Thoroughly Confused about Woodland Scenics Just Plug and alternative lighting option compatiblity?

The Just Plug hub output is 16VDC, but each port is current limited to only 30ma.  This will only be enough for 2 or 3 of the 3 LED segments of your light strip.  Whether the dwarf signal will work depends on its current draw.

Better options would be a 12vDC "wall wart" power supply, or an AC transformer 14v accessory output with GRJ LED lighting regulator from Hennings Trains, or use an AC transformer 14v accessory output along with a bridge rectifier and a buck-boost 12vDC module from eBay as outlined by Stan.

Here are FAQs for the Just Plug system.

Bob

RR Doc:  Just what the "Doc-Tor" ordered.  I read the information from Woodland Scenics, and was a little disappointed about the port ratings regarding 30 ma, which is insufficient for a 15" locomotive shed. However, the references you gave regarding supplemental transformers or regulators is very helpful and greatly appreciated.  Thanks a bunch!

These are the block targets

Specification:

• Brand:Evemodel.
• Size: Please see the picture.
• Scale: 1:32~1:50,Suitable for O scale.
• Operating Voltage: 3V, AC or DC Compatible.
• Operating Current: 20mA.
• Materiallastic

These are the Light Strips:

Probably will need resistors to install.

FYI  

https://www.youtube.com/watch?v=CZgqGTxL9cA

Back to Physics 101 in college -- Egad!!! -- 46 yrs ago

For the block targets, you can wire 7 red LEDs (2.1 V x 7 = 14.7V) in series or 6 green LEDs (2.6V x 6 = 15.6V) in series.  The total voltage drop cannot exceed the 16V supply voltage.  

The Just Plug ports will supply 30ma which may be too bright, so you could try adding a resistor in series. Start with 22 ohm 1/8 watt and increase or decrease value (2 resistors in series will give you 44 ohms, 2 resistors in parallel will give 11 ohms, 3 in parallel will give you 7 ohms, etc.).

If each LED is to be individually turned on and off, you are much more limited.  Here you will wire each LED in parallel and you can only power 2 LEDs off each port.  They will be a little dimmer since each will only receive 15ma. Parallel LEDs must match ie., 2 reds or 2 greens on a given port.

Your light strips have 2 parallel sets of 3 warm white LEDs in series with a resistor.  You can try connecting them to the Just Plug port.  I am not sure if they will light (because of the resistors) but there is no harm in trying.  If it works, you would probably only be able to light 1 strip from each port.

As noted in my first post, you are better off using an alternate power supply and use the Just Plug system with its intended lights.  For the light strips, use a 12 VDC 2A power supply ($10 on Amazon).  It will light 66 of your LED strips.  

For the block targets, assuming you need to control the LEDs individually, use a 3 VDC 1A wall wart ($5-6 on Amazon).  Each Red LED will be connected in series with a 47 Ohm 1/8 watt resistor, and each Green LED will be connected in series with a 22 Ohm 1/8 watt resistor.  The 3V 1A power supply will light 50 LEDs.

Bob

@RRDOC posted:

For the block targets, you can wire 7 red LEDs (2.1 V x 7 = 14.7V) in series or 6 green LEDs (2.6V x 6 = 15.6V) in series.  The total voltage drop cannot exceed the 16V supply voltage.  

The Just Plug ports will supply 30ma which may be too bright, so you could try adding a resistor in series. Start with 22 ohm 1/8 watt and increase or decrease value (2 resistors in series will give you 44 ohms, 2 resistors in parallel will give 11 ohms, 3 in parallel will give you 7 ohms, etc.).

If each LED is to be individually turned on and off, you are much more limited.  Here you will wire each LED in parallel and you can only power 2 LEDs off each port.  They will be a little dimmer since each will only receive 15ma. Parallel LEDs must match ie., 2 reds or 2 greens on a given port.

Your light strips have 2 parallel sets of 3 warm white LEDs in series with a resistor.  You can try connecting them to the Just Plug port.  I am not sure if they will light (because of the resistors) but there is no harm in trying.  If it works, you would probably only be able to light 1 strip from each port.

As noted in my first post, you are better off using an alternate power supply and use the Just Plug system with its intended lights.  For the light strips, use a 12 VDC 2A power supply ($10 on Amazon).  It will light 66 of your LED strips.  

For the block targets, assuming you need to control the LEDs individually, use a 3 VDC 1A wall wart ($5-6 on Amazon).  Each Red LED will be connected in series with a 47 Ohm 1/8 watt resistor, and each Green LED will be connected in series with a 22 Ohm 1/8 watt resistor.  The 3V 1A power supply will light 50 LEDs.

Bob

Greatly appreciated the help.  Thank you.

I'll probably get a separate power supply for the block targets... Tristan