PSX1-AC

Really helpful, thank you Gary.

@Windy City - If you do a search for "PSX 1AC" you'll get several topics that mention or discuss the PSX-1AC including how to wire it into your set-up.

A

There's always the instruction sheet...

PSX-AC Manual (PDF)

You really need them for each output of the post war ZW. The ZW-L probably has a fast electronic breaker. Your call there. But the neat thing is that you can set the PSX-1AC units for whatever amount of amps you want the trip.

Sometimes it helps if you do a quick overview of your power setup so the great folks on this forum can better help you.

- Are you conventional only?

- Do you plan to use a command control system?  Legacy, DCS, or both?

- How much power are you putting to the track?  If over 10amps (one PH180 or one channel of the ZW-L) there are additional considerations to think about.

That second question is important because the PSX is known to degrade the DCS signal somewhat so to keep your DCS signal strong you need an additional choke installed.

I have no idea how fast the breakers are on the ZW-L.  If they are as fast as the PH180 that would be great, but the PSX is faster.

The PSX1-AC is also really only for command use, it won't pass low voltages.  From the TIPS section of their site.

The onboard processors derive their power from the input power to the PSX units. To prevent any unpredictable
operation the input voltage should be kept above 10 volts.

@gunrunnerjohn - I take it you can't use J1 to supply an external power source in addition to the AC source?  I'm really surprised you can't feed that board your own DC source.  I'll have to buy one to start poking at it. A

I haven't tried an external supply, but all my reading on the PSX-AC suggests it's really designed for command use.  They started out with a similar design for DCC use.

@gunrunnerjohn posted:

I haven't tried an external supply, but all my reading on the PSX-AC suggests it's really designed for command use.  They started out with a similar design for DCC use.

It looks like to me that half of that board is devoted to rendering a DC supply from the power source.  Also, I would have used a potentiometer to select the overcurrent protection but that would be problematic for some users. A

I appreciate the technical discussion but would like to get back to my original and basic questions: theses issues were not addressed in the instruction manual

Do I need a PSX1-AC with the ZW-L? I was going to use it for my PW-ZW.  Do you recommend it for both?

Can someone share a schematic of how they place and wire the PSX1-AC and TVS, relative to the transformer?

What version of the PSX1-AC is recommended?  Optional LED vs Buzzer?

I have put together 4 "transformers" using the PSX-AC with PowerMasters.  Two use a 360 PM with the PSX set at 15.4 amps, and two use the 180 PM with the PSX set at 8.0 amps.  I also use the TIU passive mode circuit that was (is?) sold by forum member Zachariah Hubl.  The input board has a 22uH choke built in to mitigate the DCS signal interference.

@CAPPilot posted:

Sometimes it helps if you do a quick overview of your power setup so the great folks on this forum can better help you.

- Are you conventional only?

No, mainly TMCC

- Do you plan to use a command control system?  Legacy, DCS, or both?

Legacy not DCS

- How much power are you putting to the track?  If over 10amps (one PH180 or one channel of the ZW-L) there are additional considerations to think about.

I was planning on using a ZW-L, one handle for each of the 4 loops, and a PW-ZW for 2 additional loops, and another PW-ZW for accessories

That second question is important because the PSX is known to degrade the DCS signal somewhat so to keep your DCS signal strong you need an additional choke installed.

Not an issue for me if I use TMCC?

I have no idea how fast the breakers are on the ZW-L.  If they are as fast as the PH180 that would be great, but the PSX is faster.

Can you share a schematic of how youplace and wire the PSX1-AC and TVS, relative to the ZW?

@Windy City posted:

I appreciate the technical discussion but would like to get back to my original and basic questions: theses issues were not addressed in the instruction manual

Do I need a PSX1-AC with the ZW-L? I was going to use it for my PW-ZW.  Do you recommend it for both?

Can someone share a schematic of how they place and wire the PSX1-AC and TVS, relative to the transformer?

What version of the PSX1-AC is recommended?  Optional LED vs Buzzer?

ADDED:  I see you have already answered the questions.

I would use the PSX with both the ZW-L and PW ZW.

I think there is only one version of the PSX-AC.  The others, like PSX-1, are for DC.  I get these from Charles Ro.

The optional LEDs and buzzer just make it easier to know there is a problem.  The PSX will keep trying to reset until the short is cleared, and power will be back on as soon as the short is cleared.  Because of this, as a minimum I would add the reset switch shown in Gary's video to J7 pins 2 and 3.  This way you have control over when power is again applied to the track.

You have not said what your setup is.  Here it is with the TIU in line with track power.  No TIU?  Disregard the TIU and choke in the diagram.

Here is one way to do it with the TIU in passive mode.  Again, no TIU just disregard it and the choke.

@gunrunnerjohn posted:

The PSX1-AC is also really only for command use, it won't pass low voltages.  From the TIPS section of their site.

The onboard processors derive their power from the input power to the PSX units. To prevent any unpredictable
operation the input voltage should be kept above 10 volts.

They should really have these powered by a wallwart instead of track power.  Been meaning to look into this and come up with a mod for these.  Power the device externally and be able to use it in a conventional world.

@superwarp1 - I couldn't agree more to the point I started specking out my own over current protection device.  Something came up immediately in the design...spike current verses over current.  Given the comments about how quickly these units trigger, I suspect they catch spike current.  The issue I  see is that, when starting up a consist of 3 or 4 engines on Atlas track in particular, there will be an inevitable momentary current rush and voltage drop.  I've been debating on whether to design for both of these situations, where the spike current threshold would be offset from the over current threshold.  Just a thought.

Anthony

Anthony, have you looked at the Lionel Powerhouse 180 circuit protection?  It has exactly what you mention, overcurrent and spike current protection.

In the schematic, both U1b and U1c are amplifying the current sense signal.  U1c, the "overload" detector, has a gain of 148, but it is slowed down by the resistor and capacitor on its output.  The time constant (RxC) is 2.6 seconds.  Multiple short hits to this RC combination would charge it up until it trips the relay latch.

U1b has a gain of 37, which means it requires 4 times as much current, but it acts instantaneously for "dead short" situations.

@gunrunnerjohn - I had no idea that the schematic for the PH 180 was even available from the ether.

It might be helpful to list some of my goals and commentary on the matter:

* Instead of using a wire wound transformer (L1), I was going to use a current sense device.  This way there will be absolutely no current draw from the power supply.  However, this method is inherently prone to electric disturbances and anomalies.  So it may not be feasible to do so.

* I would like to be able to transmit the RMS voltage and RMS current to my layout controller.

* If I have the RMS current at my disposable, I can use that signal for the over current protection.

* I also want to be able to set the trip points (no jumpers!).  Not that the PH 180 schematic can't be easily modified to support this.

* I noticed that the value for C4 is not given.  The value of this capacitor is fairly critical.  My guess it's 0.1uF.

* I once worked for a gentlemen with a Masters in Electrical Engineering who couldn't understand the purpose of D2.

* It seems Lionel uses 8V as the default for just about everything it makes with electronics.

Anthony

@superwarp1 posted:

They should really have these powered by a wallwart instead of track power.  Been meaning to look into this and come up with a mod for these.  Power the device externally and be able to use it in a conventional world.

I would be very interested in this.