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Discussion Starter #1
I'm looking at some lampposts on Ebay and they are LEDS on 3v. They come with resistors. My question is: Can I wire these together (with resistors on each lamp) and connect them to a TYCO AC/DC power pack. Should I, could I attach the lamps to the Accessory posts (12-20v) on the Tyco without buring out the lights? Don't the resistors prevent this? I don't pretend to know much about this whole resistor thing and want to know more. I really like these lamps but I want to know what I'm doing 1st.
PS The Woodland Scenics plug n play really adds up $ wise especially when you want a bunch of lights.
Thank you as always
 

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You could give us a link to the particular offering on ebay so we could read up. My brother bought me these which came with a resistor. I powered them from a plug in the wall (wall-wart) 12VDC converter which was from a Netgear router. I also have some incandescant bulbs on the same feed. Most likely the ebay ofering is 3VDC LED's and the included resistor makes them suitable for 12VDC, one resistor per bulb.

539926
539928
 

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Each LED needs a resistor in series with the LED [ +resistor_____LED_-] Then you can supply 12 volt DC to each. I would attach the resistor to the same side on each LED so it's easier to see which is Positive connection and which is the negative connection. It makes no difference which side you pick, just be consistent. At 12v I would use a atleast a 1K resistor (1/4 watt types are fine). You mentioned that they came with resistors, what is the value? A close up picture will do if you can't decode the color rings, or better still a reading from an Ohm meter. By the way full brightness at 12 would use a 450 Ohm resistor, but I think that will be way to bright, hence the use of a 1K (1000 Ohm) resistor. If you want to control the dimming then there are other ways to to do this but the wiring to the LED's would be the same.
 

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Discussion Starter #4
I'm looking at some lampposts on Ebay and they are LEDS on 3v. They come with resistors. My question is: Can I wire these together (with resistors on each lamp) and connect them to a TYCO AC/DC power pack. Should I, could I attach the lamps to the Accessory posts (12-20v) on the Tyco without buring out the lights? Don't the resistors prevent this? I don't pretend to know much about this whole resistor thing and want to know more. I really like these lamps but I want to know what I'm doing 1st.
PS The Woodland Scenics plug n play really adds up $ wise especially when you want a bunch of lights.
Thank you as always
Hi Dennis
Thanks...those are the same lamps I'm looking at
 

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Discussion Starter #5
Each LED needs a resistor in series with the LED [ +resistor_____LED_-] Then you can supply 12 volt DC to each. I would attach the resistor to the same side on each LED so it's easier to see which is Positive connection and which is the negative connection. It makes no difference which side you pick, just be consistent. At 12v I would use a atleast a 1K resistor (1/4 watt types are fine). You mentioned that they came with resistors, what is the value? A close up picture will do if you can't decode the color rings, or better still a reading from an Ohm meter. By the way full brightness at 12 would use a 450 Ohm resistor, but I think that will be way to bright, hence the use of a 1K (1000 Ohm) resistor. If you want to control the dimming then there are other ways to to do this but the wiring to the LED's would be the same.
Hi Lemonhawk...thanks
To control the dimming, could I use the train control wheel instead of the accessory terminal?
You could give us a link to the particular offering on ebay so we could read up. My brother bought me these which came with a resistor. I powered them from a plug in the wall (wall-wart) 12VDC converter which was from a Netgear router. I also have some incandescant bulbs on the same feed. Most likely the ebay ofering is 3VDC LED's and the included resistor makes them suitable for 12VDC, one resistor per bulb.

