Smart Hub 2 DC plug

[JB2016]

I just posted a reply which apparently breaches this Forum's conditions as I included links to e-commerce sites. I am advised that the links have been deleted by a moderator. Anyway, these links were for suppliers in the USA and I think it's unlikely they would dispatch in small quantities to the UK.

[jodyble]

Oh no! Damn, I didnt get chance to read them. Maybe the moderator would more helpfully tell me what DC input size they have in their Smart Hub 2 so I can get it to work with a UPS rather than delete potentially helpful links that might solve this problem.  Thanks very much anyway. I don't know why they have to make it of a size that actually fits nothing at all rather than a standard plug size. Very frustrating and totally unnecessary. 

[JB2016]

Measured with calipers for OD and used the shank of a 3.0mm drill to test the ID. Of course, BT will sell you a one-hour UPS for the Smart Hub 2 which no doubt has the correct connector, but that solution costs over £80. If you search the Web for the Philmore 206 you should find the sites that I posted earlier.

EDITED:  ID amended to correct size of 3.0mm

[JB2016]

Apologies for any confusion.  My previous posts incorrectly quoted the measured ID as 3.5mm.  It is in fact 3.0mm (which corresponds to the Philmore 206 plug).

[apope]

Have you considered just cutting both cables and splicing the wires from the UPS with the wires leading into official plug ?

I would strongly recommend scraping back the insulation on both first, and then confirming which wire is which voltage, but a couple of Wago in line connectors would make the join easy.

[JB2016]

@apope   There could be a problem if in future the Hub develops a fault and has to be returned to BT.  They might insist on the return of the power supply, and if so they might query the unauthorised modification.   I did manage to obtain a working Smart Hub 2 with power supply from a well-known auction website for under £12, so your suggested solution has already been implemented using the cable from the spare power supply. 

I don't see a need to pare the insulation carefully before cutting.   If the polarity of the output is unknown then it will have to be confirmed by measurement (now what was that trick with a sliced potato?).  Also, the twin flex has a tracer colour on one core, but to be certain a  resistance measurment between each pole of the barrel connector and tails of its attached cable will confirm  things.

I would NOT connect the UPS output in parallel with the wall-wart power supply.  The BT power supply is 12 V;  a typical UPS using lead-acid battery is 13.8V.  

More information on the power requirements of the Smart Hub 2 here:  https://bt-digital-voice.blogspot.com/

[apope]

Fair point about returns.

Maybe we use different terminology, but I said to cut both cables and splice them, which is not the same as wiring them in parallel.

As far as testing, I often make mistakes and find a bit of paranoia goes a long way to avoid blowing things up 🙂