Comments on: Block Wiring and Stopping LED’s from Burning Out https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html?utm_source=rss&utm_medium=rss&utm_campaign=block-wiring-and-stopping-leds-from-burning-out Model railroads and model trains Fri, 27 Feb 2015 01:08:37 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: Shaun https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8659 Fri, 27 Feb 2015 01:08:37 +0000 http://blog.model-train-help.com/?p=3460#comment-8659 Thanks Frank – I found a wiring system that will do my cab indications – but I was also trying to work out a switch indication system. The one big problem was how to show switch position independent of block cab indication.
My switches are wired with jumpers across the diverging tracks beyond the frog – so will always indicate the same regardless of direction – could this be “fixed” with leds?

]]> By: Frank Bushnell https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8603 Wed, 18 Feb 2015 21:55:25 +0000 http://blog.model-train-help.com/?p=3460#comment-8603 Because of track polarity reversal on a DC layout, put two LEDs in inverse parallel (opposite ways round) with one resistor (1kOhm) in series with the pair. If the LEDs are different colours, they will also form a voltage polarity indicator.

Alternatively, a diode bridge can be used to supply the single LED & resistor. (Nice tiny IC bridge chips are cheaply available.)

If your purpose is to show which way the switch is set (regardless of track polarity), grain-of-wheat (or grain-of-rice) bulbs across the rails will also do the job.

There are also accessory (electrical) switches that fit under the (track) switch to indicate the direction it is set.

]]> By: shaun https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8549 Fri, 13 Feb 2015 00:08:50 +0000 http://blog.model-train-help.com/?p=3460#comment-8549 Thanks people for your ideas.
My leds have come from scrap electronics – so at the right price.
I’ll be using miniature on/off/on switches with a led wired across the output terminals, with the cabs wired in opposite polarity.
Will try a 1k resistor and see what happens.

]]> By: curtis https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8542 Thu, 12 Feb 2015 09:05:15 +0000 http://blog.model-train-help.com/?p=3460#comment-8542 if you got access to a junk yard or some late model junkers the dash assys have small resisters for each dash light because the 12 volt leds cant take the alt surges volts. i have a truck dash that gave me 12 tiny led lights that plugin and the 12 resistors that go with them.i use these and have had no problems on board or in any home made signals.

]]> By: shaun https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8540 Thu, 12 Feb 2015 01:01:08 +0000 http://blog.model-train-help.com/?p=3460#comment-8540 Thanks for your replies, diodes will receive full track voltage with one leg tied and resistored, so they won’t carry track current.
I also have thousands of infared diodes ( sender and receiver in a little combined head ) if anyone has a use for them.

]]> By: gio https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8537 Wed, 11 Feb 2015 20:08:42 +0000 http://blog.model-train-help.com/?p=3460#comment-8537 evans desings leds come ready to go in many sizes y may power w track power 9volt or 3 volt batterywatch type ,aa ,or aaa they come in a variety of colors ,including flashing leds as well it has endless posibilities with out the hassle of soldering &calculating resistors

]]> By: Geoffrey Logan https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8527 Tue, 10 Feb 2015 17:20:04 +0000 http://blog.model-train-help.com/?p=3460#comment-8527 If you are using a 12volts DC supply then most common LEDs that operate on 1.3 volts need a1000ohm resistor

]]> By: Newman Atkinson https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8525 Tue, 10 Feb 2015 16:47:29 +0000 http://blog.model-train-help.com/?p=3460#comment-8525 In reply to Kevin.

Yep Kevin is absolutely right, Don’t forget the resisters. Your lights will last a very long time.Newman

]]> By: Kevin https://blog.model-train-help.com/2015/02/block-wiring-and-stopping-leds-from-burning-out.html#comment-8507 Tue, 10 Feb 2015 07:27:41 +0000 http://blog.model-train-help.com/?p=3460#comment-8507 Hi Shaun you will need to add a current limiting resister to the anode lead of the L E D this will need to be calculated to the voltage that you will be having on the switch.

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