Replacement RCX adapter

[Duq]

I have a v1.0 RCX and I'm looking for a replacement adapter. So this needs to be:

Input 220-240 AC, UK or European plug.

Output 9-12V AC, 7VA, 5.5x2.1mm plug.

I would have thought this would be easy to find but I'm having a hard time with Amazon and eBay. AC to AC adapters turn out to be rare.

Does anyone have suggestions for where to get an adapter? Would it be worth getting a 9V DC and taking out the rectifier? Has anyone done that and are there models that are easy targets for that operation?

 

[Toastie]

40 minutes ago, Duq said:

Does anyone have suggestions for where to get an adapter? Would it be worth getting a 9V DC and taking out the rectifier? Has anyone done that and are there models that are easy targets for that operation?

Hi Duq,

this is absolutely not necessary. You can use >any< 9 … 18 V >DC< wall wart as well. The bridge rectifier inside the RCX is very happy with both, AC and DC supply. I recommend a reasonable 12 DC power supply. My RCX' run happily on 15 V DC für years now. Center is "+", shield is "-".

Best,
Thorsten

 

 

 

 

 

 

[Duq]

Thanks Thorsten. My worry is the stories about damaging the rectifier if you use a DC adapter: 

https://pbrick.info/2013/10/using-an-adapter-to-power-the-rcx-1-0/

What do you power with your RCX? I'm planning on using it to run trains.

[Toastie]

You are very welcome!

OK, I checked that reference, but it does not make any sense. Really.

I am powering switch drives with DC powered RCX, bridges and lights, as well as trains, see examples below.

In any case, all RCX are powered off from the track or DC wall warts. The track is permanently powered using an old 15V/8A laptop power supply.

It gets even better: When you run a train with an RCX and you have some track power pickup means, any polarity change will never hurt the RCX (e.g. when traversing (electrically isolated) reversing loops etc.). The built in bridge rectifier always takes care of that. Don't even worry when your DC supply has "+" polarity on the shield an "-" on the center: It works. 

You can also see that the first thread is 9 years old. These trains still happily run around - with "frequently" changed (every year or so) backup batteries, to keep the programmed RCX bricks intact when track maintenance is scheduled. And that change is >only< a safety measure - I don't want any batteries leaking and corroding the contacts within the battery housing. Basically the batteries are never doing anything. They just serve als UPS systems.

Best
Thorsten

[JopieK]

@Duq: A rectifier is just a couple of diodes. You will only damage them if you give them too much power or draw too much current. Batteries are also directed current you know.

[Tcm0]

I think that one might have to check the type of the diodes to be completely sure. They might not be made for constant 9V.

[Toastie]

OK, I can only repeat:

My RCX's are from 1998, 2001, and some are from 2005. I have total of 10 (the V1.0 type). 4 of them run on 15 V DC power since more than 8 years, see above. What else should we check to be completely sure?

To be honest, I believe they will give up because they are that old, but not because of the DC supply. Even sometimes washing machines need to be replaced after one or two decades ...

Best,
Thorsten

 

[Duq]

Thanks for the tips Toastie, I've ordered this:

https://www.amazon.co.uk/gp/product/B00CXYNV48/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

[Toastie]

You are very welcome.

Looking good - just make sure, the thing does not deliver >15 V DC (without load) - but I don't think so.

Best
Thorsten