Large Scale Central

Signals on the NVRY

Electronics
#21

@Michael: The tubing is 3/8" OD. I’ll be using custom software running on a PC, and using PCI-DIO-96 data acquisition cards from National Instruments.

@Jon: I’m experimenting with circuits using the TDA0161 chip. The chip is a proximity detector chip used mainly for control systems, but with a bit of extra hardware and some coils, they apparently become a pretty good metal detector. Adding a rare-earth magnets to ‘tickle’ the detection loop gives it a great range. Price per block is going to be about $2.

#22

Thanks for the info on the system. I’m planning mine on an Arduino. The mega can cover, according to my sketch, around 15 blocks with lights in either direction.

The code is written for a four-block loop, and testing starts shortly. Planning to use optical sensors, because I do not want to release the block till the train is OUT of the block! But it’s all software and theory till I light up a few LEDs!

The arduino can be controlled by a remote link, to go from dispatched to autonomous.

#23

Yep, an Arduino Mega has a good price/bit. Id probably be using Bruce Chubb’s SMINI cards if I didnt already have these NI cards.

Today’s project is turning several computer power supplies into 5v/12v supplies for the RR.

#24
Bob McCown said:
Yep, an Arduino Mega has a good price/bit. Id probably be using Bruce Chubb's SMINI cards if I didnt already have these NI cards.

Today’s project is turning several computer power supplies into 5v/12v supplies for the RR.


And I could probably finish this, too, if one of you cretins hadn’t hidden my DVM. Why, oh why do I clean up my shop? I can never find anything!

#25
Bob McCown said:
And I could probably finish this, too, if one of you cretins hadn't hidden my DVM.
Here it is! Under the couch! Remember when they were called VTVM's?
#26

Well, if I knew what the hell a DVM was I’d help ya look for it, …usually turns up in the last place ya look…:wink:

#27

Heh. It’s a “Digital Volt Meter”

Now, it seems to me that that’s sort of an archaic term, as I am not sure you could even FIND an analog one, much less a Vacuum Tube Voltmeter (good for high impedance readings)

As technology advances, these terms become quaint-sounding, I guess.

Oh well, time to go turn on the lights (we don’t turn wick adjusters any more, or switches) and crank up the music player (we don’t crank them anymore). Actually, I do listen to a 1910 Edison player. Remarkably good tone!

#28

I used to have a really nice analog volt meter with a large face. It will show you things that a digital never could. I can’t remember how, but I burned it up. Had a Heathkit VTVM too that ran off 120VAC. I got rid of that one when it zapped me. My DVM is from Radio Shack and is over 20 years old, still works!

You can still find VOMs for sale.

#29
Jon Radder said:
Had a Heathkit VTVM too that ran off 120VAC.
Heathkit.........now that's a blast from the past. I used to spend a lot of money there as a kid and built many, many kits :) Ralph
#30

Ahhh, good times. Well! No time for nostalgia. Gotta go work on my scale-model steam locomotive. :slight_smile:

#31

Memories, memories!

There is a Heathkit interest / support group on Yahoo. Pretty active even though the kits haven’t been made for a couple of decades.

I still have a nixitube digital clock in use in my hanger. I think I scrapped my Heathkit stereo amplifier years ago. OTH, it might still reside in the barn. It was a really great amp!

Happy RRing,

Jerry

#32

I’ve had a few questions about the construction of the signal head. What I use are 1 1/2" x 1/4" hole fender washers. You can get them in a pack of 100 for around $5. The LED holder is a metal panel mount for LEDs. I bought them on eBay for a few dollars for 100.

(http://freightsheds.largescalecentral.com/users/bob_mccown/Signaling/signalheadparts.jpg)

The hole in the washer needs to be drilled out about 1/32, and the panel mount screwed in to it, and snugged down. Since the washers are die stamped, make sure the rounded side of the washer faces front. Front:

(http://freightsheds.largescalecentral.com/users/bob_mccown/Signaling/signalheadfront.jpg)

Back:

(http://freightsheds.largescalecentral.com/users/bob_mccown/Signaling/signalheadback.jpg)

#33

But Bob,
I thought in your era of modeling, you would use “track torpedoes”. :slight_smile:

#34
Bob McCown said:
I've had a few questions about the construction of the signal head. The hole in the washer needs to be drilled out about 1/32, and the panel mount screwed in to it, and snugged down.
Bob:

A couple more questions:

Do you tap the hole in the washer, or just ‘force’ thread the fitting into the enlarged hole?

Do you use any mechanical fastener to attach the target to the mast? I would think a pin or rivet would really reinforce the joint. You mentioned using JB Weld. Could you provide details on how you do that?

I love the simplicity of your design and construction. Should provide a very robust signal.

Thank & Happy (Well Signaled) RRing,

Jerry

#35

Jerry: I just ream out the hole until the fitting fits. Its about a 32nd or so. No mechanical fastener, just the JB Weld. Ive used JB Weld on various bits on my race car, I think it’ll hold up on the signals.

Ill show more detail the next set of signals I finish up.

#36

Signal logic test. Sorry about the audio pops, and that I ramble.

[youtube]http://www.youtube.com/watch?v=eQfO8LqjCLI[/youtube]

#37

And a peek at the UI for the logic. Its based on a US&S CTC panel, with graphics from around the web.

(http://freightsheds.largescalecentral.com/users/bob_mccown/Signaling/ctc_1.jpg)

The levers work to set the signal aspects, and the indicators on the panel work depending on the aspects of the signals.

#38

I’m sensing that TrainOps 2012 will be a bit different…

#39

Dunno if theyll be installed by then… Maybe just at the yards. Still details to work out…

#40

You sound like Bruce Chubb