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1 comment and 3 questions...

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  • Member since
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  • From: Ridgeville,South Carolina
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1 comment and 3 questions...
Posted by willy6 on Monday, September 1, 2008 10:48 PM

I went to electronics school years ago while in the Navy. At that time they were still teaching vacuum tubes, basic transistor theory, braided core memory and MDF file computers, so now that I have showed my age, I have some modern electronics questions.

   Tortoise Machines, I want to use 10 on my layout and LED's on my control panel, what is a good power supply, 12VDC/1000ma or something else?

    Power Supplies, I was looking through my JAMECO catalog for DC power supplies and they have "Regulated" and "Unregulated"...what is the difference?

     Photocells, I know how they work. The confusing part is they are rated in OHMS to go ON or OFF. I need some that are open/off in a dimly lit room and closed/on when dark. What resistance values should I be looking for?

 

Being old is when you didn't loose it, it's that you just can't remember where you put it.
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Posted by Capt. Grimek on Monday, September 1, 2008 11:43 PM
willy6,
I don't know the correct specs. but if it helps any, there is a specific power supply "wall wart" sold for the Tortoise switch machines that powers up to 30 of them, for about ten to eleven bucks.
cchobbies.com has them as I just ordered one today. (cherry creek hobbies in WY.)
Sorry, I don't know what the specs. are on them.

Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.

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Posted by BlueHillsCPR on Tuesday, September 2, 2008 12:11 AM

 willy6 wrote:
   Tortoise Machines, I want to use 10 on my layout and LED's on my control panel, what is a good power supply, 12VDC/1000ma or something else?

12VDC @ 1000ma will be plenty for ten tortise machines.

The Circuitron adapter is rated at 12VDC @ 500ma.  Circuitron states it is enough to power 30 Tortise switch machines.

Power Supplies, I was looking through my JAMECO catalog for DC power supplies and they have "Regulated" and "Unregulated"...what is the difference?

As I understand it, a regulated 12VDC power supply will output aproximately 12VDC regardless of the load in amps or milliamps that is placed on the supply.  An unregulated supply will output more than 12VDC if it is not loaded sufficiently.

Sorry but I can't help you with the photocell ratings. 

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Posted by cacole on Tuesday, September 2, 2008 7:41 AM

From the Tortoise data sheet:  This system uses the most basic power source, a simple DC supply of not more than 12 volts.  Lesser voltages will make the Tortoise run slower (and quieter).  The power supply need not be filtered.  Each Tortoise will draw 15-16 ma. at stall, so 30 switch machines can be powered by a single 9 or 12 volt, 500 ma. wall plug adapter .

The photocell resistance is not going to be as critical as their controlling circuit sensitivity.  Photocells work on the principle of resistance change with change in light intensity, so the circuit you're controlling will have to have components that can react to a very slight change in that resistance, and the circuit will need to be adjustable through pots to the differences in photocell sensitivity because there are slight fluctuations in their values even if they all have the same rating.

If you perform a Google search under the term "photocells" you will see that they come in a wide variety of sizes and resistances.  You'll probably have to conduct a lot of experiments with several different photocells to get the right value.

Personally, I always use side-looking IR emitter-receiver pairs aimed across the track to detect trains on a layout and trigger crossing signals, etc. because the amount of ambient light in the room makes no difference to them.  These devices are so small they can easily be disguised.

 

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Posted by gandydancer19 on Tuesday, September 2, 2008 5:22 PM

You might also want to check out CSD cells.

If you are thinking about getting into layout automation, check out cti-electronics.com.  If you are using Digitrax DCC, they have some really good accessory boards.

Here are some good electronics links:

They are in no particular order, but the first three are surplus companies so they don't have everything all the time.

http://www.allelectronics.com/

http://www.mouser.com/

http://www.skycraftsurplus.com/index.asp

http://www.mpja.com/

http://www.alliedelec.com/

http://www.digikey.com/

http://www.bgmicro.com/index.asp

http://www.jameco.com/

My initial training was on tubes also.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

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Posted by tinman1 on Wednesday, September 3, 2008 12:36 AM

I think the navy still teaches tubes. Cheap butts.  Anyhow, I had a link bookmarked that might help you out. http://home.cogeco.ca/~rpaisley4/CircuitIndex.html#Light

It contains several different circuits for different outputs. Hope it helps                       

Tom "dust is not weathering"
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Posted by NJWATERGUY on Wednesday, September 3, 2008 1:15 PM
Tinman1 beat me to it, Check out that website for model railroad electronics. Theres enough info to build yourself but rob paisley also sells circuit boards and kits which are real nice.
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Posted by tinman1 on Wednesday, September 3, 2008 3:32 PM
After looking through that site pretty good and the discussion on the general forum about the sub, I am definately having flasbacks about neets mods.
Tom "dust is not weathering"
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Posted by allaircooled on Wednesday, September 3, 2008 5:24 PM

 tinman1 wrote:
After looking through that site pretty good and the discussion on the general forum about the sub, I am definately having flasbacks about neets mods.

 I have the neets mods on cd rom if you like.  Big Smile [:D]

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Posted by tinman1 on Wednesday, September 3, 2008 6:13 PM
 allaircooled wrote:

 tinman1 wrote:
After looking through that site pretty good and the discussion on the general forum about the sub, I am definately having flasbacks about neets mods.

 I have the neets mods on cd rom if you like.  Big Smile [:D]

NOOOOOOOOOOOO. no thanks.

 

Tom "dust is not weathering"

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