Cheap accessory decoder or DCC controlled relay

[WIMorrison]

I want to switch a couple of relays using an accessory address, but I can't find anything under around £30 for 2 addresses, which seems expensive to me. I could use a DR4018 which would switch 16 relays working out at £2.25 per relay, however I don't (currently have a need to switch that many). The relays cost a couple of quid each.

 

Does anyone know of a cheap accessory decoder, or a DCC controlled relay that would fit the bill - specifically cheap

[trevora]

could you use this

https://forum.mrhmag.com/post/sma20-low-cost-17-channel-dcc-decoders-ver-6-01-with-soundtriggered-soundstepperdual-motorled-and-12201920

arduino plus relay after the dcc interface £5.00 worth of bits

[BoD]

I may be way off the mark here as I don’t know the voltages or current involved but could you use the auxiliary outputs from a cheap loco decoder.? Yes, the two relays would use the same address but switched by different functions of that address.

[BroadLeaves]

How about a Digitrax TR4, at £17.20 from https://www.digitrains.co.uk/tf4.html 

That has four outputs rated at 125mA continuous as per https://www.digitrax.com/media/apps/products/function-decoders/tf4/documents/TF4.pdf , which should be enough to drive a small relay.

[WIMorrison]

I did think about function only decoders, however that means I need to control them as a loco and select the function I want and operate it, which isn't as easy to control as a DCC Accessory - but it does have its attractions

 

LAIS sell a 4 function decoder (860011) which is around £10 with 100mA per function which might prove useful.

[RFS]

What about the NCE Switch-IT? It's designed for two Tortoise motors but I would have thought a couple of non-latching relays would work just as well. There's a couple of new ones on Ebay at the moment for £15.

[NFWEM57]

On 14/02/2022 at 19:57, WIMorrison said:

I did think about function only decoders, however that means I need to control them as a loco and select the function I want and operate it, which isn't as easy to control as a DCC Accessory - but it does have its attractions

 

LAIS sell a 4 function decoder (860011) which is around £10 with 100mA per function which might prove useful.

What are you trying to control? A fixed item or something in rolling stock?

[WIMorrison]

2 minutes ago, NFWEM57 said:

What are you trying to control? A fixed item or something in rolling stock?

As I said in the original post, it is for the control of relays.

[melmerby]

Hi Iain

This topic seems to have died!

 

Are you still after a DCC accessory decoder operating relays?

How about using an Arduino?

You can get relays suitable for using with an Arduino and you can configure the Arduino as a DCC accessory decoder

 

Buy an Arduino Nano clone, some stripboard and the opto coupled relays and away you go.

You'll need some way of providing the Arduino with 5v or so.

[RAF96]

Any solenoid suitable acc decoder will work as all you do it fire the pulse < > into the coil of a latching relay pair. I have used the method for firing the output of a CDU thru’ the relay main contacts as a method of having DCC control and parallel manual switching of solenoids. In my case the relays are non latching as the pulse pulls the relay in long enough to discharge the CDU.

Several folk market single motor control acc decoders , e.g. Train-Tech. Or you could use as suggested a loco or function only decoder, in which case the directional lighting output would drive either way according to loco direction.

[melmerby]

2 hours ago, RAF96 said:

Any solenoid suitable acc decoder will work as all you do it fire the pulse < > into the coil of a latching relay pair. I have used the method for firing the output of a CDU thru’ the relay main contacts as a method of having DCC control and parallel manual switching of solenoids. In my case the relays are non latching as the pulse pulls the relay in long enough to discharge the CDU.

Several folk market single motor control acc decoders , e.g. Train-Tech. Or you could use as suggested a loco or function only decoder, in which case the directional lighting output would drive either way according to loco direction.

IMHO Terribly old fashioned

Many years ago I was using Thyristors (using DC & CDU) or triacs (using AC) to operate solenoid motors, much more elegant than relays.🙂 (I was using chunky Hammant & Morgan point motors)

 

Again you could use an Arduino as an accessory decoder to operate the CDU system.