View attachment 539926 View attachment 539928
 

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I'm looking at some lampposts on Ebay and they are LEDS on 3v. They come with resistors. My question is: Can I wire these together (with resistors on each lamp) and connect them to a TYCO AC/DC power pack. Should I, could I attach the lamps to the Accessory posts (12-20v) on the Tyco without buring out the lights? Don't the resistors prevent this? I don't pretend to know much about this whole resistor thing and want to know more. I really like these lamps but I want to know what I'm doing 1st.
PS The Woodland Scenics plug n play really adds up $ wise especially when you want a bunch of lights.
Thank you as always
beepjuice;

Do NOT connect these lampposts, or any other LED, to the "accessories" terminals of a power pack. Typically the accessories terminals output AC (Alternating Current) which can destroy the LEDs. Unlike incandescent lamps, the coils of twin-coil switch machines, and a host of other electrical devices, LEDs (Light Emitting Diodes) do not run on either AC or DC. They are designed to run on DC only. The resistors included are intended to limit the amount of current that passes through the LEDs. That amount of current is affected by the amount of DC voltage applied to the LED and resistor. The "DC/track" output terminals of a power pack may have up to 12-18 volts of DC on them , when the speed control is turned all the way up. That may be too much for your LED and resistor, so turn the speed control all the way down to zero before doing the following test.

To test things, I suggest you try another LED, rather than risking one of your lampposts. Connect that "test" LED, and a resistor of the same resistance as the one on a lamppost, to the "DC" or "Track" terminals of your power pack. Then turn the knob up to about one quarter power. The LED will either light, or not, depending on which way it's attached to the terminals. If it didn't light then turn the speed knob back down to zero, and reverse the wires feeding the LED/resistor combination. In other words, put whatever wire was on terminal 1 onto terminal 2 and vice/versa. Try turning the knob back up to one quarter power. The LED should now light.

To do this, and many other electrical jobs on your railroad, properly, and easily, you really should use a multimeter. If you don't have one, then you can get one from Harbor Freight www.harborfreight.com for only $5. (see photo)
It's a basic meter, but it does everything you'll need to do on the railroad, and it comes with directions.
Two of the things you will be able to use your new meter for right away, are to measure the resistance of one of the lamppost resistors, in order to match your "test resistor" to it, and to measure the minimum DC voltage coming from the power pack's DC terminals, that will light your LED. You can increase the voltage SLIGHTLY to make the LED glow brighter, but too much voltage may burn it out.

{Technical stuff} .........Resistors are also marked with color bands to indicate their resistance value in electrical units called "Ohms."
So, if you get a test resistor that has exactly the same color bands, in the same order, as the lamppost resistors, then it should be the same resistance that they are.
The colors work like this to show the number of Ohms of resistance a particular resistor has;
black = 0, brown = 1, red = 2, orange = 3, yellow = 4, green = 5, blue = 6, violet = 7, gray = 8, & white = 9.

Reading left-to-right from the end of the resistor with the most space between the color band, and the end of the resistor, the first two colors are normal numbers. For example, violet gray would mean 68 The third band indicates the number of zeros that follow those first two numbers. For example, violet blue black would mean 68 with no zeros, or sixty-eight Ohms. (By the way, 68 Ohms is a good resistance to operate an LED on 12 volts DC) However, violet blue orange would mean 68 followed by 000, or sixty-eight thousand Ohms! With that much resistance, the LED would not light at all. Resistors have a forth band that will be gold, silver, or blank. Some even have a fifth band. You can ignore the fourth and fifth bands. They just indicate the % of accuracy of the stated value, and for your purposes, that doesn't matter at all.
Now do you see why it's easier to just measure the resistance with a meter?

Good luck & Have fun;

Traction Fan 😊
 

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Discussion Starter #7
beepjuice;

Do NOT connect these lampposts, or any other LED, to the "accessories" terminals of a power pack. Typically the accessories terminals output AC (Alternating Current) which can destroy the LEDs. Unlike incandescent lamps, the coils of twin-coil switch machines, and a host of other electrical devices, LEDs (Light Emitting Diodes) do not run on either AC or DC. They are designed to run on DC only. The resistors included are intended to limit the amount of current that passes through the LEDs. That amount of current is affected by the amount of DC voltage applied to the LED and resistor. The "DC/track" output terminals of a power pack may have up to 12-18 volts of DC on them , when the speed control is turned all the way up. That may be too much for your LED and resistor, so turn the speed control all the way down to zero before doing the following test.

