For a small,test section i am useing a old transformer to operate my under the track kadee’s.It works well on this 8’ section.My layout is a 20’x20’,around the wall,shelf layout,which means that if I put the power supply in the middle, I could possibly be as much as 40’ away from a uncoupler.Do I look for a power supply with higher amperage? Do I run a 14guage power buss all around the layout?Do I use 3 or 4 12v power sources to avoid power drop to the un-couplers?
I’d go with the thicker wire. My guess is, though, that the voltage drop will not be enough to make the uncouplers unreliable. For this kind of thing, though, you might want to find an old 12-volt wall-wart. Also, consider where the pushbutton will be placed. If they’re all in a centralized panel area, then it won’t help to have small distributed transformers close to the uncoupler, because the line to the button will still be just as long.
Do you have any coils of hookup wire sitting around waiting to be used? Connect up the uncoupler through the wire coil, and see how it works. That will give you some idea of how much a long cable run will affect you.
How do you like them, by the way? I’ve got one that I haven’t installed yet. Mostly, I use between-the-rails permanent magnets for sidings, but I plan to use electromagnets on the main line to avoid the occasional accidental uncoupling.
MisterBeasley…My layout is "walkaround"so I will always be close to where I am uncoupling.The power buss may be the way to go,I was trying to find the easiest,most effective way to power them other than running another heavy buss around the layout.I now have my DCC line,my Digitrax LOCONET,Tortoise power supply.It’s starting to get crowded and looking like my old block controlled DC layout wiring. The uncouplers work fine…I just have to find a way to power them for longer than a split second as I also have to operate the throttle to control the movement of the train.Pull over the magnet,press the button to open the couplers,pull foward while holding the couplers open, change direction,Activate the uncoupler to open them again and hold them open untill the couplers mate in the delayed position.It would be great if I could press the button so that the power stays on for a few seconds so that I could operate the throttle with both hands.
Mike,
Be careful about leaving the power applied too long. Unless they have changed them, I saw one get burned out due to the power being left on.
Jim
Maybe you could use either a toggle switch or a latching push-on, push-again-off button wired so that the uncoupler magnet is in parallel with a red light on the console. That way you’d know when it was on.
More than 1 way to do this.
MOST electo-magnets operate on AC or DC. The maker should specify the voltage.
(1)You can run a CENTRAL supply with a buss delivery system. Voltage drop can be measured with a cheap $8 meter. 18 gage solid is a good start. One can increase size to 16 gage economically. Loger runs drop voltage. 3 amps should be more than enough since you’ll be operating one at a time.
(2) Simple AC wall transformers are cheap, and when located close to the magnets would eliminate a lot of wire. Bell wire is fine.Again 2- 3 amps should suffice due to mometary nature.
ALL Elecromagnets can use a simple fascia mounted ‘doorbell’ button. The most important thing is they be MOMENTARY.
AC vs. DC: They both work. DC buzzes less.
I opened up my Kadee #307 electomagnetic uncoupler last night. The voltage rating is 8-12 volts. The instructions say not to leave it on for more than 2 minutes at a time. I plan to use a momentary-contact button on mine.
Does it buzz when it’s on? If it’s loud enough, then maybe you don’t need a light to tell you it’s on.
I have’nt noticed if they buzz or not,as I only use a momentary push button at this point.But I suppose it would work just as well with a toggle and the buzz would remind me that it is activated.I would think that my best bet would be some type of device that would shut down the power after a pre-set time(If something like that even exists)
TOGGLES with electro-magnet coils are a bad idea, because wires used in magnetic coils are very fine, and will heat up and short when current is applied for too long.
How long is ‘too long’?
Depends on time, voltage, current, and size of wire. MOMENTARY contacts (such as a doorbell) are generally not pressed long eough to burn out a coil.
I finished installing my Kadee 307 uncoupler today. Along the way, I had a few false starts, but I also took some measurements to hopefully do better next time.
These are rated at 8-12 volts. The instructions specifically say they will work on AC or DC, but will work better on DC. I tried powering the unit with an old power pack, both at 9 volts and again at 16, which is a bit much but it was only for a test. Neither worked very well. I found that when I pushed the button, my 9 volts dropped to about 4, and the uncoupler drew 400 millamps. With 16 volts, again the voltage dropped significantly, and I found that the next setting up on my meter didn’t work. So, these things are big power hogs, and need an independent power supply. I could see my LEDs dim when I pushed that button.
I ended up scrounging through a closet and finding an old wall-wart that was rated at 12 volts, 1 amp. It seems to do the job very well.
As a side note, I did this installation through 2-inch foam on installed (but not ballasted) track. It was a royal pain in the posterior. If possible, do the installation before you glue down the track.
On the bright side, once installed properly it does the job quite well, and does not interfere with my low-hanging P2K S1 switcher, which has notoriously low clearance.
Your Electro-magnetic Coils are taking more current than your (selected) power supply could deliver - that’s WHY the voltage dropped - (and the one Amp worked better). Same is true with twin coil switch machines - particularly if 2 are thrown simultaneously (same time).
“Power Hogs” - or a weak power supply ? Try lighting just a small 60 watt bulb with your power pak sometime.