CAPPilot posted:Okay, how this this revelation on voltage impact affect my power setup? I'm running passive mode on my two mainlines to get more than 10 amps to the track. I use a 34A 22uH choke. Here is my setup:
The PSX-AC is set at 15.8 amps because that is all I need for the passenger train I plan to run (about 11-12 amps).
I did a less technical test of this setup on the affect on the DCS signal only. Without either the PSX or choke, the signal strength was 8. With the PSX but without the choke the signal strength dropped to 5. Adding in the choke with the PSX the signal strength increased to 9. Used two different engines.
So, the way I read Dr. Tang's scope readouts adding the choke does two things for me: 1) increases voltage to the track, and 2) increases DCS signal. Is that correct?
NOTE: John and the rest of you anti-more than 10 amps folks, I have no plans to go to power districts
Hi there,
You're right the DCS signal should increase with the choke becasue it the PSX won't load the output of the TIU.
The choke works by frequency selectively providing an impedance to to the TIU output port that allows AC 60 Hz to pass but not the DCS signal.
A 22 uH choke is going to provide an impedance of Zchk=j X (freq) X 2pi X L
L = 22e-6 Freq = 60 pi = 3.14159...
At 60 Hz power this is about 0.5 ohms. Which means the power signal can go right through it without much issue as it's basically a short.
The DCS signal is at about 3.7 MHz
the impedance is Zchk=j X (freq) X 2pi X L
L = 22e-6 Freq = 3.7e6 pi = 3.14159...
At 3.7 MHz the impedance is 30.6K...basically like an open circuit.. so it won't affect the DCS at all.
Since the 60Hz behavior is basically a short, its unlikely the choke can increase the track voltage... only the DCS signal. Also I don't know how we all arrived at 22uH... any high value.. like 10-500uH will work as long as it can handle the current. Don't go too high though or the series resistance will become a problem...