To test things, I suggest you try another LED, rather than risking one of your lampposts. Connect that "test" LED, and a resistor of the same resistance as the one on a lamppost, to the "DC" or "Track" terminals of your power pack. Then turn the knob up to about one quarter power. The LED will either light, or not, depending on which way it's attached to the terminals. If it didn't light then turn the speed knob back down to zero, and reverse the wires feeding the LED/resistor combination. In other words, put whatever wire was on terminal 1 onto terminal 2 and vice/versa. Try turning the knob back up to one quarter power. The LED should now light.

To do this, and many other electrical jobs on your railroad, properly, and easily, you really should use a multimeter. If you don't have one, then you can get one from Harbor Freight www.harborfreight.com for only $5. (see photo)
It's a basic meter, but it does everything you'll need to do on the railroad, and it comes with directions.
Two of the things you will be able to use your new meter for right away, are to measure the resistance of one of the lamppost resistors, in order to match your "test resistor" to it, and to measure the minimum DC voltage coming from the power pack's DC terminals, that will light your LED. You can increase the voltage SLIGHTLY to make the LED glow brighter, but too much voltage may burn it out.

{Technical stuff} .........Resistors are also marked with color bands to indicate their resistance value in electrical units called "Ohms."
So, if you get a test resistor that has exactly the same color bands, in the same order, as the lamppost resistors, then it should be the same resistance that they are.
The colors work like this to show the number of Ohms of resistance a particular resistor has;
black = 0, brown = 1, red = 2, orange = 3, yellow = 4, green = 5, blue = 6, violet = 7, gray = 8, & white = 9.

Reading left-to-right from the end of the resistor with the most space between the color band, and the end of the resistor, the first two colors are normal numbers. For example, violet gray would mean 68 The third band indicates the number of zeros that follow those first two numbers. For example, violet blue black would mean 68 with no zeros, or sixty-eight Ohms. (By the way, 68 Ohms is a good resistance to operate an LED on 12 volts DC) However, violet blue orange would mean 68 followed by 000, or sixty-eight thousand Ohms! With that much resistance, the LED would not light at all. Resistors have a forth band that will be gold, silver, or blank. Some even have a fifth band. You can ignore the fourth and fifth bands. They just indicate the % of accuracy of the stated value, and for your purposes, that doesn't matter at all.
Now do you see why it's easier to just measure the resistance with a meter?

Good luck & Have fun;

Traction Fan 😊
Thank you Traction Fan for the quick lesson! Good to know I won't use the accessory output. The lamps come with the proper resistor so I should be fine. I just ordered them so I'll post the reuults later.
Thanks, again!
 

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If you DO want to use the AC accessory terminals, we can help you design a AC-DC converter/voltage regulator to connect your lights. I use the AC terminals to run my DC turntable with a converter, after all, why let the accessory terminals go to waste.
 

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Discussion Starter #9
If you DO want to use the AC accessory terminals, we can help you design a AC-DC converter/voltage regulator to connect your lights. I use the AC terminals to run my DC turntable with a converter, after all, why let the accessory terminals go to waste.
Thanks, Dennis but I'll just use the DC track terminals. Simple fix for a simple guy! I run the trains with a Digitrax Zephyr and I have a few of these old Tyco, Bachmann power packs I can use for the lights.
Thanks for the help
 

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Nearly all of the street lights I have seen use LEDs that can handle a maximum of 20 milli-amps (mA). I usually wire mine to run at about 10-15 mA in an attempt to maximize life. Even at very low current levels they put out a lot of light. You can use just about any DC voltage if you remember this formula R (resistance) = (DC voltage - LED voltage drop) divided by Current). Most LEDs have a 1 to 2 volt voltage drop. It varies by color of LED. So here's an example For 12 VDC supply and 10 mA current, Resistance = (12-1) / (0.010) R=1100 ohms Using a 1000 ohm resistor would result in 11 mA current which is fine.
 

