My question is: with only 600 ma how much power can it possibly deliver? How many Tortoise machines will it work at one time? And how many 12 volt lights will it work while at the same time it is operating the Tortoise machines? I would have thought you might need something in the 4-5 amp rating.
600ma is the same as saying six tenths of one amp, which is a very minimal output at 12 Volts.
Light bulbs typically draw around 30 ma each and a Tortoise draws something like 15 ma at stall, so you can do the math.
Keep in mind, however, that it’s usually not safe to operate the power supply at full rated load, so a wall-wart with a higher amperage rating would be preferred. I use a computer power supply with outputs of 5 and 12 Volts at higher amperage ratings so there’s no chance of an overload.
I am actually using four wall warts to power lights , etc. By breaking up the load among the four I don’t overload any one unit. I have them plugged into a power strip that gets turned off when I cut the layout power main. Most of them are 1 amp each, thats a bunch of light bulbs.
Tortoise motors only draw about.018 amps at full stall. Thats 33 Tortoises! As far as small 12 volt lamps - it will vary. I have several old ‘wall wart’ power supplies that I use for bldg lights.
No no, it’s not WalMart, it’s Wall WART. A generic term for the little black plug-in power supplies that the whole box plugs into the wall and has a wire coming out of it with the low voltage. Since they sort of look like warts on the surface of the wall…
You certainly can buy them at WalMart, but they are also found just about anywhere.
You are talking about some type of AC to DC adapter correct? Not a small charger like I use to charge cell phones or walkie talkies? They are small and plug directly into the wall outlets also.
Take a regular 9 Volt battery and use it to drive a Tortoise. You will find that you can drive a Tortoise all day with that one battery. We consider batteries to be annual purchases because with a good Recharger and quality batteries we dont need to buy new ones everytime the old ones run down anymore.
Our batteries last so long they get replaced when they fail to hold the chemicals inside or perform for a minimum time.
You can buy Wall Wart power supplies quite cheap. That model Walmart is selling is variable across several voltages and is higher priced. Even the Digitrax PS12(12 volts/300 ma) can be bought in the $7 range. Do a ’ Google’ search on ‘wall wart 12 volt’ - You will find lots of stuff out there. You can get 12 VAC/500 ma wall warts for something like $2.99 each!
They are all Wall Warts. Just most of the phone charger type don’t put out enough current and/or voltage to be useful for our purposes. But if you have a leftover, check the label before tossing it. 9-12 volts, 250mA can drive 10 Tortoises no problem.
Bill, the two are one and the same! That ‘small charger’ contains a small AC transformer and a rectifier circuit - just like a model railroad power pack (except for lack of voltage control.) In fact, the device in the Wal-Mart e-catalog is intended to be a charger, which is why it has that bunch of connection adapters.
Wall warts left over from defunct electrical devices are a very common item in many households. I, personally, am using the charger that came with a long dead cordless drill to power my switch machines (2 coil, capacitor discharge circuit.) They all have rating info on them, so it’s easy to pick a suitable one.
According to Circuitron’s instructions, each Tortoise draws 15 to 16 ma at stall, so theoretically you could power 37 with a 600ma power supply. BUT, as previously mentioned, you really don’t want to overload it, so 25-30 would be safe.
You may also note that the Tortoise doesn’t necessarily require 12 volts. Many of us use 9 volts, since we like them to run a bit slower. They’d run on 6, but that’s too slow for me.
I have about 50 on each of a pair of 9v 800ma wall-warts from Radio Shack. They’ve work ed just fine for years.
And I agree with another post, that it’s usually better to use a separate power supply for lights. As you add Tortoises, it’s easy to figure the total load; but adding lights is often a different story. You might start with one supply, but plan to separate them later.
I use a separate power supply for my lights, and several pots (rheostats) to vary the brightness of lights, usually in groups. Some were too bright, some too dim. Once I got them set right, I added several more, and they all dimmed a bit, and required re-adjustment.