DCC Install F9

[Joe Satnik]

A few ways to prevent test jig LED burnout:

1.) Use your Ohm meter to measure the resistance of your test jig (power disconnected, without LED).   

Figure out which direction to turn your pot to get higher resistance.

Mark the test jig/pot with an arrow indicating the direction to turn the pot (to reset to a "higher Ohms" or "dimmer" starting position)

before connecting the LED. 

2.) Make a "breadboard" test jig using resistors of various values in descending order.  Label each touch point with its resistance value. 

Touch the LED to the highest value resistor first, then work your way down. 

Hope this helps. 

Sincerely,

Joe Satnik

[jbrock27]

Hey Joe, do you ever check to see if there are personal messages sent to you?

-jb

[richg]

A few ways to prevent test jig LED burnout:

1.) Use your Ohm meter to measure the resistance of your test jig (power disconnected, without LED).   

Figure out which direction to turn your pot to get higher resistance.

Mark the test jig/pot with an arrow indicating the direction to turn the pot (to reset to a "higher Ohms" or "dimmer" starting position)

before connecting the LED. 

2.) Make a "breadboard" test jig using resistors of various values in descending order.  Label each touch point with its resistance value. 

Touch the LED to the highest value resistor first, then work your way down. 

Hope this helps. 

Sincerely,

Joe Satnik

All very good details. Store the above message.

I use the below meters for this type of test.

http://www.trainelectronics.com/Meter_HF/index.htm

For general model railroading

http://www.trainelectronics.com/Meter_Workshop/index.htm

Again, if you insist on working at what is called the component level, get the meters and suggested components by Joe.
Harbor Freight also sells a nifty set of double clip leads to help you in different test.

Rich

[richg]

I will add, you cannot use an ohm meter to measure LED resistance.

Rich