i recently bought a newer n scale bachman engine for my n scale layout. this engine has a capacitor with one leg atatched to the negative and one to the positive. this engine never stalls and the lights never flicker. i have 3 older engines that i believe are also bachman and would like the same results. where can i get these capacitors. i do not run dcc. thanks for all your help in the past.
Those capacitor are strictly for RF interference supression, they do nothing to act as a keep alive, which wouldn;t work with DC anyway. Your newer model likely has better or just cleaner pickups and wheels compared to the old ones, which is why it runs better.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Considering the size of the capacitor and the low voltage of the system, the probability of keeping the motor running across, for example, a dead section of rail one millimeter longer than the pickup wheelbase is a very close approximation of zero. The low voltage is the killer. In applications where capacitors show serious storage capability, either the capacitor is huge or the charging voltage has kilo or mega for a prefix. In the case of some of the hardware used for subatomic particle accelerators, the answer is both of the above.
A friend and I once calculated how much capacitative storage he would need to keep his HO diesel switcher moving if his puzzle palace terminal throat wasn't powered. The answer was, load the entire train with the best commercially available capacitors and it MIGHT run four feet - maybe. Just to get it to run the length of a #8 turnout closure rail would have been a boxcar load. Modern motors draw less current and modern capacitors are better - but not that much better.
Chuck (Modeling Central Japan in September, 1964)
It might be interesting to redo the calculation using the latest supercapacitors, a trainload of those should keep a modern loco moving for a long time. And then where is the trade-off, as the train gets longer you have more stored power but it also gets heavier so you need more power to run it.
It seems to me that if you could just get 1/2 or 3/4 of an inch in N scale this would be enough to keep most any loco running through dead frogs, or similar situations . What kind of a capacitor would the electronics experts recommend to do this???.....Mike
tomikawaTT Considering the size of the capacitor and the low voltage of the system, the probability of keeping the motor running across
Considering the size of the capacitor and the low voltage of the system, the probability of keeping the motor running across
LION is not so sure about this, but then LIONS are unsure of many things.
A regulated power supply is filled with capacitors, and if you turn it down to zero the train can keep going until the capacitors fully discharge. But then, something else may be at play here, and the capacitor is only driving a little transistor that is supplying current to the tracks. Still, that circuit does not take up much space inside of the power supply. One should be able to transplant it to the locomotive.
LION *is* interested in using Super Capacitors in working the lighting on his subway cars. The geese do not like to be left in the dark just because the train is stopped. All Electronics did have some 12 volt 1 Farad Capacitors, but alas no more, so the lion is using several 0.33 Farad caps to see what they will do. LION can always add more capacitors to the circuit until it behaves according to specification.
I will see what happens when I institute plan "E"
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
If the capacitor is charged to max track voltage say 12 volts then in 1 (one) time constant it will dischage 63% to 4.45 volts.Time constant is defined as TC ( in seconds ) = Cap ( in farads ) X Res ( in ohms ).
Note: Cap is FARAD and not uF - microfarad. As stated before you need a whole train load of Capacitors to move a short distance.
Problem is, with DC, going slow, you have maybe 5 volts on the track. And goign slow is precisely when you need the help the most, if the loco has a flywheel then at speed it can coast past small interruptions. It's all a question of energy density. With DCC you have full power at all times to fully charge the capacitor then dole it out when needed.
I have some with the single cap attached to the decoder which is for stay alive.
Caps used for RF interference are a lot different and are on a PC board or attached to the motor leads. I have both.
Some here need to do research about how caps are used in Bachmann locos, EU requirement, and with decoders.
Below is a link about stay alive caps. How to add more cap. He has actual examples, not opinions.You better know what you are doing before messing with this.
http://www.members.optusnet.com.au/mainnorth/alive.htm
Super caps are not for 12 vdc.
Most memory caps, sometimes called super caps, are 5.5 to 8 vdc as they are used to backup 5 volt logic circuits.
Many use these caps in LED lighting circuits which is low voltage.
I have a flashlight in my car that uses super caps with super bright LED's and uses a hand crank to charge it up. Six months later, the flash light still works and one or two cranks for full light.
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.
Again, that's for DCC< it won;t work with DC, and the OP stated he is runnign DC.