Skip to main content

Replies sorted oldest to newest

Bill I am using a cab 1 base to run my asc's and my bpc's and tpc's. I did hook up up the cable that came with my legacy set as per the Lionel video, however my cab 2 has no effect on operating these, but my cab-1 will still function and run all of them. I made my own cable to connect my cab-1 base to my controllers. I would assume the cable pin-out is still the same. If so should not the legacy base operate these or am I missing something in programming my cab-2. Hope this helps. chief
Dale if you mean controllers suchas asc's etc. I have 2-tpcs 10-ascs 6-bpcs. My old cab-1 base runs everything just fine however when I plug the cable from my old base into my legacy base nothing will respond. I can however load and run tmcc engines just fine. My cable is a home made one so maybe the db-9 female connector does not extend into the base enough. Not sure I could get a new base cable and hook up one controller and see how that works. Any ideas appreciated. chief
The cab1 base had a transistor that pulled the output up to 5 vdc, I think more capable of being loaded than the cab2. I found that with just about a 500 ohm load, I pulled the output of the cab2 down from approx 8vdc to about 3 1/2 vdc and it would no longer drive a single TPC. FWIW, a load of about 1K ohms lowered the output to about 5 vdc and the TPC responded ok. I would not be surprised to see a buffer amp product on the market for the bigger layouts using the cab2.
quote:
Originally posted by Dale Manquen:
quote:
that's RS-232, right?


Not reallly. It is "RS-232-like", operating within the narrower voltage swing of zero to five volts, and sourcing substantial current.


Looking at the CAB2, the output is +/-8v. So I wonder if there is some future reason for the RS232 rather than the "RS232-like" which is what the CAB1 used. I take it, as per your parts list, the 3904 pulls the base of the 3906 lowish and the output goes to +5 v...like the output of the CAB1.
quote:
Originally posted by cjack:
quote:
Originally posted by Dale Manquen:
quote:
that's RS-232, right?


Not reallly. It is "RS-232-like", operating within the narrower voltage swing of zero to five volts, and sourcing substantial current.


Looking at the CAB2, the output is +/-8v. So I wonder if there is some future reason for the RS232 rather than the "RS232-like" which is what the CAB1 used. I take it, as per your parts list, the 3904 pulls the base of the 3906 lowish and the output goes to +5 v...like the output of the CAB1.


Also, the 2N3904 emitter-base breaks down at 6 v. Is a diode necessary there (after the 10K resistor input) because of the -8v from the CAB2?
quote:
Looking at the CAB2, the output is +/-8v. So I wonder if there is some future reason for the RS232 rather than the "RS232-like" which is what the CAB1 used. I take it, as per your parts list, the 3904 pulls the base of the 3906 lowish and the output goes to +5 v...like the output of the CAB1.


Also, the emitter-base breaks down at 6 v. Is a diode necessary there (after the 10K resistor input) because of the -8v from the CAB2?


You have the concept:
A 10K resistor to current limit the input from Pin 2 to the base of the NPN 2N3904. A 1N4148 might be a good idea here, too, as you suggested. Connect the diode across the base and emitter terminals, with the cathode (band) end attached to the transistor's base.
A 10K resistor from the collector of the 2N3904 to +5V to provide cutoff for the 2N3906.
A 10K resistor from the collector of the 2N3904 to the base of the 2N3906.
A 1K resistor from the collector of the 2N3906 to ground.
Connect the output Pin 2 to the collector of the 2N3906.
The 2N3904's emitter is tied to ground, and the 2N3906's emitter is tied to +5V.

I would probably build this in a plastic pill bottle.

If you want a built and tested unit, send $25 to me. If you want a kit with instructions, send $15. These prices include shipping.
The TMCC Command Base does not have a negative voltage source available, and since the Lionel controllers are all operated by turning on an optocoupler, there was really no need to add the cost and complexity of a negative supply.

The input to the TMCC Command Base has a shunt diode across the base of the input 2N3904 to deal with the negative polarity of RS-232. The 10K resistor limits currents for both directions. I will amend my previous post to use that method.
First off Dale you guys are way over my head now. I did talk to Lionel today and as you stated previously the cab-2 base will only drive 4 outputs. So I asked the the tech if that is true, what good is a cab-2 that can do 99 switches and 99 routes. my old cab-1 now runs several controllers as it is. I really do not understand Lionels thinking on this one. Perhaps santa fe fan can enlighten us or add something to this discussion. chief
Your old cab1 has an output like the booster Dale is suggesting. The new cab2 has a less capable output as far as driving other dat inputs. I think it has an RS232 chip like the MAX232 which has an output impedance of about 300 ohms. What this means is that the cab2's output will be at half voltage when asked to drive an input load of about 300 ohms. So...that would be realized when you try to drive say 6 dat inputs of about 2000 ohms each. So 4 inputs would be a safe limit.
This has nothing to do with how many switches you can operate with the RF output. Its a different output...not the dat output from the db9 connector. I think you know this of course...but with so much capability, it is odd that the dat output on the cab2 is so limited.
From Lionel's view, I guess, if they make something that requires driving more dat inputs, they will provide dat pass thru with booster. In the case of driving 99 switches, they do it with RF with SC-2s or the new Command switches. But they can't provide for every other manufacturer's device as I found out trying to drive a DZ2001 with about a 400 ohm input resistance. In that case it is necessary for the aftermarket device manufacturer to provide a lighter load or a booster.
I find this discussion both interesting but also a bit confusing. At one point I did have the Legacy system set up on my layout and frankly did not have any major issue with operations until the Legacy unit and then the CAB2's failed several times and had to either be upgraded or replaced.

While I was using the Legacy system I operated two TPC 300's, 1 ARC, 1 ASC, 1 AMC,1 BPC along with 1 Z-Stuff Data Wire driver without any issues. So, I was addressing 6 products not 4.

I have since gone back to the CAB-1 not because of any operational issues but rather a concern that the CAB-2 system is a work in progress and is safely put away in it's box until all the various issues are resolved.

One thing I can say is that unlike the CAB2 system the original TMCC CAB1 system is relatively bullet proof.
The Z data driver surprises me a little...I couldn't get the one I had to be used with only one TPC.
But otherwise there may be enough variation in devices to explain your results.
Anyway, I think Dale's solution (and offer) is the solution. I don't see Lionel solving this at least in the near future or at all. Not anything negative about Lionel, they just don't seem to be in a position to support more than four of THEIR devices at this time. Dale's circuit is exactly the output of the "bulletproof" cab1 and will end the issue for those needing dat power to run multiple devices.
quote:
The Z data driver surprises me a little...I couldn't get the one I had to be used with only one TPC.


This is the older version that I first used with my CAB1 system. It does not have the LED that some of the newer ones have.

Also when I connected the Legacy system up to my layout I did not keep the CAB1 system connected. Only the Legacy system was connected to the various components.
What we are posting about is strictly a hardware issue. Nothing to do with the software or the data content. It's just that the hardware data driver in the CAB2 is not capable of supplying enough current to do more than four devices. The solution is as Dale suggested, a couple of transistors in a little package with a female db9 connector in, a male db9 connector out, and a +5vdc wall wart to supply power to the little package.
Does it make any difference if some of the devices are programmed as engines?

I know TPC's can be programmed as engines what about some of the other devices?

If they were programmed as engines would it resolve the issue of only being able to operate 4 devices?

You could program all your TPC's to the same engine number and when addressed they would all turn on at the same time.
Post
×
×
×
×
Link copied to your clipboard.
×
×