I've pulled out my model railroad stuff which has been sitting in boxes since about 1989. My sons are interested and fascinated by trains (we just took a ride on the Strasburg Railroad, visited the Choo Choo Barn and the National Toy Train Museum last week when we were in Pennsylvania). Anyhow, I thought they'd enjoy a small layout as much as I did when I was their age.
So I've cleaned up the rails and the wheels, and put together a small section to get started. Problem is, it seems that everything runs at one speed. However, I seem to recall that there was variable speed (yes, I did connect the track to the DC track connectors, not the AC).
So for sitting in a box for about 20 years, I'm sure the loco motors need cleaning/lubricating. But before I do that, I thought I should check the power packs.
What is the correct way to test the power pack to ensure that it is operating correctly? I've got a meter, so I can check it, if I know what the correct procedure is and what it is I'm supposed to be measuring. The output rating is 6 VA (Total) 18 VDC 20 VAC I'm not sure what those numbers mean. I've got some idea, but would like to hear from knowledgeable people to make sure my thinking is right.
Set your meter to the DC volt scale. Don't know what scale values are on your meter, but pick a scale above 12 volts DC. Turn controller down to smallest value (off). Connect one meter lead to each DC output terminal. With transformer plugged in and controller off, you should read no volts on meter. Move controller handle in increasing speed (voltage) direction. You should see meter move from zero upward to maximum output voltage. Note that if meter moves in the wrong direction, you'll need to reverse the leads.
Some questions:
What scale is this?
What brand of trains? Marklin HO trains use ac not dc.
What brand / model is the power pack?
As an fyi, some power packs have fixed dc and ac as well as variable dc connections, make sure you're using the variable set if you have a choice.
Good Luck
Paul
So the voltage is the variable. Does that mean amps is constant?
Is it simply a voltage test? Or should the amps be checked as well?
If there's not a lot of variation with the voltage as the throttle is increased, does that mean that the power pack is fried? Or can it be opened up and cleaned?
James Buss So the voltage is the variable. Does that mean amps is constant? Is it simply a voltage test? Or should the amps be checked as well? If there's not a lot of variation with the voltage as the throttle is increased, does that mean that the power pack is fried? Or can it be opened up and cleaned?
6 VA means the product of voltage and current (which is power out to the track in watts) will be at least 6. For example, 6 volts at 1 amp or 12 volts at 0.5 amp. Volts are a measure of "electrical pressure". All things being equal, more volts will drive more current thru the load. Zero volts is "off". 12 volts is the nominal maximum voltage applied to HO and N gauge track. At 12 volts, the locomotive will reach full speed. Most model train power packs will produce something more than 12 volts. In fact, the maker of your power pack claims that it will furnish as much as 18 volts direct current (DC) The DC output can be varied from 0 to 12 volts with the throttle. The AC output is fixed voltage, intended to operate switch machines or lights.
First check the pack under no load. The DC output ought to go from zero, to 18 volts as you move the throttle. Then place it under electrical load. A 12 volt light bulb is good and you can get them from the auto parts store. Ask the counterman for a nice small one that only draws 1/2 amp at 12 volts. The #47 brass bayonet base lamp commonly used in tail lamps pulls at least an amp. Try for a smaller one.
The power pack is good if it will light the 1/2 amp bulb at full throttle, and the throttle will reduce the voltage (dimming the lamp) by a factor of 10 or so.
If the throttle works properly under load, but not under no load, that's OK. Simple throttles used in train set power packs need a load before they work.
The "direction" switch should reverse the polarity of the DC output, to make the engine run in the other direction.
If your locomotives have been stored for years it may be the lubricants have gone sticky, and the motor needs full voltage to make things move at all. In this case you need to take the locomotives apart, clean the old lube out and relubricate.
David Starr www.newsnorthwoods.blogspot.com
Yes, the voltage is variable, from 0-12 (approx). 6VA = 6 volt-amps. Meaning it'll provide 6 amps at 1 volt, 3 amps at 2 volts, or 1 amp at 6 volts, or half amp at 12 volts. It does *NOT* always put out maximum current, the amperage is available for locos to use, the locos current draw determines amp usage. Which, by the way, only 6 VA is really only enough for one (*maybe* 2) locos in HO scale. Sure, it may run 2-3 at low speeds, but crank open the throttle and it may not have enough power at higher voltages.
You should get a nice smooth transition of voltage from 0-12 (or 18? in your case). Assuming you do have a nice smooth transition, try the check with the loco on the track. It's possible the power pack shows OK with no load, but does weird things under a load. If the voltage range still checks out, then it's time to check the loco. Some of those older, inexpensive locos didn't have good low speed performance at all, they would run OK at mid-range speed. Also, some of the older ones tended to draw a lot of power, possibly more than your power pack can handle (at higher settings, anyway).
If the power pack is giving bad readings, most of them are *NOT* user serviceable, they are sealed or not intended to be opened. Meaning - time for a new one.
Brad
EMD - Every Model Different
ALCO - Always Leaking Coolant and Oil
CSX - Coal Spilling eXperts