I'm too lazy to build a circuit, I just use the old fashioned Marx method of activating crossing lights .
Well, here is the final board. It works!
I need to shrink this down. I have another circuit design in the works to fit under the crossings themselves.
Anyone interested? I have 5 of these 😃
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I shrunk the board down and got rid of the giant cap.
Once the boards come in I will test and then start to put them on sale.
I was thinking $15 for a board. What does everyone think of the price?
I would like to try a couple. There is no email address in your profile. How does one contact you?
My email address is in my profile.
Integrated fuse traces?!!! Sorry, I'm not trying to rip into you, but come on, please say you revised that board before you go selling them.
Until you show the actual new board design, I would pass.
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Again, sorry for the blasting tone. I said what I said because of this: "I shrunk the board down and got rid of the giant cap" doesn't address other major shortcomings from a design perspective.
Again, sorry, we all start somewhere, mistakes are made. Easy enough letting a board patterning software make decisions for you. That said, between just ridiculously over sized components (TO-3P, massive 5.08mm screw terminals, massive SMD resistors) and then the smallest possible traces connecting them, this is near textbook how not to make a PCB and definitely not one to sell.
By all means post a preview of your new design that is smaller, but what I trying to advise you of is this board- to anyone who knows anything about electronics casts doubts on your skills for designing a product worth selling. Understanding component design, sizing, thermal calculations are all part of designing a proper board. Understanding thermal stress just from soldering, good through hole pad guidelines, trace width and size, these are required to making something that can stand up in the field.
Again, I'm sorry, I know you mean well and it's fun to make something and when it works you are very happy. There is plenty of room in this hobby for folks to create electronic boards that perform model railroading functions. I wish you best of luck and again, suggest you post some layout designs of your new board so others can help guide you on a much more robust PCB design that is much more viable for a product.
@Vernon Barry posted:Again, sorry, we all start somewhere, mistakes are made. Easy enough letting a board patterning software make decisions for you. That said, between just ridiculously over sized components (TO-3P, massive 5.08mm screw terminals, massive SMD resistors) and then the smallest possible traces connecting them, this is near textbook how not to make a PCB and definitely not one to sell.
By all means post a preview of your new design that is smaller, but what I trying to advise you of is this board- to anyone who knows anything about electronics casts doubts on your skills for designing a product worth selling. Understanding component design, sizing, thermal calculations are all part of designing a proper board. Understanding thermal stress just from soldering, good through hole pad guidelines, trace width and size, these are required to making something that can stand up in the field.
Again, I'm sorry, I know you mean well and it's fun to make something and when it works you are very happy. There is plenty of room in this hobby for folks to create electronic boards that perform model railroading functions. I wish you best of luck and again, suggest you post some layout designs of your new board so others can help guide you on a much more robust PCB design that is much more viable for a product.
With all due respect, thank you for raining on his parade. While I agree wholeheartedly with your technical analysis, and thank you for it, your comments are near textbook on how to discourage people not to pursue their dreams.
This forum is not generally about critiquing electronic designs, although we do it from time to time. It's about coaching and encouraging success within our core hobby, which is fortunately not electronics.
Mike
@Vernon Barry posted:Again, sorry for the blasting tone. I said what I said because of this: "I shrunk the board down and got rid of the giant cap" doesn't address other major shortcomings from a design perspective.
Again, sorry, we all start somewhere, mistakes are made. Easy enough letting a board patterning software make decisions for you. That said, between just ridiculously over sized components (TO-3P, massive 5.08mm screw terminals, massive SMD resistors) and then the smallest possible traces connecting them, this is near textbook how not to make a PCB and definitely not one to sell.
By all means post a preview of your new design that is smaller, but what I trying to advise you of is this board- to anyone who knows anything about electronics casts doubts on your skills for designing a product worth selling. Understanding component design, sizing, thermal calculations are all part of designing a proper board. Understanding thermal stress just from soldering, good through hole pad guidelines, trace width and size, these are required to making something that can stand up in the field.
Again, I'm sorry, I know you mean well and it's fun to make something and when it works you are very happy. There is plenty of room in this hobby for folks to create electronic boards that perform model railroading functions. I wish you best of luck and again, suggest you post some layout designs of your new board so others can help guide you on a much more robust PCB design that is much more viable for a product.
Hi Vernon,
First off I want to say: I am not planning on selling these whatsoever. As you pointed out about some aspects about the board layout: this board simply put, is a far way from sale material. I have just been using them for my personal train layout for the past year or so and it seems like that is where they will live! Never say never, but I doubt I will ever be selling any boards. There's a number of reasons for this, I think the biggest is that I am not too happy with the trade-offs of this circuit design in general, even before getting down to the board level. I have been re-thinking ways to produce the waveforms necessary for this with the correct input requirements and I have a few new circuits that can do it. Also, I won't have the bandwidth to do much customer service which I believe is necessary to sell a product like this. No need to be sorry either, in fact I did say "judge away" when it came to this design, because it was my first time ever laying out a board like this.
I have no issues with your response at all! It's passion. I appreciate the constructive criticism and I would really appreciate some help and guidance if you would be willing to provide some more detailed advice! I can provide all the design files you need. I do have some more detailed and direct questions about some of the things you mentioned. Based on your response, it sounds like you have professional electrical engineering experience with products shipped under your belt, so it will be nice to talk some shop 
I think it may be best to take it to another venue though, as Mike mentioned this isn't the typical spot for this type of thing. Let me know if this is something you are interested in. I would appreciate the guidance.
I had not seen this thread before, but @gunrunnerjohn's transistor circuit, evoked vivid nostalgic memories for me. It's called an astable multivibrator and was one of the first transistor projects I built in the late 1950's. (I may have also given away @gunrunnerjohn's age 
) I may have seen the design in a Popular Electronics back then.
The astable multivibrator was first invented during WW1 by two French professors Henri Abraham and Eugene Bloch using the just-invented triode vacuum tube. Its application was to help precisely measure radio frequencies and used by the French, English and U.S. military. They both continued to make other advancements radio wave engineering in later years.
The Gestapo arrested Abraham in 1943 and Bloch in 1944. Both were murdered in the Auschwitz Concentration Camp.
@Bruce Brown posted:I had not seen this thread before, but @gunrunnerjohn's transistor circuit, evoked vivid nostalgic memories for me. It's called an astable multivibrator and was one of the first transistor projects I built in the late 1950's. (I may have also given away @gunrunnerjohn's age
The astable multivibrator was first invented during WW1 by two French professors Henri Abraham and Eugene Bloch using the just-invented triode vacuum tube. Its application was to help precisely measure radio frequencies and used by the French, English and U.S. military. They both continued to make other advancements radio wave engineering in later years.
The Gestapo arrested Abraham in 1943 and Bloch in 1944. Both were murdered in the Auschwitz Concentration Camp.
Bruce,
Thanks for the History lesson! Very fascinating. Sad ending, unfortunately.
As for the theory, I took an IC design class in college and I remember learning about this! That's where I pulled this from when I came up with the design. This theory is very elegant. Abraham and Bloch did tremendous work. I have an electronics textbook that outlined this and it made the most sense. There's also the mono-stable (one stable state) and bi-stable (two stable states) multivibrators. They are used all over today. The astable multivibrator means there is no stable state, so it oscillates. I remember learning how to design clock generators and oscillators with this theory in mind.
The simplicity of this design is its greatest asset
Thanks for the trip down memory lane back to EE school!
