I actually used Froogle to get everyting but the 1K resistors and the push button Moms. I’ll drop $20 at RS. 16 push buttons and 40 1K resistors.
Could be worse.
Could you not just wire a Red LED/resistor across the block gap to show block polarity, if the polarity was different the LED would light…
You could also wire a 2nd Green LED/resistor across the block gap but to the other rail, if that polarity was different then it would light meaning polarity on the other rail was different…
Here’s GOOD LED site
http://www.superbrightleds.com/led_info.htm
And SPACEMOUSE,
Your original idea would have worked very similar to the DPST w/N.O. pushbutton. You just approached it from a different prospective… One switch for LED the other for Turnout…
DC voltage is typically used for LEDs, but not absolutly the only way. When AC voltage is rated i.e. 17VAC the actual voltage is much more from the “Peak to Peak” on the waveform, its been awhile since school, but I think its 1.4 (?) times larger so for a little while your voltage is 23.8 volts.
http://www.ibiblio.org/obp/electricCircuits/AC/AC_12.html
scada
The problem with using an LED (or any light) across the block gap is that the voltage will vary, depending on how fast the train is going. If you size the resistor for maximum voltage, the light may not be bright enough for a slow train, and if you size the resistor for low voltage, when you crank up the throttle you may blow the LED or light.
…Bob
I should have thought about that…duh…
thanks
scada
Man, did anyone expect that what seemed like a very simple situation would have so many different ideas - all of which have their own set of pros and cons?
There’s always a millon ways to do things. The wrong ways, and MY WAY! [:D][:D]
What else do you think we engineers do, besides come up with more and more ways to accomplish exactly the same thing? [:D][:D][:D][:D]
Note the smileys…I’M JOKING, PEOPLE!
This is why the engineer in me prefers Tortoises. Easier, simpler, toggles are usually cheaper than pushbuttons, and position indication is a no-brainer.
–Randy
Randy,
Yup, I agree. But usually for me its- there’s a million right ways to do things and then there is the one wrong way, which is usually the way I do it lol.
On the other hand, Randy, I’m sure you’ve spent time working on a way to do something, do it up with a bunch of stuff and then a month later see a way to do the exact same thing with one tenth of the components, one third the cost and half the time. I know I always do!!
Constantly. That’s why I switched from my original idea of using stationary decoders to run my Tortoises to using Rob Paisley’s circuit, although I am not going to use pushbuttons. I keep thinking there MUST be a way to do it without any external circuit, but such a design continues to elude me.
Bottom line: I am going to eventually use a C/MRI system for signalling and dispatcher control. However, it MUST be possible to operate the layout WITHOUT runing the computer and/or control program. That menas, with the computer OFF, all turnouts must have local control enabled. If you look at Bruce Chubb’s examples in last year’s Signalling Made Easy series in MR, you can see it’s easy to add an option to give the C/MRI and thus the dispatcher control over ‘locking’ or ‘unlocking’ the turnout for local control. But you will also see that with the very cheap and simple connection, UNLESS the controlling software is running, locla control will be disabled.
What I’ve done is built a simple open collector inverter with a pair of resistors and a transistor, that switches the common of the pushbuttons in Rob’s circuit to ground, or open-circuits it. Thus, when power is on but the railroad computer is not running, the buttons work for local control. Power up the software, which will control the ‘local power’ line, and it can disable the locla buttons until the dispatcher makes the appropriate settings.
If anyone cares… LOL
–Randy
I agree there’s the way I do ti the first time. Then there’s the way I do it the second time. And the third. And the fourth…