Battery conversions and LEDs

[CoggesRailway]

Hi All,

Please humour me. I HAVE searched and read the relevant threads on the forum and I am afraid I need even simpler guidance. For example I don't understand the symbols in the circuit diagrams or (I am embarrassed to say) the accompanying maths etc.

So far my battery conversions have been to wire a G Scale Graphics speed controller to a battery and directly to the motor. This works fine. But I lose the lights.

How, very simply, can I have a similar set up AND lights? What is the reason for the resistors and what do they do? Can I buy a circuit built with a super bright LED. I bought some super bright 12v LED at Maplin and there is nothing bright about them at 12v!

So If someone wants to attempt a very basic, assume no knowledge explanation I would be very grateful.

Ian

 

[Rhinochugger]

I used 3v LED with resistors - but they're yellow LEDs so not very bright.

Having used a very simple set up, I can only think that by using the 3v LEDs in this way, they happily light up whatever current is going through the controller to the battery.

I also used the simple method of wiring two LEDs in parallel with their tails reversed so that they were automatically directional.

Battery pack was 7.2v and is now 12v - 2300 mAh
Speed controller is Cambrian (couldn't get the IP one to work)
Motor was 3 pole IP Engineering but is now 5 pole Bachmann from an early battery powered big hauler (plastic wheels)

None of these changes to the equipment have affected the lights - nor did the loco's leap from the highest point of the elevated track to a paving slab affect the LEDs or their operation

See if you can PM Neil Robinson - he's the circuit guru

 

[Del Tapparo]

Hi Ian - Which G-Scale Graphics controller do you have? I would be glad to help you.

The Enhanced Critter Control does have directional lighting outputs. It even has a current source to drive LEDs so don't have to use a resistor.

If you have the Basic Critter Control, or the Simple Critter Control, there are two easy ways to power your lighting circuits: 1: Connect the controls motor output to the lighting circuitry, just like it was with the track power. The lights will then dim when motor speed is low or stopped, but they will still function just like they did on track power. 2: Connect the lights to the switched battery power. Whenever you turn on your battery power, the lights are on at a constant brightness. If you are using incandescent lamps, they must be of the proper voltage (12V lights used with a12-14V battery for example). If you are using LEDs, each LED must have a resistor in series with it to limit the current. Usually a 1K (1000 ohm) resistor will do the job.

Feel free to reply here or contact me directly. http://1stclass.mylargescale.com/DelTapparo/gscalegraphics_1_004.htm < Link To Contact info

 

[nicebutdim]

I've used one of these http://1stclass.mylargescale.com/DelTapparo/gscalegraphics_1_019.htm < Link To http://1stclass.mylargesc...calegraphics_1_019.htm wired to a small relay that switches the leds for the direction. This then works so that the leds are permanently lit for the direction that the locomotive will be heading even when stationary.

 

[whatlep]

Ian - the easiest way to use LEDs for lights is to get them from eBay pre-wired with the correct resistor for the voltage you will be using. That's not necessarily the same as the battery voltage, since you may not be running at (say) 12 volts all the time. For example, the battery locos of mine which you've seen are normally running at around 6-9 volts. Have a play with your loco and check using a voltmeter what maximum voltage is being drawn from the battery. Obviously if you use the method suggested in an earlier post of having the lights manually controlled through a switch then you can go with the battery voltage.

Armed with that info, search on eBay for "prewired LED <voltage> <colour>". For example "prewired LED 12 white". There are umpteen for sale at any given time.

 

[CoggesRailway]

Thanks chaps

 

[CoggesRailway]

OK another question. I have spotted a promising super bright white pre wired 12v LED pack on ebay as per Peter's suggestion. The trains I am thinking of have 14.4v batteries that overcharge to about 16v . If I manually attached these direct to the battery with a switch will this fry them - or is the purpose of the resistor to protect the LED?

 

[Gizzy]

OK another question. I have spotted a promising super bright white pre wired 12v LED pack on ebay as per Peter's suggestion. The trains I am thinking of have 14.4v batteries that overcharge to about 16v . If I manually attached these direct to the battery with a switch will this fry them - or is the purpose of the resistor to protect the LED?

The resistor limits the current flow through the LED. You should find that these run okay from your 14.4 V battery, as the motor (load) will reduce this somewhat.

A single LED uses 0.6 Volts in the forward conducting direction, producing light. Your pack may be made of more than one led, so may drop more volts. Without the technical details, it is difficult to say.

If connected the wrong way around, it won't work, as it works like a one way valve, so swap your connections around if there is no light emitted. If the LED doesn't work either way, then you've blown it....

 

[Rhinochugger]

I have at last found the circuit diagram that I made for the blue and yellow low flying diesel.

This is not a traditional circuit diagram, it is drawn so that I could solder the circuit onto PC board. Every green line is a line of copper strip on the PC board. Where a wire is soldered to the PC board, ti dips towards it at 45 degrees.

It may not help - but it worked for me

It was the original circuit and does not show a fuse - should be close to the battery on the +ve side.

 

[whatlep]

OK another question. I have spotted a promising super bright white pre wired 12v LED pack on ebay as per Peter's suggestion. The trains I am thinking of have 14.4v batteries that overcharge to about 16v . If I manually attached these direct to the battery with a switch will this fry them - or is the purpose of the resistor to protect the LED?

