Simple shuttle for DC operation

[dutchelm]

If you are using this circuit I would suggest you reverse the relay connections, ie swap the input & output. Wired like it is if one contact is slower than the other you put a short on the power supply.

 

[Neil Robinson]

Could R2 and C1 be replaced by pots to give controllable variable time delay?

Yes, the arrow through the resistor symbols mean that they are variable resistors with a maximum resistance of their stated value.

 

[Greg Elmassian]

From looking at the schematic, all this does is reverse the polarity every so often... My understanding of a shuttle, is something that goes to one end, stops for a bit, then reverses and goes to the other end.

You need at least diodes in the rails to break power in the "wrong direction", so at the least that is missing from the description, even though this may be obvious to some...

In this case, the diode-isolated section should be long enough that the train will coast to a stop while still on the rails and not running into anything.

I actually prefer ones with a trigger, and the "diode logic" as a backup.

 

[Gavin Sowry]

From looking at the schematic, all this does is reverse the polarity every so often...

Which is all I want to do, in this instance.

 

[Greg Elmassian]

good for you, was wondering about the OP.... I think he wants to buy not build.

 

[trammayo]

Heathcote Electronic Home page

www.heathcote-electronics.co.uk

They have a simple shuttle unit.

 

[playmofire]

Heathcote Electronic Home page

www.heathcote-electronics.co.uk

They have a simple shuttle unit.

I've used one of his shuttles and they work well.