Wiring practices

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ConducTTor
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Re: Wiring practices

Post by ConducTTor »

Interesting scenario. Good to keep in mind for the future. Thanks for the heads up!
:wave:

Tom Dempsey
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Re: Wiring practices

Post by Tom Dempsey »

That makes no sense to me electrically, are you sure that you are not getting an interference issue. The currents are so small that if you run the wires next to each other, signals can get cancelled out. Try twisting the wires or better yet putting about an inch or so between them in the runs.

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harmi
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Re: Wiring practices

Post by harmi »

All inputs should be pulled-up to +5V through relatively large resistors (compared to mentioned 330ohms) and sufficiently small against impedance of inputs (MOhm), so e.g. 10k-33k. This will reduce sensitivity of inputs. And if not, add capacitor 100nF between input pin and ground. Although I think that debounce function was supposed to be implemented in processor programm (e.g. LOW or HIGH level lasts at least for 250milliseconds to be taken into account).
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Surovi
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Re: Wiring practices

Post by Surovi »

Does it reflect on the thickness of the wire?
Is 1.5 mm2 (cca AWG 15) sufficient for 3.5 m (approx. 11ft) of the bus?
Is the AWG 22 or AWG 23 sufficient for 25 cm (approx. 10 ") feeders (10 ft distant)?
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Surovi
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Re: Wiring practices

Post by Surovi »

Thanks :thumbup:
So, 1,5 mm2 (15 AWG) is good for a 3.5 m (11 ft) bus, and AWG 22 or AWG 23 is good for a rail feeders in TT scale?

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Richard-B
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Re: Wiring practices

Post by Richard-B »

Surovi wrote: So, 1,5 mm2 (15 AWG) is good for a 3.5 m (11 ft) bus, and AWG 22 or AWG 23 is good for a rail feeders in TT scale?
For the transverse (.e.g lengthwise on the layout) buss feeders, 14AWG (Note: only sold in even sizes...) is commonly used, both in DC and DCC wiring schemes.

For the 'drops' - track feeders from rail to the buss, I use 20AWG 'bell wire'... which is commonly sold as a red + white slightly twisted pair for wiring entry doorbells in houses. I'm not saying 22AWG would not work... but I -KNOW- the 20 does!

One reason this combination is so popular, is the availability of a correct 'suitcase' connector... the red 3M Scotchlok Electrical IDC 905. This taps 22-18AWG drops from an 18-14AWG buss run.
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Tom Dempsey
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Re: Wiring practices

Post by Tom Dempsey »

Not a big fan of suitcase connectors long term. They tend to create failures down the road, usually at the most inopportune moments. I do like the bell wire approach though.

Surovi
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Re: Wiring practices

Post by Surovi »

Thanks both!
:thumbup:

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Richard-B
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Re: Wiring practices

Post by Richard-B »

Tom Dempsey wrote:Not a big fan of suitcase connectors long term. They tend to create failures down the road
I would NEVER use the suitcase connector on anything that was going to flex...
Since they bite into the wires to form the junction... bending could create a point of failure.
That said... these are intended for automotive applications... so some vibration is fair game.

Also... I never remove the connector from the 14AWG if I rewire something... I just cut the tap wire flush and leave the connector where it is. Trying to pry the suitcase from the 14AWG could cause more problems than it is worth.
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Somewhere between San Francisco and Budapest...

Surovi
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Re: Wiring practices

Post by Surovi »

:thumbup:

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