I come from New Zealand
I am thinking to buy new MRC e.g http://www.modelrectifier.com/search/product-view.asp?ID=1296or for my layout (N Scale) but I just find out MRC's website there are no 16AC for peco switch machine
which one right one power supplier for 16AC peco machine ?
P.s Only DC not DCC
Hi, greetings from Canada! I am using Railpower-1370 powerpacks (they have MRC's name on the box) for my HO layout. They may be available in NZ. With 4 installed, and with 1-2 more to come, they are working well for me thus far. I think they are rated at 18Watts (VA to the purists), and have an AC output. I use the AC to feed my home-brew CD unit that fires my Peco motors (also Rix, and Atlas motors & relays). My only troubles were when new: the screws on the AC terminal board are so long and slightly flattened that they can contact the heat-sink inside the unit, and if left unattended will blow it. The fix is simple. Since these units as purchased didn't have a warranty in Canada, I Dremel-ed a slot in the end of a regular screwdriver to remove the case screws, then removed the terminal block and ground off the excess length of the offending screws. The flattened ends prevented me from just backing the screws out to do the job. I suppose you could grind them off in-situ, but the idea of filings flying around a circuit board gives me the willies!
Real estate constraints at the control panel is leading me to consider building "The Throttle" mentioned in a post during the last month. That will give me walkaround capability and clear the table. It looks like a good circuit.
Even if used without a walkaround, I have no problem in recommending the 1370's.
Have fun, George
Hi BigG
MRC's website "Railpower 1370 powerpacks" not much information how many VDC and VAC they have ?
14.8 VAC too low (not strong enough) and other too high 18.5VAC for peco switch machine will burn out that right ?
If what you are wanting to power is just the peco switch machines why not just buy an AC power supply in the voltage you need, with enough current capacity to handle your application with some room to grow?
You will probably want a regulated supply that will not deliver higher voltages when current draw is low.
On the other hand. If you need 16VAC and you have 18VAC just add some resistance to the circuit to bring the voltage down to acceptable levels.
Even if you are looking for a powerpack many MRR's have switched to using a separate power supply for turnouts and accessories in order to leave the power pack for running trains. I intend to use an old computer power supply for accessories and a separate power pack that will power my turnout switch machines.
The Railpower-1370 120VAC/60Hz-input model lists on the box: 15VDC, 19VAC, Total output 18VA.
I assume the 220V models are similar, but check first. I am using a CD unit to hit the Pecos- and other magnets-and-relays. The unit's output is in the 27VDC range which falls off rapidly to a couple of volts if you keep the power applied to the magnet(s); that is the beauty of the CD unit. It sips at the input voltage of 19VAC, charging a nice big capacitor and dumps it to the magnet on demand. The rapid falloff of voltage and current means that you won't fry the magnet if you are slow to get off the button. I don't think using a stall-type of switch motor like a Tortoise would be a good idea here, as they only draw a few mA and the CD's charge rate would overwhelm it. Feed them 12VDC directly from the supply. An additional benefit of using the DC pulse is you don't get the buzzing in the magnets.
I'm not familiar with the power requirements of N-scale Peco motors. My HO size model PL-10E are quite happy doing their thing with what I feed them. Remember, no matter which scale you use, or what supply, the power is applied for only a second or two at most, or you will get overheating. If using a CD unit, it needs to recharge the capacitor after each use. Some are quicker than others; mine needs only 1-2 seconds depending how far it discharged for the differing magnets I have.
I hope I have given you what you need. If not, let me know and I'll try again..
Have fun.... George
Oops! I neglected to mention some info on CDs you can read. Do a search on Capacitor Discharge Unit at the top of this forum. In the many threads are references where to find info.... G
BigG wrote:I don't think using a stall-type of switch motor like a Tortoise would be a good idea here, as they only draw a few mA and the CD's charge rate would overwhelm it. Feed them 12VDC directly from the supply.
From what I have learned about the stall motor types like the Tortise...no the CD unit would not work. The initial ZAP may be more than the stall motor wants but the the big difference is that unlike the twin coil switch machines that burn out if the power is applied for too long, the Tortise etal needs power applied after the fact to maintain pressure on the turnout point rails.
Loathar:
Within the scenario of magnets, it will be the actual current thru the coil that is important. The maximum current will be defined by the size of the wire... too much current will blow the wire like a fuse. That means that the voltage is a concern too, and is the easiest for us to measure. Pumping DC thru the coil will pretty-well give you a current like a resistor, where the resistance is only that of the length of the wire and is pretty small. Hence the high DC current. AC on the other hand brings in something called inductance, which can be considered as AC Resistance. For the same length of wire, the magnetic properties of the coil become important, and the AC-resistance in a coil, especially one with an iron core will be much higher than the DC resistance of the wire. That's why you need to be more careful when feeding DC to a coil, than if using AC.
I think we might be getting a bit off-topic from the original exploration of MRC pwr packs, but all this is relevant. I fried a couple of Atlas magnets using AC too easily for my liking, so that's why I went the CD route. Now I can be as fumble-fingered as I am and get away with it! :+)
Still having fun...... George
The voltage for the Peco switch machine is not particularly critical, as long as it is momentary. Anything from about 12 volts to 24 volts will work, AC or DC, again in only a short burst. This is the big advantage of a CD unit in powering twin coil switch machines - the current falls off very rapidly as the capacitor discharges, regardless of how long you hold the button down.
Unless you have a really high power rating (VA or watts) on the power pack, the voltage to the switch machines is going to drop under load anyway. And if you use the same power pack to run trains, you may notice a momentary drop in train speed when you throw a turnout. Again, a CD unit takes care of this problem as well, using a smaller charging current with a longer duration than the discharge into the switch machine.
yours in power
Fred W