Radio Control with DC Track Power

[wasdavetheroad]

Has anyone any experience of building one of these diagrams from the Deltang site?  

I have just ordered myself an early xmas present which is an OO scale Andrew Barclay 0-4-0 saddle tank loco. Because of aging hand problems I have great difficulty with complex construction and anyway the loco has room for a decoder or Deltang Rx but fitting batteries is going to be extremely difficult.

 

The loco will run on its own section of the layout ( exchange sidings and quarry sidings) with no access allowed to the  main lines. BR locomotives will have access to the exchange sidings and will continue to run on batteries.

 

To start with I hope to have say 12V DC from a regulated power supply feeding a Deltang Rx which supplies the track and is controlled by a spare Deltang Tx I have.  The loco will retain its power collectors and requires no modification out of the box. If this works OK I will proceed to stage 2.

 

Stage 2 involves fitting the Rx to the loco with the rectification circuit etc and this should allow for more than one loco to be controlled from the Tx with the advantage of the full 12V being supplied from the rails.

 

 

[Simond]

looks perfectly sensible

 

With suitable voltage regulation, it would also work on DCC-supplied track too.

 

 

[wasdavetheroad]

Yes, according to Deltang it should work with DC, AC and DCC power.

 

It occurs to me that if you are using the Rx off layout and supplying the track via a Tx acting as a remote throttle the regulated power supply would mean no need the rectification circuitry?

 

This is the latest plan for the layout, Kato HO Unitrack, Green are the quarry lines/ Exchange sidings. Building works are almost compete so maybe track laying can start in early December. No station names yet.

 

 

[Nigelcliffe]

On 14/11/2021 at 08:22, wasdavetheroad said:

Has anyone any experience of building one of these diagrams from the Deltang site?  

I have just ordered myself an early xmas present which is an OO scale Andrew Barclay 0-4-0 saddle tank loco. Because of aging hand problems I have great difficulty with complex construction and anyway the loco has room for a decoder or Deltang Rx but fitting batteries is going to be extremely difficult.

 

 

Accepting your limitations of dexterity,  the Barclay does have a moderate amount of room inside it for those more able to attack things.  At the "decoder socket" end of things, there's quite a lot of space, and an unnecessary metal peg supporting the decoder socket.  At the smokebox end, a fair bit of the internal plastic around the smokebox can be cut away, creating more space, particularly in the high water tank versions.    Between those spaces, I found enough room for a DCC sound decoder, stay-alive module and speaker, and a small 4-pin plug/socket to split the chassis from body for maintenance.   So, there may be enough space for a small battery and the Deltang Rx unit.   

 

Using your rectifier circuit, I see no reason why you couldn't substitute a very large capacitor (even to the level of a DCC stay-alive ready-made unit, which has inrush current components for the large capacitor), and thus not suffer any pickup issues.  

 

 

-  Nigel

[wasdavetheroad]

The loco should arrive today and I will use an old gaugemaster controller to try it out on DC first. If it passes that test I will try using a Deltang Rx to power the track using a regulated power supply. The Deltang Tx control will solve the fixed position DC controller problem.

 

The IMPORTANT question, how do you prevent a short circuit on the track frying the Deltang Rx

 

edit - the loco just arrived, it is beautiful.

 

 

[Nigelcliffe]

10 hours ago, wasdavetheroad said:

The loco should arrive today and I will use an old gaugemaster controller to try it out on DC first. If it passes that test I will try using a Deltang Rx to power the track using a regulated power supply. The Deltang Tx control will solve the fixed position DC controller problem.

 

The IMPORTANT question, how do you prevent a short circuit on the track frying the Deltang Rx

 

 

 

At the minimum, one diode in one of the supply wires protects against voltage the wrong way.  Then, track voltage the wrong way and nothing flows.   

 

Wheels short-circuiting means no current goes to the Deltang, so nothing to protect over there.  

 

Alternative to the diode is a rectifier, as in an earlier posting.   But if doing that, and doing it to allow power-from-DCC, then use "fast recovery" rectifier diodes.  

 

- Nigel

Edited November 16, 2021 by Nigelcliffe

[wasdavetheroad]

I tested the loco this evening and it looks as if the best solution if possible is to fit radio control and battery power. My layout points have insulated frogs and there are stalls on the points unless moving at a fair speed, faster than I would want. I fished my converted Smokey Joe out and it cruised happily over the points at I calculate about scale 12mph. Its problem is the awful motor and stiction so the 3.7V from a single battery is marginal in starting the loco. Once started the speed can be reduced. The pleasure of no rail power. I know there is no way I can now do a RC conversion so I will have to investigate getting a commercial job. I think there is a topic here somewhere about slow running industrial locos so might try a different loco

 

Thanks everyone for the advice