Updated album Car lighting keep alive cap #photo-notice


w4dccqa@groups.io Notification <noreply@...>
 

Don Weigt <dweigt47@...> updated the album Car lighting keep alive cap: Greg Harter's passenger car lighting board with added capacitor. Greg reports lighting is constant for more than five seconds after power is removed from the rails. One photo is of the car with DCC power on the rails, the other after about five seconds without power. Can you tell which is which? The lighting board is from Walthers. The wires to the capacitor can be thin, as typically used wiring decoders. lt is possible long passenger trains with multiple cars would cause a problem by briefly drawing too much current when power is applied. If that happened, one fix would be to put a ten to about twenty Ohm resistor in either capacitor lead. This would reduce "keep alive" time a bit, as well as add complexity. The total modification cost per car would still be under half a dollar if the parts were bought from most online sources.


george hohon3
 

Here's my solution for passenger car and caboose lighting on an HO scale DCC layout:
  • 1A 50V Bridge Rectifier
  • 270 Ohm 1/2 watt Resistor (for in-rush current protection)
  • 470 /35 W Capacitor  (just a bit larger than track power)
  • 4.7K Ohm 1/2 watt Resistor  (brightness control for LED lights)
  • LED light strip (3 LEDs minimum)
There are no apparent "in-rush" current problems.

Brightness might be too bright, requiring a higher rated resistor (dependent on strip LED).

Flicker free operation is perfect, as in, there is no flicker!

If you're interested in the details, photos and the wiring schematic, let me know.

George



From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of w4dccqa@groups.io Notification <noreply@groups.io>
Sent: Sunday, March 6, 2022 7:23 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 

Don Weigt <dweigt47@...> updated the album Car lighting keep alive cap: Greg Harter's passenger car lighting board with added capacitor. Greg reports lighting is constant for more than five seconds after power is removed from the rails. One photo is of the car with DCC power on the rails, the other after about five seconds without power. Can you tell which is which? The lighting board is from Walthers. The wires to the capacitor can be thin, as typically used wiring decoders. lt is possible long passenger trains with multiple cars would cause a problem by briefly drawing too much current when power is applied. If that happened, one fix would be to put a ten to about twenty Ohm resistor in either capacitor lead. This would reduce "keep alive" time a bit, as well as add complexity. The total modification cost per car would still be under half a dollar if the parts were bought from most online sources.


Robert Heroux
 

George -

I would be interested in the details etc.

Thanks

Bob







On Mar 9, 2022, at 20:58, george hohon3 <Hohon3@...> wrote:

Here's my solution for passenger car and caboose lighting on an HO scale DCC layout:
  • 1A 50V Bridge Rectifier
  • 270 Ohm 1/2 watt Resistor (for in-rush current protection)
  • 470 /35 W Capacitor  (just a bit larger than track power)
  • 4.7K Ohm 1/2 watt Resistor  (brightness control for LED lights)
  • LED light strip (3 LEDs minimum)
There are no apparent "in-rush" current problems.

Brightness might be too bright, requiring a higher rated resistor (dependent on strip LED).

Flicker free operation is perfect, as in, there is no flicker!

If you're interested in the details, photos and the wiring schematic, let me know.

George 



From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of w4dccqa@groups.io Notification <noreply@groups.io>
Sent: Sunday, March 6, 2022 7:23 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 
Don Weigt <dweigt47@...> updated the album Car lighting keep alive cap: Greg Harter's passenger car lighting board with added capacitor. Greg reports lighting is constant for more than five seconds after power is removed from the rails. One photo is of the car with DCC power on the rails, the other after about five seconds without power. Can you tell which is which? The lighting board is from Walthers. The wires to the capacitor can be thin, as typically used wiring decoders. lt is possible long passenger trains with multiple cars would cause a problem by briefly drawing too much current when power is applied. If that happened, one fix would be to put a ten to about twenty Ohm resistor in either capacitor lead. This would reduce "keep alive" time a bit, as well as add complexity. The total modification cost per car would still be under half a dollar if the parts were bought from most online sources.