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beepjuice;

Do NOT connect these lampposts, or any other LED, to the "accessories" terminals of a power pack. Typically the accessories terminals output AC (Alternating Current) which can destroy the LEDs. Unlike incandescent lamps, the coils of twin-coil switch machines, and a host of other electrical devices, LEDs (Light Emitting Diodes) do not run on either AC or DC. They are designed to run on DC only. The resistors included are intended to limit the amount of current that passes through the LEDs. That amount of current is affected by the amount of DC voltage applied to the LED and resistor. The "DC/track" output terminals of a power pack may have up to 12-18 volts of DC on them , when the speed control is turned all the way up. That may be too much for your LED and resistor, so turn the speed control all the way down to zero before doing the following test.

To test things, I suggest you try another LED, rather than risking one of your lampposts. Connect that "test" LED, and a resistor of the same resistance as the one on a lamppost, to the "DC" or "Track" terminals of your power pack. Then turn the knob up to about one quarter power. The LED will either light, or not, depending on which way it's attached to the terminals. If it didn't light then turn the speed knob back down to zero, and reverse the wires feeding the LED/resistor combination. In other words, put whatever wire was on terminal 1 onto terminal 2 and vice/versa. Try turning the knob back up to one quarter power. The LED should now light.

To do this, and many other electrical jobs on your railroad, properly, and easily, you really should use a multimeter. If you don't have one, then you can get one from Harbor Freight www.harborfreight.com for only $5. (see photo)
It's a basic meter, but it does everything you'll need to do on the railroad, and it comes with directions.
Two of the things you will be able to use your new meter for right away, are to measure the resistance of one of the lamppost resistors, in order to match your "test resistor" to it, and to measure the minimum DC voltage coming from the power pack's DC terminals, that will light your LED. You can increase the voltage SLIGHTLY to make the LED glow brighter, but too much voltage may burn it out.

{Technical stuff} .........Resistors are also marked with color bands to indicate their resistance value in electrical units called "Ohms."
So, if you get a test resistor that has exactly the same color bands, in the same order, as the lamppost resistors, then it should be the same resistance that they are.
The colors work like this to show the number of Ohms of resistance a particular resistor has;
black = 0, brown = 1, red = 2, orange = 3, yellow = 4, green = 5, blue = 6, violet = 7, gray = 8, & white = 9.

Reading left-to-right from the end of the resistor with the most space between the color band, and the end of the resistor, the first two colors are normal numbers. For example, violet gray would mean 68 The third band indicates the number of zeros that follow those first two numbers. For example, violet blue black would mean 68 with no zeros, or sixty-eight Ohms. (By the way, 68 Ohms is a good resistance to operate an LED on 12 volts DC) However, violet blue orange would mean 68 followed by 000, or sixty-eight thousand Ohms! With that much resistance, the LED would not light at all. Resistors have a forth band that will be gold, silver, or blank. Some even have a fifth band. You can ignore the fourth and fifth bands. They just indicate the % of accuracy of the stated value, and for your purposes, that doesn't matter at all.
Now do you see why it's easier to just measure the resistance with a meter?

Good luck & Have fun;

Traction Fan 😊

Resistor codes are read left to right with the color band NEAREST the end. Not the other way around as stated.
Violet/grey =78. Not 68.
Violet/blue/orange would be 76 followed by 000. Again, not 68.

"If one is to be meticulous at explanations/directions, one should also be correct."

G'day
 

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I bought about 100 3 volt lamps and was not about to add a resistor to each and every one so I also bought a couple of 3 volt power supplies to power them. I think they were $5.00 each free shipping.

barrel_factory_1.jpg
truck_yard_lights.jpg
 

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Discussion Starter #13
I bought about 100 3 volt lamps and was not about to add a resistor to each and every one so I also bought a couple of 3 volt power supplies to power them. I think they were $5.00 each free shipping.

