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-   -   BT Robin - Answering Machine 202A (https://www.vintage-radio.net/forum/showthread.php?t=132943)

Pellseinydd 11th Jan 2017 12:40 am

BT Robin - Answering Machine 202A
 
Does anyone know what voltage the Plug Top power supply for the BT Robin (Machine ,Answering & Recording No 202A) http://www.britishtelephones.com/ansr202a.htm, introduced in 1985, used?

I've just found one at home (as you do!) but no PSU :(

As usual with a lot of BT equipment, there is no mention on any labels on it, of the required voltage.

Dave Moll 11th Jan 2017 8:42 am

Re: BT Robin - Answering Machine 202A
 
I'll check to see whether the one in my store room has its PSU.

Nickthedentist 11th Jan 2017 10:00 am

Re: BT Robin - Answering Machine 202A
 
This seems to be a common query: https://www.vintage-radio.net/forum/...d.php?p=737483

Dave Moll 11th Jan 2017 8:10 pm

Re: BT Robin - Answering Machine 202A
 
And unfortunately, I am unable to assist as my Robin has no power supply either. More importantly, not only is there no indication of voltage but also what the polarity is of the connector - though the latter can presumably be established by dismantling and looking at the circuitry (which I haven't done).

edit: I see that the point about polarity is also discussed in the referenced thread. Perhaps I should have looked there before replying.

HamishBoxer 12th Jan 2017 11:09 am

Re: BT Robin - Answering Machine 202A
 
I remember or think mine was 18Volts.

PS The worst thing on these is dry joints in abundance

toshiba tony 12th Jan 2017 12:28 pm

Re: BT Robin - Answering Machine 202A
 
Were they not ac. Something rings a bell, just look for the absence of a bridge
(or presence)

AC/HL 12th Jan 2017 3:19 pm

Re: BT Robin - Answering Machine 202A
 
That could be why there aren't any polarity markings?

HamishBoxer 12th Jan 2017 3:59 pm

Re: BT Robin - Answering Machine 202A
 
In that case (AC) there will be a bridge.If I find my psu I will put it up FOC as I certainly dont have that Robin anymore.

Dave Moll 12th Jan 2017 4:58 pm

Re: BT Robin - Answering Machine 202A
 
Quote:

Originally Posted by AC/HL (Post 909203)
That could be why there aren't any polarity markings?

On the other hand, the lack of them could simply be, as with the lack of any voltage indication, that it was simply expected to be run from a supplied PSU - so knowledge of what flowed between them was not considered necessary.

By the way, if the above-mentioned PSU is found, measurement and publication of its output would be useful before it's rehomed.

HamishBoxer 12th Jan 2017 5:15 pm

Re: BT Robin - Answering Machine 202A
 
Will do Dave.

julie_m 12th Jan 2017 6:58 pm

Re: BT Robin - Answering Machine 202A
 
I guess they were concerned that anything but an original PSU might invalidate the BABT approval of the answering machine, so avoided anything (like marking the voltage and polarity) that might encourage users to try substituting their own. Under the right (unlikely, but by no stretch impossible) combination of circumstances, a fault could damage the exchange -- or even other subscribers' equipment.

HamishBoxer 12th Jan 2017 7:28 pm

Re: BT Robin - Answering Machine 202A
 
Good comment Julie.

dseymo1 12th Jan 2017 9:59 pm

Re: BT Robin - Answering Machine 202A
 
In this sort of situation, I usually check the polarity and approximate voltage by examining the electrolytic caps. I then start with perhaps 1/3 of their rated voltage, and slowly wind it up until the thing starts to work properly. Add about 20%, and that will usually do.


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