Pete
 

George,
I would like to have the schematic too.
Thanks,
Pete


On Thu, Mar 10, 2022 at 4:42 AM, Robert Heroux
<rheroux@...> wrote:
George -

I would be interested in the details etc.

Thanks

Bob







On Mar 9, 2022, at 20:58, george hohon3 <Hohon3@...> wrote:

Here's my solution for passenger car and caboose lighting on an HO scale DCC layout:
  • 1A 50V Bridge Rectifier
  • 270 Ohm 1/2 watt Resistor (for in-rush current protection)
  • 470 /35 W Capacitor  (just a bit larger than track power)
  • 4.7K Ohm 1/2 watt Resistor  (brightness control for LED lights)
  • LED light strip (3 LEDs minimum)
There are no apparent "in-rush" current problems.

Brightness might be too bright, requiring a higher rated resistor (dependent on strip LED).

Flicker free operation is perfect, as in, there is no flicker!

If you're interested in the details, photos and the wiring schematic, let me know.

George 



From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of w4dccqa@groups.io Notification <noreply@groups.io>
Sent: Sunday, March 6, 2022 7:23 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 
Don Weigt <dweigt47@...> updated the album Car lighting keep alive cap: Greg Harter's passenger car lighting board with added capacitor. Greg reports lighting is constant for more than five seconds after power is removed from the rails. One photo is of the car with DCC power on the rails, the other after about five seconds without power. Can you tell which is which? The lighting board is from Walthers. The wires to the capacitor can be thin, as typically used wiring decoders. lt is possible long passenger trains with multiple cars would cause a problem by briefly drawing too much current when power is applied. If that happened, one fix would be to put a ten to about twenty Ohm resistor in either capacitor lead. This would reduce "keep alive" time a bit, as well as add complexity. The total modification cost per car would still be under half a dollar if the parts were bought from most online sources.



george hohon3
 

Pete, I tried the email address from your post and it failed to go through.  Do you have another one?


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Pete via groups.io <Kayakerpc@...>
Sent: Thursday, March 10, 2022 7:02 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 
George,
I would like to have the schematic too.
Thanks,
Pete


On Thu, Mar 10, 2022 at 4:42 AM, Robert Heroux
<rheroux@...> wrote:
George -

I would be interested in the details etc.

Thanks

Bob







On Mar 9, 2022, at 20:58, george hohon3 <Hohon3@...> wrote:

Here's my solution for passenger car and caboose lighting on an HO scale DCC layout:
  • 1A 50V Bridge Rectifier
  • 270 Ohm 1/2 watt Resistor (for in-rush current protection)
  • 470 /35 W Capacitor  (just a bit larger than track power)
  • 4.7K Ohm 1/2 watt Resistor  (brightness control for LED lights)
  • LED light strip (3 LEDs minimum)
There are no apparent "in-rush" current problems.

Brightness might be too bright, requiring a higher rated resistor (dependent on strip LED).

Flicker free operation is perfect, as in, there is no flicker!

If you're interested in the details, photos and the wiring schematic, let me know.

George 



From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of w4dccqa@groups.io Notification <noreply@groups.io>
Sent: Sunday, March 6, 2022 7:23 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 
Don Weigt <dweigt47@...> updated the album Car lighting keep alive cap: Greg Harter's passenger car lighting board with added capacitor. Greg reports lighting is constant for more than five seconds after power is removed from the rails. One photo is of the car with DCC power on the rails, the other after about five seconds without power. Can you tell which is which? The lighting board is from Walthers. The wires to the capacitor can be thin, as typically used wiring decoders. lt is possible long passenger trains with multiple cars would cause a problem by briefly drawing too much current when power is applied. If that happened, one fix would be to put a ten to about twenty Ohm resistor in either capacitor lead. This would reduce "keep alive" time a bit, as well as add complexity. The total modification cost per car would still be under half a dollar if the parts were bought from most online sources.



