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Using Old Chargers

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  • Member since
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Using Old Chargers
Posted by scott018 on Wednesday, February 3, 2016 7:25 AM

Was doing some house cleaning and came across that pile of old toy/phone charger pile. Anybody use them to light grain of wheat bulbs. The cord length is perfect for what I need, while the voltage varies between 3-6 output. I am figuring 2 maybe 4 in series pending on voltage output. Really am not looking for a real bright light just hate to toss them and like I said the cords are perfect.   Thanks much.

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Posted by mlehman on Wednesday, February 3, 2016 7:40 AM

Don't put them in series, just use each one's output as it is. 

Some may be AC, but the preferred ones are DC. You don't want to mix them by hooking them up together. But you also will have unpredictable results with mixing the outputs together. They're pretty safe on their own, so don't make them do extreme things they weren't designed for.

I generally avoid the AC ones, but they should work for lighting.

Consider that you get many more things lit if you use LEDs, without all the heat, etc compared to bulbs. Bulbs represent fairly high loads, so you'll only be able to string together a few before you reach the maximum amperage output each is capable of.

If you have some that are 9 to 12 volts DC output, they work great for powering Tortoise and other stall motor type turnout motors. I use the lower power DC ones for structure lighting circuits.

Mike Lehman

Urbana, IL

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Posted by rrinker on Wednesday, February 3, 2016 9:49 AM

 Just pay attention to the current rating as well as the voltage, and don't overload them. The super-cheap kind have absolutely no protection and will just get really hot if you overload them, up until some component finally fails. The slightly better ones have a fusible link inside which will open if overloaded or if the outputs are shorted, and there's no way to fix it.

               --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by carl425 on Wednesday, February 3, 2016 9:51 AM

mlehman
Don't put them in series, just use each one's output as it is. 

I may have read it wrong, but I thought he was talking about the bulbs in series, not the power supplies.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by scott018 on Wednesday, February 3, 2016 4:04 PM

Yep that's what I was thinking of. Just 3 or maybe 4 bulbs in series just enough to get a little light. Will have to experiment around a little.

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Posted by Soo Line fan on Wednesday, February 3, 2016 6:40 PM

Some negatives as well.

  • No on/off switch.
  • No fuse or a one time sealed fuse
  • Odd voltage values
  • If using a series circuit, and a bulb goes out, all the lamps are out.
  • Series lighting is harder to find the inoperative bulb.

I throw these away unless they can be used for a actual charger. A single or dual throttle cheap DC pack can used instead. The throttles can be set to different voltage values, AC and DC fixed also provide options.

 

Jim

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Posted by Mark R. on Wednesday, February 3, 2016 8:26 PM

Another factor to be seriously considered is whether the wall pack is a regulated power supply or not. 

A regulated supply will supply the stated voltage independant of what is attached to it.

A non-regulated supply will only supply the rated voltage if the appropriate load is applied to it - e.g. what it was made FOR. I've seen wall pack chargers that were rated for 5 volts put out nearly 12 volts with no load attached to it. That puts you on a slippery slope .... the more load you apply, the less voltage the unit will provide. Don't use these - throw them out. They were designed for a single purpose - to power what they came with.

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by Enzoamps on Thursday, February 4, 2016 1:10 AM

Well, an opposing view.  Unregulated supplies do spit out higher voltage than their rating until they are at the rated load.  But if you measure the voltage coming out, and load it with say four lamps, that load won't change, so if your 5v adaptor puts out 9v under lamp loads, then it will pretty much stay at the 9v unless you change the number of bulbs.  In other words, pay attention to the current rating, and ignore teh voltage rating in favor of your volt meter reading.

If you want regulated output, feed your 15vDC into a 12 or 5 volt regulator IC. SImple circuits are online.

The simplest way to find the open series lamp is to masure the voltage across each lamp.  All will have zero volts across except the open one.  That one will have the full power supply voltage across it.

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Posted by tomikawaTT on Thursday, February 4, 2016 2:33 AM

Two diametrically opposite uses of wall warts and equivalent.

I have a couple of old filament transformers, 12.6vac center tap, wich gives me 6.3 volt lighting circuits.  Using 2.5V (nominal) lamps, I put three in series for industrial/commeercial lighting of structures (and lights over my not-so-hidden staging yards.)  Four in series provides a nice yellowish glow for domestic lighting.

I also use a heavy-duty wall wart (charger for a now-defunct 18 volt drill) to power twin-coil switch machines.  I stripped the rectifier circuit, then put diodes in the control circuit so I can power either coil with half-wave DC - only one wire connects the panel to the machine, and the working coil gets about 12 VDC - RMS of the half wave.

The chargers/wall warts may not have integral switches.  That doesn't prevent plugging several into a power bar with a circuit breaker and an on/off switch.  And the output should have appropriate switches for the individual loads.

Chuck (Modeling Central Japan in September, 1964)

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Posted by Soo Line fan on Thursday, February 4, 2016 7:41 AM

Enzoamps
The simplest way to find the open series lamp is to masure the voltage across each lamp. All will have zero volts across except the open one. That one will have the full power supply voltage across it.

