Transistor to throw a CDU
Posted
#230238
(In Topic #12595)
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I am still at the planning stage and am going to be using a cdu to throw the points.
However, as this will need to be a modular board that can be taken apart, the connectors to join the boards to the control board won't cope with the current with one cdu in the control board.
so my thinking was to use a CDU on each board (so 3) then a transistor at the points to act as a switch.
The control board would only then need to run low amp current to the transistor to throw the points. So two transistors per point.
Has anyone tried this? and would it work?there is the discussion of the planned layout here
Many thanks
Last edit: by Jon Miles
Posted
Site staff
http://brian-lambert.co.uk/Electrical.html#One
basically a CDU per solenoid.
In the book Model Railroad Electronics by Peter J Thorne,he describes a circuit that uses SCR's per solenoid
Amazon.com
Ron
NCE DCC ; 00 scale UK outline.
NCE DCC ; 00 scale UK outline.
Posted
Inactive Member
Using a transistor to switch a CDU would probably fry most Transistors, so using either a relay or SCR would be the way to go.
Now I've finally started a model railway…I've inherited another…
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Seems complicated. The intermodule connectors I use handle 30 amps. That said, I think I'd go with Ron's suggestion and use one cdu per module where there are turnouts. Keeps the wiring simpler.
Nigel
©Nigel C. Phillips
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In no particular order
I was considering a 20amp transistor to avoid cooking it, but am in the theoretical realms here as I am still learning!
Relays I did look at but they seem overly pricey. As did a CDU on each point, although the diagram of a simplified system from Brian Lambert did seem a possibility.
I was wondering Nigel, what type of connector do you use?
And sorry, what is an SCR?
Many thanks and sorry for all the questions.
Posted
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Anderson Powerpoles. There are other compatible ones. Now the de facto standard for module clubs here.
Nigel
©Nigel C. Phillips
Posted
Inactive Member
I'm still learning after all these years.
Why not just a SPDT switch with a capacitor and a common return?
Like the one in Sol's link. I've made one as a demo and it worked a treat.
What am I missing?
Max
Port Elderley
Port Elderley
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I was trying to reduce the current through the connector MaxSouthOz, so I thought using a transistor as a relay.
Posted
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I've graduated from solenoids and stall motors to servos, so my recollections may be flawed. :roll:
Max
Port Elderley
Port Elderley
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Mike
Pig Hill Yard - a small Inglenook shunting layout for my boys, in 00.
Pig Hill Yard - a small Inglenook shunting layout for my boys, in 00.
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Site staff
My friend has had a PCB made for the one capacitor version and this is the layout and wiring needed
the PCB is about 25 x 55mm
Ron
NCE DCC ; 00 scale UK outline.
NCE DCC ; 00 scale UK outline.
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Last edit: by Roy Low
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In the end i went with an arduino to control the points and mimic panell with relays for the points and isolations or sections of track
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