Pete
 

George,
Looks like you have a = sign in the email address instead of an @ sign..
Kayakerpc@... 
Thanks,
Pete


On Thu, Mar 10, 2022 at 9:04 AM, george hohon3
<Hohon3@...> wrote:
Pete, I tried the email address from your post and it failed to go through.  Do you have another one?

From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Pete via groups.io <Kayakerpc@...>
Sent: Thursday, March 10, 2022 7:02 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 
George,
I would like to have the schematic too.
Thanks,
Pete


On Thu, Mar 10, 2022 at 4:42 AM, Robert Heroux
<rheroux@...> wrote:
George -

I would be interested in the details etc.

Thanks

Bob







On Mar 9, 2022, at 20:58, george hohon3 <Hohon3@...> wrote:

Here's my solution for passenger car and caboose lighting on an HO scale DCC layout:
  • 1A 50V Bridge Rectifier
  • 270 Ohm 1/2 watt Resistor (for in-rush current protection)
  • 470 /35 W Capacitor  (just a bit larger than track power)
  • 4.7K Ohm 1/2 watt Resistor  (brightness control for LED lights)
  • LED light strip (3 LEDs minimum)
There are no apparent "in-rush" current problems.

Brightness might be too bright, requiring a higher rated resistor (dependent on strip LED).

Flicker free operation is perfect, as in, there is no flicker!

If you're interested in the details, photos and the wiring schematic, let me know.

George 



From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of w4dccqa@groups.io Notification <noreply@groups.io>
Sent: Sunday, March 6, 2022 7:23 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: [w4dccqa] Updated album Car lighting keep alive cap #photo-notice
 
Don Weigt <dweigt47@...> updated the album Car lighting keep alive cap: Greg Harter's passenger car lighting board with added capacitor. Greg reports lighting is constant for more than five seconds after power is removed from the rails. One photo is of the car with DCC power on the rails, the other after about five seconds without power. Can you tell which is which? The lighting board is from Walthers. The wires to the capacitor can be thin, as typically used wiring decoders. lt is possible long passenger trains with multiple cars would cause a problem by briefly drawing too much current when power is applied. If that happened, one fix would be to put a ten to about twenty Ohm resistor in either capacitor lead. This would reduce "keep alive" time a bit, as well as add complexity. The total modification cost per car would still be under half a dollar if the parts were bought from most online sources.



 

Thanks George,
Can I get a copy of the details.
- Michael Boyle
boyle10017@...


Don Weigt
 

The values George gave will work fine.
The bridge rectifier is about as low a rating as you can get, so it will be small and inexpensive.
The 270 Ohm resistor will limit the inrush current to about 0.06 Amperes, so many lighted cars in a train will work without overloading most boosters. The peak inrush current and voltage across the 270 Ohm resistor momentarily creates a 1 Watt power level, but it will drop off quickly to about 1/100th Watt, so a 1/4 Watt resistor, which is much smaller, can be used in place of the 1/2W.
Same for the 4.7k Ohm resistor. If the cap reaches 16 V DC, which is highly unlikely, the current will still be less than 4 milliAmps (0.004 Amperes) That gives a steady state power level less than 0.064 Watts. A quarter Watt resistor would be fine here, too.

The 470 uF capacitor will indeed keep the lights on for a long time used with that 4.7k resistor. The time constant (time to drop to 37% of the initial voltage)  of the resistor and capacitor is about 2.2 seconds, and many of these capacitors have a higher capacitance than their nominal value, tolerances being something like +50% or +100% and -20%. Given the working voltage for HO and smaller gauges should be less than 16V, a 25V capacitor of about half the size could be used in place of the 35V one. The 35V part will have a longer life, all else being equal, but both will probably last for the lifetime of the cars.



--
Don Weigt
Connecticut


Paul R Greenwald
 

George -

How about a putting schematic in photos or files?