Absolutely correct. However, this requires you to crawl under the layout or remove the roofs or stuctures to gain access. It may be the first one you measure or the last one. If a single parrell light goes out its much easier.

Jim

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Posted by Enzoamps on Saturday, February 6, 2016 1:30 AM

Sure, it was just the solution to how to find a dead series bulb if you have a series arrangement.  If yours are parallel, it is moot.

I would recommend against series bulbs if they are not in the same place.  In other words, if I have four series lamps in a building, and one goes out, I have to take the roof off no matter what to get at the dead bulb, series or parallel.  If they were in series with one in the building, and one in the light pole across the street, etc, that would be a pain.

I guess it also depends upon your orientation, I am an electroncis professional with some train experience, which makes my approach different from a solid train guy with a little electronics.

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Posted by rrinker on Saturday, February 6, 2016 10:50 AM

 I always wire parallel - and i don't do common rail to the track, either. While I DO have an EE degree, my model railroad experience started with HO before I was 3 years old, so I'm not sure how you would characterize my various experience levels. Though as a kid we never had a permanent layout, just one we set up every year from Thanksgiving to a little after New Year. The rest of the year my favorite toys were legos, Erector set, and a box full of batteries, wires, and switches - when I was 5 or 6, I found the train layout looking ready to at least run trains around, but when it got to the back, the train stopped. I crawled around and found the insulated joiners my Dad installed, and the unconnected feeder wires. Connected them up and had trains running when he got home.

 So, am I a train guy with lots of electronic experience (keep in mind that despite my degree, I only briefly worked as an EE before getting pretty much 100% into computer work, which remains my day job - electronics is just a hobby for me now) or am I an electronics guy who happened to get into trains? While I was going to all the local tourist railroads from a young age (I have some old slides I scanned I'll have to post in the prototype section), the bulk of my prototype knowledge has been accumulated since well after college. Hmm, does it even matter? Big Smile I like triand and I like electronics, and it was an easy decision to go to DCC, and now I overdesign stuff just because I can - like the Aurdino controlled program track switcher I'm designing - to switch my program track between PR3 (I might get an SPROG instead), Lokprogrammer, DC power pack for testing, and a 4th port that for now will be unused. All i REALLY need is a two pole rotary switch, but using an Arduino and some relays and a display to show the selected device seems like more fun.

                 --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Mark R. on Saturday, February 6, 2016 12:43 PM

rrinker

 I always wire parallel - and i don't do common rail to the track, either. While I DO have an EE degree, my model railroad experience started with HO before I was 3 years old, so I'm not sure how you would characterize my various experience levels. Though as a kid we never had a permanent layout, just one we set up every year from Thanksgiving to a little after New Year. The rest of the year my favorite toys were legos, Erector set, and a box full of batteries, wires, and switches - when I was 5 or 6, I found the train layout looking ready to at least run trains around, but when it got to the back, the train stopped. I crawled around and found the insulated joiners my Dad installed, and the unconnected feeder wires. Connected them up and had trains running when he got home.

 So, am I a train guy with lots of electronic experience (keep in mind that despite my degree, I only briefly worked as an EE before getting pretty much 100% into computer work, which remains my day job - electronics is just a hobby for me now) or am I an electronics guy who happened to get into trains? While I was going to all the local tourist railroads from a young age (I have some old slides I scanned I'll have to post in the prototype section), the bulk of my prototype knowledge has been accumulated since well after college. Hmm, does it even matter? Big Smile I like triand and I like electronics, and it was an easy decision to go to DCC, and now I overdesign stuff just because I can - like the Aurdino controlled program track switcher I'm designing - to switch my program track between PR3 (I might get an SPROG instead), Lokprogrammer, DC power pack for testing, and a 4th port that for now will be unused. All i REALLY need is a two pole rotary switch, but using an Arduino and some relays and a display to show the selected device seems like more fun.

                 --Randy

 

And that has what to do with wall-warts ? Confused

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by rrinker on Saturday, February 6, 2016 1:12 PM

 <reply removed, not worth it>

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by MisterBeasley on Sunday, February 7, 2016 10:43 AM

Y'know what?  You are better off going to Amazon or eBay and ordering a more hefty supply from some company in China for $5, and then go to Radio Shack and get a fuse holder and a package of fuses.

Your plan will leave you with a half-dozen tiny supplies, generally 1 amp or less, and if you don't fuse them you will experience "lighting creep" where you add one more bulb here and there, exceed the rating of the supply and burn it out.  Even if you don't toast one, you'll go to the hardware store and buy AC outlet strips to plug them into, and find that one of those strips costs more than that supply from China.

All of my layout lighting is standardized on 12 VDC.  Eventually, you'll discover that standardization works better than running one group of lights on 3 volts, another on 4.5 volts and so on.

It takes an iron man to play with a toy iron horse. 

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