LGB filament vs LED bulbs - PWM controller

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Trainbrain

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I am in the process of converting a LGB 2-6-6-2 to battery power. The battery power will be 12V Li-Ion on a PWM controller. I'm in a fork in the road between these two options:

1. Continue using LGB filament bulbs and powering it from the PWM Motor +/- terminals. I should buy new 18V or 24V filament bulbs as the ones I have are 5V only and I believe the voltage was regulated by the analog circuit board before. All the circuit boards are removed now. With this method, my concern is that the bulb won't be bright enough as my PWM controller speed will be mostly set at 6V-10V (12V max). And do the lights take away power to the motor?

2. Create a new circuit just for the LED lights. I can hook up 2 AAs/CR2032 (3V) battery and an on/off switch. The lights will be turned on/off manually. This way the 12V Li-Ion will be completely dedicated to the motors. The downside of this is that it takes an extra step to turn on/off the lights and there's an additional set of batteries/circuit to contain.

Looking forward to hearing your thoughts.
 
Bulbs will take a minute amount of power, compared to the motors..

Bulbs will vary in brightness, as you alter the speed, if you wire them across the motor.

LEDs will be 'full brightness' immediately you apply motor-power, but you MUST protect them with a series resistor.

What radio system are you going to use?
Those designed for 'trains' usually have directional light outputs.
Those that don't, you could use a spare channel, and a servo-switch.

PhilP
 
PhilP PhilP I am using one of these PWM controllers which only has 4 terminals, the Motor +/- and Power +/-.
 

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Trainbrain said:
PhilP PhilP I am using one of these PWM controllers which only has 4 terminals, the Motor +/- and Power +/-.
Click to expand...
Gotcha..
So I would suggest you go to LEDs, and wire them across the motor..

There are online calculators, to size the resistors, but something around 1k and half a watt, should do the trick.

PhilP
 
Loco said:
You can also go a little higher on the resistance value to have a dimmer light from the LED.
Trainbrain said:
I am in the process of converting a LGB 2-6-6-2 to battery power. The battery power will be 12V Li-Ion on a PWM controller. I'm in a fork in the road between these two options:

1. Continue using LGB filament bulbs and powering it from the PWM Motor +/- terminals. I should buy new 18V or 24V filament bulbs as the ones I have are 5V only and I believe the voltage was regulated by the analog circuit board before. All the circuit boards are removed now. With this method, my concern is that the bulb won't be bright enough as my PWM controller speed will be mostly set at 6V-10V (12V max). And do the lights take away power to the motor?

2. Create a new circuit just for the LED lights. I can hook up 2 AAs/CR2032 (3V) battery and an on/off switch. The lights will be turned on/off manually. This way the 12V Li-Ion will be completely dedicated to the motors. The downside of this is that it takes an extra step to turn on/off the lights and there's an additional set of batteries/circuit to contain.

Looking forward to hearing your thoughts.
Click to expand...

Here is an online LED calculator which is easy to use and shows the result with graphics:

ledcalculator.net

LED Calculator - Current limiting resistor calculator for LED arrays

This LED calculator will help you calculate the resistor values you will need when designing a series/parallel LED array circuit.
ledcalculator.net ledcalculator.net
Click to expand...
I just finished converting my 2-6+6-2 to Blunami. I installed 16 lith ion cells in series/parallel in the tender. Gives me about 16 volts when charged. works fantastic! Ok now to the question. The tender backup light is 36 ohms. needing twelve volts. the head light on the oter hand is only 17 ohms requiring less then 12v. I fed the backup off the blunami output. The front i used a 220 ohm resistor to reduce the 12v to the required +or - 7v. The smoke is only 7 ohms and I used a 10 + 10 + a 4.7 ohm for about 24.7 ohms to reduce to the needed voltage. I used two watt resistor through out. I did wire up a red led for a firebox light using a 1000 ohm resistor.
By the way I learned you must run the wires over the top of the board not in the lower boiler. that engine is a challenge to do. To sum up I went with the LGB bulbs and they worked great!
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