Post by: nodcc4me on January 30, 2017, 10:08:42 AM
https://www.amazon.com/PHC-APS-415-Variable-Supply-3-15vdc/dp/B00RKNQ2K2/ref=pd_lpo_23_tr_t_3?_encoding=UTF8&psc=1&refRID=946RCGQE4CPMG31ZRX5J
http://www.ebay.com/itm/30V-5A-US-110V-DC-Power-Supply-Regulated-Adjustable-Dual-LED-Digital-Lab-Grade-/201724897973?hash=item2ef7bdaab5:g:YDIAAOSwo4pYb2ed
Post by: Alan on January 30, 2017, 10:26:10 AM
Use a generic 15V wall wart like this: http://www.ebay.com/itm/Universal-DC15V-2A-Power-Supply-Adapter-110v-220V-AC-to-DC-15V-2000MA-Charger-US-/322374734303?hash=item4b0f0811df:g:oMkAAOSwopRYZpBX (http://www.ebay.com/itm/Universal-DC15V-2A-Power-Supply-Adapter-110v-220V-AC-to-DC-15V-2000MA-Charger-US-/322374734303?hash=item4b0f0811df:g:oMkAAOSwopRYZpBX)
or a cheapo SMPS like this: http://www.ebay.com/itm/Switching-Power-Supply-Module-15V-2A-2000A-AC-DC-For-Visual-Doorbell-Power/331994216209?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D2220071%26algo%3DSIC.MBE%26ao%3D2%26asc%3D20131003132420%26meid%3D94416848d9d149079ed6fbd6b1945e9d%26pid%3D100005%26rk%3D6%26rkt%3D6%26sd%3D322374734303 (http://www.ebay.com/itm/Switching-Power-Supply-Module-15V-2A-2000A-AC-DC-For-Visual-Doorbell-Power/331994216209?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D2220071%26algo%3DSIC.MBE%26ao%3D2%26asc%3D20131003132420%26meid%3D94416848d9d149079ed6fbd6b1945e9d%26pid%3D100005%26rk%3D6%26rkt%3D6%26sd%3D322374734303). Put it in a plastic box so you don't get shocked.
Post by: nodcc4me on January 30, 2017, 01:55:19 PM
Post by: Alan on January 30, 2017, 02:14:08 PM
Post by: nodcc4me on January 30, 2017, 02:20:21 PM
Post by: Alan on February 02, 2017, 11:01:47 AM
Post by: nodcc4me on February 02, 2017, 12:01:12 PM
The Trainpack has a speed control lever that has no effect on the track voltage, So it must change the current. Yet it has no effect on the RP equipped loco, which is being controlled by the LM module. Does that sound about right?
Post by: Alan on February 02, 2017, 12:53:53 PM
Interesting read. I hooked my meter onto the test track. The old MRC Trainpack was initially putting out 13v. I placed a locomotive on the track and the voltage remained the same until I turned on the prime mover. Then it dropped to 10-11v. The HC Sim was showing a low voltage error, as it should. I'm thinking the regulated wall wart won't drop like that and will solve the problem.
The Trainpack has a speed control lever that has no effect on the track voltage, So it must change the current. Yet it has no effect on the RP equipped loco, which is being controlled by the LM module. Does that sound about right?
Other than a few Tyco train set power packs, the only MRC power pack I have experience with is the old Model 500 of which I had several. My response is based on that experience.
Sounds right... to a point. An unregulated and unloaded 12v rated power supply will measure 13v or more often 13.8v. As long as a minimum voltage is maintained (somewhere around 9v), the LM functions. Unlike your Trainpack, a LM uses pulse width modulation to control speed. Pulse frequency, not voltage (directly) dictates speed. The LM is compensating, so to speak, for the position of the Trainpack lever. I would expect to see the voltage fall below the minimum LM requirement when the speed lever is moved to zero or near zero. Old school train power packs had rheostats with not much resistance difference between full on and almost full off. This was because of the required minimum starting voltage to get trains moving. The rheostat wiper would be completely off the winding when in the full off position. It's possible that even at the lowest speed lever setting there is still not sufficient resistance in the rheostat to prevent the LM from falling below its minimum working voltage.
Fun fact: My old 500's had impulse power. The switch simply changed the diode arrangement from bridge rectifier configuration to single diode half wave configuration. That baby really buzzed (at 60Hz to be exact) when the switch was set to impulse. As a kid I used to imagine all the buzzing going on were my prime movers working hard. Ah, simpler times. ;D
A regulated wall wart will have some minor voltage fluctuation with a change in loading. They are cheap consumer devices, not precision instruments. However, the change will be minimal compared to your unregulated Trainpack and should have no measurable effect on loco operation. The key advantage for you is wall warts are available in 15v which is picture perfect for RP.
Post by: Alan on February 02, 2017, 12:57:59 PM
Post by: Alan on February 02, 2017, 01:51:36 PM
Quote
The Trainpack has a speed control lever that has no effect on the track voltage, So it must change the current.
Your Trainpack is an unregulated power supply. It is a passive device. The voltage and current change (inversely) depending upon load and rheostat position. The article is about regulated power supplies only. The article applies to wall warts.
Electrically, this is your Trainpack and a locomotive:
With R1 being the speed lever and R2 the locomotive. R1 changes with lever position, R2 changes with loco speed and load. Ohm's law states the circuit current is determined by R1 + R2. It also states voltage drop across R2 = V - R1 drop. Since both R1 and R2 continually change as you operate the train there will also be changes in voltage across and current through R2 - your locomotive.
