from the power,
again in parallel with the super-capacitors.

A regular 1N4001 diode, bypasses the 68 Ohm inrush limiting/charging resistor,
for discharge to the decoder, on the blue common positive wire.

Lastly to address programming the decoder,
the keep alive-circuit needs to be either disconnected (connector or inline switch),
or a 100uH 0.5 Amp choke in the negative side of the circuit.

All of this will be installed in a tender.

Photos of the build to come.

Rail Systems Built Inch by Inch
Capt. Paul Mansell
m (-_-) m
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