LM testing board

[G8B4Life]

I've been umming and ahhing for some time on posting this contraption (and too lazy to take the photo), but this recent thread has prompted me to do so.

As some would realise by now I do a bit of testing. Not wanting to have to put an LM into a model to do the majority of the testing and not wanting to have an actual model on the desk beside me I built this; a done on the cheap LM testing board.



While it's not as nice and complete as commercial boards the price was correct, the whole contraption cost only a few dollars. The stripboard I already had from years ago and the LED's and screw terminals from previous eBay purchases (which were cheap). The harnesses are DigiTrax and Ring Engineering, probably the most expensive items on the whole board (not including motor).

The yellow wires go to the PWR-56. I use the PWR-56 for convenience for turning the power off to the board just by using HC Simulator.

The harness wires are simply wired to each strip on the stripboard, so the LED's are not in numerical order but harness order, vis 3,1,2,4.

The motor is from a model that is in pieces at the moment and will be replaced by a cheap motor. That's why it's not secured to the board.

The brown wires in the bottom are the speaker outputs. Right now I've got those brown wires in and they go to a set of headphones (now that makes RP loud! but I may add a headphone jack as well so I've got listening options; headphones or wire a test speaker in.

Above the speaker wires is the 2 inputs (LM-2) or the Input and Negative (LM-3).

Everything has screw terminals for easy replacement of wiring if it should break.

The testing board has been a boon to me, I just sit here at my computer and program and test LM's using HC Sim with the testing board sitting right on the desk with the CI-1 just a few inches away. Once the major work is done I can then pop the LM into the loco and do fine tuning on track with the HC-x.

- Tim

[Alan]

What sort of testing do you do?

[G8B4Life]

Bug hunting and testing mostly (yet I am not a beta tester!). I do this as I discovered that things apparently weren't being tested by the beta testers because their models don't use some features. The board allows me to test all the outputs and effects etc without the hassle of installing a module into a loco that can use all the features.

I also used the board when writing the user guides; the loco in the screen captures in the guides doesn't actually have a LM in it.

The board also makes a great platform to firstly test a new out-of-the-packet LM and then install and configure the major items before putting it into a locomotive. This was actually the primary reason for making it.

- Tim

[Alan]

That makes sense. Not being a sound user there is virtually nothing to setup when I do an install other than the adjustments best made on the layout - acell, decel, mom, etc. 

[nodcc4me]

That's a nifty gadget Tim.

Alan, as technically inclined as you are, it's hard to believe you run your trains without sound. 

[Alan]

That's a nifty gadget Tim.

Alan, as technically inclined as you are, it's hard to believe you run your trains without sound. 

Two reasons really. The majority of my roster is Fairbanks Morse 1,500 and 1,600 HP. No files available nor is there likely to ever be. An opposed piston motor sounds like no other. I grew up listening to it. That makes prime mover sound substitution out of the question for me. Even if files were available I find the tonal qualities of on-board sound totally inadequate and toy like. To my ears it misses the mark by so much I would rather do without and let my imagination fill in the silence. No disrespect meant to sound users. It's a personal thing.

OP FMs are still in service in stationary applications. I have entertained thoughts of recording one and then MUing modules together, one in the loco and the other on a pair of headphones. Solves the tonal quality problem but is not without its own challenges.