New Switch Question

[lionelsoni]

There is some difference between AC and DC operation, in that the impedance of the coil is higher for AC. Impedance is the combination of resistance and reactance which determines how much current flows for a given voltage. These two components of impedance add as the square-root of the sum of their squares. The resistance is the same for AC and DC; but there is no reactance at DC. So a coil will generally draw more current on DC than AC, at the same voltage.

[fwright]

To answer Dale Hz's question, switch machine coils don't care whether power is AC or DC. The current creates a magnetic field which attracts an iron slug or cylinder that is attached to the throw linkage. Reversal of the magnetic field with AC is of no importance because the slug is equally attracted to either magnetic pole, and possesses almost no residual magnetism of its own. Same principles apply to the uncoupling/operating magnets.

The important feature of a capacitive discharge (CD) system for twin coil switch machines is that it prevents the burning of the coil that occurs if a button is held down too long or sticks in the on position. The CD system delivers a very short pulse of energy to the coil, usually 18-24 volts. This causes the machine to have "snappier" action. But the limited duration of the pulse prevents the coil from over-heating. CD systems are highly recommended for Atlas switch machines which are known for overheating (in all scales) when the button gets stuck or the switch throws slowly.

yours in switching
Fred Wright

[Anonymous]

To answer Roger's question, Atlas does sell their own #200 Snap Relay for $8.55. Tim...Maybe "The Complete Atlas Wiring Book" has tips on designing the type of automatic train control system you desire.

Bruce Webster

[Anonymous]

Another practice to throw Atlas switch machines is with a capacitor circuit.This is easy to make,the only question I have is coil life on the switch machine since they are AC coils.

Dale Hz

[Anonymous]

I use insulating pins and run the track power through one contact set of a DPDT center off automotive switch I purchased at Radio Shack. The switch will direct power to either one spur or the other but not both at once. I use the second set of switch contacts to throw the switch machines through an interval timer set at 1 second. This avoids switch machine burnout. Resting the toggle switch in the middle for a brief moment allows for the timer to reset.

Dale Hz

[Anonymous]

Thanks, the DZ switch machine may be what I'm looking for. The rest of my layout is Atlas track and I like their switch, with the exception of the power issue.

[Roger Bielen]

Tim - to accompli***his you would need to have an insulating pin/gap on the center rail from the switch and an auxilliary set of contacts on the switch motor to shut off the power to the isolated track. The DZ switch machines from Z-Stuff have a relay add on available that will do exactly what you want. I don't know if Atlas has an available relay for the switch machines they use.

[Anonymous]

I now understand why my Atlas switch lets power go on to the spur that i was hoping would not have power. I also understand that my older Lionel switches (which I don't like) shut off power to the spur. My question is as follows: who makes good quality switches that will shut off power to the non active spur?

Thanks,

tim