View attachment 540049 View attachment 540050
Hi "T"
I saw the power supply and am wondering how you connect the lamps to the connector on the PS. I will use a buss bar and only have 2 wires to the connector so do you cut off the connector and use those wires?
Thanks
 

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Hi "T"
I saw the power supply and am wondering how you connect the lamps to the connector on the PS. I will use a buss bar and only have 2 wires to the connector so do you cut off the connector and use those wires?
Thanks

Just about any low voltage wall wart type power supply will have a connector designed
to plug into some device...to use it on a layout, just cut off the connector and connect
the wires to your bus, barrier strip or whatever you are using to power the lights or
accessories.

Note: If the wall wart has DC output, determine which wire is positive so that can
be used with LEDs. A multimeter set to DC is the best way to determine this.

Don
 

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Discussion Starter #15
Just about any low voltage wall wart type power supply will have a connector designed
to plug into some device...to use it on a layout, just cut off the connector and connect
the wires to your bus, barrier strip or whatever you are using to power the lights or
accessories.

Note: If the wall wart has DC output, determine which wire is positive so that can
be used with LEDs. A multimeter set to DC is the best way to determine this.

Don
Perfect...........Thanks, Don!
 

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Gunrunner John says to always use a resistor in series, it prevents a startup or other transient from wiping out your LED's. Also at 3v they are probably way to bright and will have reduced life.
 

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Resistor codes are read left to right with the color band NEAREST the end. Not the other way around as stated.
Violet/grey =78. Not 68.
Violet/blue/orange would be 76 followed by 000. Again, not 68.

"If one is to be meticulous at explanations/directions, one should also be correct."
,
G'day
Your information on resistors is correct. Mine was wrong. That said, your response would have been a lot less pretentious and insulting, if you had left off that last sentence. "If one is" blaa blaa. What I put in my posts, and how long they are is my business, not yours! By the way, While there were several errors in this particular response of mine (which you corrected) I have several thousand posts with a lot of correct information in them. I really don't appreciate some guy with less than a hundred posts telling me how "One" (meaning me) should do it.
Traction Fan
 

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Kilowatt;

Your information on resistors is correct. Mine was wrong. That said, your response would have been a lot nicer, if you had left off that last pretentious and insulting sentence. "If one is" blaa blaa.

,When I send something with errors in it, I expect to be corrected on the errors, and that part's OK, even helpful at times. However, how long, and detailed, my response may be is my business, not yours!
By the way, While there were indeed several errors in this particular response of mine (which you corrected) I have several thousand posts with a lot of correct information in them. I really don't appreciate some relatively new guy, with barely over a hundred posts telling me how "One" (meaning me) should do it.

I'm also not the only person on this form that has ever sent something with errors in it. Some of the responses are so lacking in grammar or spelling, that they need a lot of interpretation just to be read at all. Neither I, nor the other members, jump all over the poor guy who posted, and tell him how it should be done.

We have new people joining who, quite understandably, don't know all the technical terms used in model railroading. Often they're apologetic about not knowing the lingo of this hobby, before they even get into it. Do I tell them they don't know what they're talking about, and exactly how they ought to say it? No, I certainly do not .
Instead I invested a lot of my time, and effort, to create a long list of model railroad terminology so that anyone could look up any term they were not familiar with. That document starts off by saying there is no reason for them to apologize for not knowing all the terminology in advance. I did not tell them "If one is to be considered a real model railroader, they should know all these terms in advance" That would be pretentious and insulting, So I won't do that.
I wish I could say the same for you.

Traction Fan
 

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Resistor Value Code
Blk 0
Brn 1
Red 2
Orn 3
Yel 4
Grn 5
Blu 6
Vio 7
Gry 8
Whi 9

Resistor Tolerance Code
None 20%
Silver 10%
Gold 5%
 
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