Wiring a siding - peco bullhead and DCC

[rob D2]

Hi folks,

Im just building another plank using my preferred code 75 bullhead with prodigy DCC ( although that’s probably not relevant ).

I seem to be having a brain f*rt about wiring the sidings  - I’ve always put two isolating rail joiners after points and fed each siding separately . I’d like to do that again , but I’d rather not use isolating railjoiners as they look a bit rubbish with the bullhead .

So if I use the metal fishplates and put a feed in to the siding , will the siding be fed twice by the power feed at the toe of the points and its own one ? Is this an issue electrically ?

 

Im not using powered frogs initially ( unifrog ) as the baseboard I’m precludes point motors so the points will be manually indexed or push rods.

 

Any thoughts appreciated ?

[5BarVT]

Here’s a link to wiring of unifrog points

 

https://dccwiki.com/PECO_Unifrog

 

The frog isolation is done within the point so the V rails are already connected to the stock rails.  So running on without insulation will make no difference as both sets of rails are already connected.

 

Thanks for the prod to go and see exactly how unifrog are wired.

 

Paul.

[rob D2]

50 minutes ago, 5BarVT said:

Here’s a link to wiring of unifrog points

 

https://dccwiki.com/PECO_Unifrog

 

The frog isolation is done within the point so the V rails are already connected to the stock rails.  So running on without insulation will make no difference as both sets of rails are already connected.

 

Thanks for the prod to go and see exactly how unifrog are wired.

 

Paul.

That’s interesting Paul,

I think my question is more generic GCSE electrics…..in so much as am I doubling the track voltage by having two feeds ? 

[RFS]

36 minutes ago, rob D2 said:

I think my question is more generic GCSE electrics…..in so much as am I doubling the track voltage by having two feeds ? 

 

It's advisable with DCC to have multiple feed wires and not rely on rail joiners alone. I have a track feed on every piece of rail. You're not doubling the voltage in this way - but you could be reducing the voltage if you don't have enough feeds. 

[Dungrange]

1 hour ago, rob D2 said:

I think my question is more generic GCSE electrics…..in so much as am I doubling the track voltage by having two feeds ? 

 

No you are not doubling the voltage.  All you would be doing is providing multiple paths along which the electricity can flow (ie via the rails and rail joiners or via whatever wiring you add under the baseboard).  The impact of having multiple feeds is to reduce the resistance and therefore reduce any voltage drop that would occur as a result of resistance in the circuit.

[rob D2]

Thanks guys,

I was trying to do V=IR squared or summat and getting nowhere !

[Pete the Elaner]

Think of each wire as a resistor (which is exactly what they are: resistors which are so low, we usually ignore them).

By providing 2 feeds, you are effectively placing the 2 resistors in parallel.

There is only 1 voltage source, so you cannot add to it with a simple circuit.

[Michael Hodgson]

1 hour ago, rob D2 said:

 

I was trying to do V=IR squared or summat and getting nowhere !

 

Not squared - it's simply Volts = Amps times Ohms. 

 

So assuming you are using suitable connecting wire duplicating (or better, adding several more) feeds doesn't change the voltage directly - it reduces (extremely slightly) the resistance in the feed wires between the controller and the track, so the voltage wasted as resistance in the feeds is also reduced meaning more of the supply voltage reaches the track,  but only by a negligible amount.

[rob D2]

Thanks guys, I cannot remember much about electrics

[DCB]

Ah DCC. I see..  Its a Non DCC Topic.

Edited March 29, 2023 by DCB

[ejstubbs]

3 hours ago, DCB said:

You need an isolating rail break and on off switch if you want to park a loco in the siding and run trains on the main line over the point. 

 

Er, the OP's layout will be DCC...