A regulated power supply will either: A) maintain a constant voltage regardless of R2 value; or B) limit the total circuit current to the value produced by R2. Voltage regulation is important to RP. Current regulation is not needed in the power supply as the LM already does this (loco stall setting on your HC). It is a misnomer of sorts to say current regulation. It is more accurate to say current limiting. Any device will only pass as much current as its internal R determines. Current regulators are for use with devices that have low R but not the ability to handle the current (heat) that such a low R would produce. LEDs are prime examples. Model train motors are bulky sturdy devices with the ability to dissipate a lot of heat. They only have a problem dissipating heat from excessive current when the R falls to very low. And even then it takes time for the heat to build up. The HC stall setting, AKA power supply current regulation/limiting, keeps the current below the critical point for the loco motor during low R instances (stalled or extreme loading).
Does that help?
Post by: nodcc4me on February 02, 2017, 02:51:02 PM
You are correct that the voltage does drop off near zero, but in my case it varies both high and low during normal operation making the prime mover start and stop annoyingly.
Post by: Alan on February 02, 2017, 04:23:05 PM
Post by: Jamesy on February 10, 2017, 12:51:23 AM
Yes, very effective pre workouts for men (https://www.muscleandfitness.com/supplements/best-pre-workout-for-men/) Alan. Thank you. This is a picture of the N-scale Trainpack, which is identical looking to my HO version:
You are correct that the voltage does drop off near zero, but in my case it varies both high and low during normal operation making the prime mover start and stop annoyingly.
That's nice, I like the lever on the side.
Post by: nodcc4me on February 21, 2017, 05:24:29 PM
Thanks again Alan!
Post by: Alan on February 24, 2017, 02:05:39 PM
Quote
As a follow-up, I ordered the wall wart. Problem solved, and it doesn't buzz like the old MRC. :D
Happy to hear problem solved.
Post by: WilliamWilliams on July 01, 2019, 07:07:10 AM
Found a picture online. Conjured up great memories for me from a long time ago. Reminded me again why I play with trains today.Oh wow! It reminded me also. I love this. Thank for refreshing my memories.
Post by: Tunmtr on July 13, 2019, 09:05:22 PM
Post by: nodcc4me on July 13, 2019, 09:19:46 PM
Post by: AnthonyBrunner on July 21, 2019, 08:38:21 AM
WOW after seeing this gadget my memories have also been refreshed. It reminded me of my childhood days when my father was using it.Found a picture online. Conjured up great memories for me from a long time ago. Reminded me again why I play with trains today.Oh wow! It reminded me also. I love Agoc Travel (https://www.agoctravel.com). Thank for refreshing my memories.
Post by: Nanthai 02 on August 12, 2022, 05:53:09 PM
Post by: gregeusa on August 14, 2022, 04:18:22 PM
Post by: carpediem4570 on October 03, 2022, 07:38:12 PM
I just bought a rolling track to use as a test track, in Ho. I thought one had to use the pwr56 as the power source to program the engines. You are saying one can use a wall wart for power and use The hc2, to program the engine without issue?
To take this one step further, can I solder the leads from the wall wart to my track and use this for power, using the hc2 to run my locomotives?
Excuse my ignorance. At 63, I am trying to broaden my knowledge of electronics.
Kind regards,
Max
Post by: G8B4Life on October 04, 2022, 12:45:14 AM
I just bought a rolling track to use as a test track, in Ho. I thought one had to use the pwr56 as the power source to program the engines. You are saying one can use a wall wart for power and use The hc2, to program the engine without issue?
To take this one step further, can I solder the leads from the wall wart to my track and use this for power, using the hc2 to run my locomotives?
Yes, and Yes. RailPro uses PODC (Plain Old DC) so a wall wart that outputs DC at the appropriate voltage will power your RailPro locomotives, however you need to be mindful of a few things, namely:
- Output capacity. Most generic wall warts aren't going to have much more capacity than 1 to 1.5 amps, you won't control much with that.
- Regulated or not regulated. If you want to use a wall wart for powering RailPro the wall wart should be regulated. This means as you use more power the output voltage stays the same. If it isn't regulated you could expect the voltage to drop quite a lot when you actually run locomotives, or the voltage to be significantly higher that stated without a load present.
- Output voltage. Needs to be in the safe range for RailPro. Again the point about regulation needs to be bought up.
- Tim
Post by: gregeusa on October 04, 2022, 10:51:23 AM
The improvement in operation using a regulated supply is noticeable in most cases, and often an unregulated supply can cause issues, as this thread dates from 2017.
Post by: faithie999 on October 04, 2022, 04:48:28 PM
https://www.ebay.com/itm/303178417154?hash=item4696d78402:g:DOwAAOSwcaFZH2wT&amdata=enc%3AAQAHAAAA4DRL94%2FZXD3nxj%2BKXAN88CpY88JG8y2VKpvIy8wV%2BFhNaw%2BAZZt1hL8phIlyqS4bhiiI%2Bq8hOzD46bN3vDhWn1rzZXI%2Fq%2FRxXC14%2Fuw%2BjTHsKNJjdl1yv0pHLKK%2Bn%2B7YkWpngZ67imhiynwMEwm10BCfxbe96dcLhDIuYyPkYAhvyGsZPO4ZpORxOccry4C67wiKh%2FmDlprq6e6%2F2R6wNwLXq6uX2VWC%2BhKziuM4wAFY%2F1ztrJ5IRH8krLzvAcDfXl7LK1Bk3ugKN5RHbgi0ga2ncAAzA70RU83oJhGikxbT%7Ctkp%3ABFBM6Li3z_Rg
Post by: Reena 04 on October 14, 2022, 02:21:54 PM