On 14.4 volts, a 12volt prewired LED should be OK. There is some tolerance in the resistor amounts as it's not an exact science. On 16 volts it depends on how long the battery stays that high for and how tolerant the LED is of excess voltage. Chances are you'll get away with it. Try with one LEd first. If it fries, you'll know to either add mroe resistance or keep the lights off until the voltage drops a bit. Simples!

 

[Rhinochugger]

Ian, a quick thought.

LEDs are never as bright as bulbs. When they are described as bright white, that's referring to the colour, not the brilliance (as in candle power or lux). A few years ago you could not get a white LED, that's why the ones on my blue and yellow disesl are yellow - that's as good as you could get for reasonable money.

Where LEDs are used to replace bulbs and give equivalent brilliance, they are used in clusters.

So, if you're looking for a loco headlight that will cast a beam of light down the track, use a bulb. If you want a headlight that will tell you where your loco is in the dark, an LED will be fine

My track powered locos have bulbs, so far the only battery powered one has LEDs, not sure what is going to happen with the santa special that's due to arrive

 

[Doug]

LEDs can be brighter than bulbs, it depends on which one you use. You need to look at the light output on the data sheets - look for Lux, Lumens or Candela as a measure of light output.

Just bought a torch with one LED chip - its brighter than car headlamps

 

[CoggesRailway]

I definately want a light to shine down the track! Thanks so much everyone who has contributed to this thread.

 

[Neil Robinson]

LEDs can be brighter than bulbs, it depends on which one you use. You need to look at the light output on the data sheets - look for Lux, Lumens or Candela as a measure of light output.

Just bought a torch with one LED chip - its brighter than car headlamps

Whilst examining the data sheets take note of the viewing angle. Narrow angle ones often have high light outputs but are only effective over a narrow range. Great for bright headlights but for coach interior lighting wider angle, lower light output ones are often better.

 

[Madman]

Ian, a quick thought.

LEDs are never as bright as bulbs. When they are described as bright white, that's referring to the colour, not the brilliance (as in candle power or lux). A few years ago you could not get a white LED, that's why the ones on my blue and yellow disesl are yellow - that's as good as you could get for reasonable money.

Where LEDs are used to replace bulbs and give equivalent brilliance, they are used in clusters.

So, if you're looking for a loco headlight that will cast a beam of light down the track, use a bulb. If you want a headlight that will tell you where your loco is in the dark, an LED will be fine

My track powered locos have bulbs, so far the only battery powered one has LEDs, not sure what is going to happen with the santa special that's due to arrive

I respectfully beg to disagree with you. Take a look at this video. I converted one of my 2090 diesels to white LEDs. And while you may reply with a, you're looking at them head on, believe me, in the dark they definitely cast a beam of light down the track.

http://youtu.be/gRosjkSRxHs

 

[CoggesRailway]

Yes Dan I agree - indeed I have LED mini torch with one LED which is fully functional as a torch. I think the bulbs being brighter has been the case for many years but things have changed.... By the way I like your little yellow critter with smoke and sound!

 

[Rhinochugger]

Ian, a quick thought.

LEDs are never as bright as bulbs. When they are described as bright white, that's referring to the colour, not the brilliance (as in candle power or lux). A few years ago you could not get a white LED, that's why the ones on my blue and yellow disesl are yellow - that's as good as you could get for reasonable money.

Where LEDs are used to replace bulbs and give equivalent brilliance, they are used in clusters.

So, if you're looking for a loco headlight that will cast a beam of light down the track, use a bulb. If you want a headlight that will tell you where your loco is in the dark, an LED will be fine

My track powered locos have bulbs, so far the only battery powered one has LEDs, not sure what is going to happen with the santa special that's due to arrive

I respectfully beg to disagree with you. Take a look at this video. I converted one of my 2090 diesels to white LEDs. And while you may reply with a, you're looking at them head on, believe me, in the dark they definitely cast a beam of light down the track.

http://youtu.be/gRosjkSRxHs

Technology moves on apace - faster than me

 

[Gizzy]

Take a look at this video. I converted one of my 2090 diesels to white LEDs. And while you may reply with a, you're looking at them head on, believe me, in the dark they definitely cast a beam of light down the track.

http://youtu.be/gRosjkSRxHs

What sound card is that Dan please?

 

[Madman]

Ian, a quick thought.

LEDs are never as bright as bulbs. When they are described as bright white, that's referring to the colour, not the brilliance (as in candle power or lux). A few years ago you could not get a white LED, that's why the ones on my blue and yellow disesl are yellow - that's as good as you could get for reasonable money.

Where LEDs are used to replace bulbs and give equivalent brilliance, they are used in clusters.

So, if you're looking for a loco headlight that will cast a beam of light down the track, use a bulb. If you want a headlight that will tell you where your loco is in the dark, an LED will be fine

My track powered locos have bulbs, so far the only battery powered one has LEDs, not sure what is going to happen with the santa special that's due to arrive

I respectfully beg to disagree with you. Take a look at this video. I converted one of my 2090 diesels to white LEDs. And while you may reply with a, you're looking at them head on, believe me, in the dark they definitely cast a beam of light down the track.

http://youtu.be/gRosjkSRxHs

Technology moves on apace - faster than me

Don't feel alone. I still use a flip style, cellullar telephone

 

[whatlep]

Don't feel alone. I still use a flip style, cellullar telephone

Why can't I find one of those with a dial?