finally tested our MTH 0-6-0 ($120 for a sound model!) ... And it is getting stuck on 100% of the turnouts. Need a capacitor ...
anyone done this specific unit? General capacitor advice?
it's a bit more than just a capacitor
a typical capacitor is too small (or requires a large space), so supercaps are used.
such a large capacitor will draw a large amount of current when power is turned on, making it look like a short. This "inrush" current must be limited, hence there is a resistor and diode in series with the cap.
with a dcc decoder, the "keep alive" is between the bridge rectifier and the decoder supply input. The resistor limits the current into the capacitor from the bridge (i.e. rails) but the diode allow unimpeded flow from the capacitor into the decode (the bridge diodes block current from from the capacitor out to the rails).
greg - Philadelphia & Reading / Reading
In case you are not aware of stay alive, just connect the two wires from the stay alive module to the plus and minus operating voltage on the decoder.
The below link might help in identifying the way to connect.
http://www.members.optusnet.com.au/mainnorth/alive.htm
Different decoder companies will have a different name for the super cap module. Much, much better than using just an electrolytic cap.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.