I’m at the wiring stage in my layout. Currently I am working on the staging area and three trunouts leading to the staging area.
I have duel color (red/green) LED’s aligned with each track to show direction, diverging or straight through. There are six LED’s for the turnouts.
I also am using toggle switches for each of the eight staging tracks to turn them on and off as needed. I have one duel color (red/green) LED for each staging track to show whether it is off or on.
I have one 12V wall wart to power the three tortoise machines and all 14 of the LED’s.
I haven’t powered everything up at once yet.
My question is will the one wall wart be enough or do I need to use two or three power sources (wall warts) to power the three tortoise machines and 14 LED’s?
It depends on the amperage your walwart is capable of delivering. Some are rather low. Add up the current draw of your Tortoises and the leds and see if it is within or exceeds the capacity of your wallwart. I would then figure in a 50% security blanket. I agree with Jeff that it is best to add a layer of security and you may want to expand in the future[:)].
Every wall wart has a current raring as well as a voltage output. If your wart has enough oomph to handle all the load, then only one will do. If yours has a rating of 200mA or more, it should work just fine.
I do not personally like to use old wall warts. They were innefficient and got hot even when not loaded. A definite fire hazzard. Leave yours plugged in for a while with nothing connectrd and see if it gets warm.
I use a computer power supply, which can deliver 12 Volts for the Tortoise switch motors and 5 Volts for LEDs, signals, and road crossings flashers. One such supply can drive hundreds of Tortoise machines and several hundred LEDs.
Tortoise switch motors only draw about 17-18 ma each. I assume you are wiring the LED in series with the Tortoise. As others have metioned, the output rating is on the ‘wall wart’. I have a 13.5VAC wall wart rated at 800 ma that I use for my Tortoises. That is something like 44 Totoise motors! I only have 10 Tortoise motors, so I feel pretty safe. I just wired up one side of the clubs staging yard and a pari of cross-vers that lead to it. 14 Tortoises on a 15VAC/500 ma Minitronics wall wart…
The 9V 300ma is ok for the Tortoise. The LED’s are another matter. Too many LED’s for one wal-wart (ww). If not in series with the Tortoise they will also require dropping resistors.
Their is also a matter of voltage drop. With every LED you put in, about 1.8V to 3.3V per LED is dropped. So 5 active LED’s is about the max you can run per 9v ww depending on the V drop of the LED. Since your saying dual color led, I assume one color would be on all the time also.
What you’re saying is that I need to use the 12V, 300ma wall wart for the eight LED’s I have for the staging area since the LED’s will be on all the time. Use one 9v, 300ma wall wart for two of the tortoise machines that will aslo have 4 LED’s attached and they will be on all the time as well. Use the second 9v, 300ma wall wart to power the third tortoise machine and the 2 LED’s that go with it. Correct?
Personally, I don’t think 9V will run a Tortoise reliably. And especially not if you put a LED in series with it. There is plenty of amperage in your 12V supply to run all your LEDs and Torti as well.[2c]
LED’s in series with the Tortoise are not going to draw any more power. The only thing you must deal with is the voltage drop of the LED. Bi-color LED’s drop between 2-3 volts, so only 6 or 7 volts is will be available to the Tortoise. It will move the points ‘slower’ for sure, and there may not be enough power to reliably get them moving. A little test will answer that question.
I use a 13.5VAC wall wart and a couple of large diodes to make a ‘polarized’ power source with plus, minus, & common(per the last example in the Tortoise doc). 12VDC will move the Tortoise even with the LED in series with it.
Let’s be specific about the effects of wiring the LEDs in series or parallel. (Jim B I think you meant no additional voltage concern if they are wired in parallel. Series would be back to back to back, etc, rather than all off common anode and cathode. Or do I have it backwards? [xx(])
You can run a h*ll of a lot more than 8 LEDs off of a 12V wall wart.
Here’s a pic of my industrial complex with something like 25 LEDs, all on 1 small wall wart:
Or my shop with 6 LEDS off of 2 AA batteries (3V) Note the common wiring - all black wires together, all white wires common. (JIm B - parallel or series ? [:D])
The real factor in the number of LEDs you can run off a power supply is the amperage of your pwer supply. Each LED uses about 20 mA (milli-amps) and they add up. But if wired parallel, the voltage “drop” isn’t really relevant.
Another factor IS the draw of each LED compared to another wired with it. LEDs don’t share amps nicely and the highest drawing LED will hog amperage, preventing other LEDs in the same circuit from lighting. In the complex above, the yellowish LEDs are wired separate from the white Surface Mounts, which are separate from the white T1’s. But they are all off of the same 12v wall wart.
It will work very nicely as a matter of fact. I have 3 9v 300 mA supplies each with close to 20 Torti on them. 9v runs a torti both reliably and realistically. When I have one or two LEDs wired in series with a torti, I use a 12v power source.
It is an addapter usually used for things such as a calculator, cordless phone, cell phone charger… I have two that came with our old cell phones that are 9v 300ma and one 12v 300ma that came with an old cordless phone.
I did a test after reading all the suggestions. I used my 12v 300ma wall wart and powered everything at one time. Yes all the LED’s are in parallel.
All the lights work fine and the tortoise machines all work great. Here’s a picture
The tortoise machines are on the left and you can see the lights are lit as well as the staging area.
I kept the lights on for several hours to see if the wall wart got hot but it only got slightly warm to the touch.
TORTOISE’s are 3 volt DC motors geared down. The resistor keeps the current to a ‘trickle’, holding the turnout points in place against the stock rail.
I imagine the internal electrical contacts are independent for indication or power routing.
Running @ less than 12 V. makes it run slower. Higher V. makes it run faster, but probably increases the ‘stall’ current. Theoretically, one could run any voltage with the proper resistor.
Unlike 'Twin coil types, these ‘Stall motor’ types require DC.
I have a whole box full of old wal warts. I pulled 6 of them out to check with my meter. Only 1 out of the 6 actually read what was listed on the label. Most read much higher.
