Building a replacement MTX PSU

About original Memotech hardware.
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wyerd
Posts: 93
Joined: 13 May 2013 23:16
Location: Upstate New York. USA.

Re: Building a replacement MTX PSU

Post by wyerd »

I'm trying to figure out how to connect everything together and at what stage to fit them to and inside the box. Did you do all the soldering outside the box?
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1024MAK
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Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

No. I try to do as much as possible outside the box, as a slight misjudgement when moving a hot soldering iron and you make a mess of either the insulation of a wire you are not working on, or the plastic of the box :twisted:

It does mean you have to think through what you are doing first. Then visualize it in your head. Maybe do a dry fit to confirm. Correct silly mistakes in the plan (make notes if it helps) so that in practice, it goes smoothly (myself having learn the hard way more than once :oops: ).

I forget now the exact order, but the last mains wiring that I did was soldering to the transformer.

Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
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1024MAK
Posts: 758
Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

Okay some external shots:
finished switch, LED and fuseholder.JPG
finished switch, LED and fuseholder.JPG (261.12 KiB) Viewed 8338 times
finished switch, LED and fuseholder 2.JPG
finished switch, LED and fuseholder 2.JPG (237.77 KiB) Viewed 8338 times
Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
User avatar
1024MAK
Posts: 758
Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

Final wiring up of the mains connections and the wiring to the transformer:-
Wiring up the transformer.JPG
Wiring up the transformer.JPG (170.21 KiB) Viewed 8338 times
Wiring up the transformer2.JPG
Wiring up the transformer2.JPG (150.95 KiB) Viewed 8338 times
Wiring up the transformer3.JPG
Wiring up the transformer3.JPG (201.21 KiB) Viewed 8338 times
In the top right corner of this last photo, you can just see the cable tie over the heatshrink of the output cable...

Mark
Last edited by 1024MAK on 23 Jun 2015 23:26, edited 1 time in total.
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
User avatar
1024MAK
Posts: 758
Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

Wiring up the transformer4.JPG
Wiring up the transformer4.JPG (282.63 KiB) Viewed 8337 times
Wiring up the transformer5.JPG
Wiring up the transformer5.JPG (311.98 KiB) Viewed 8337 times
Don't forget the earth connection:
Wiring up the transformer - earth connection.JPG
Wiring up the transformer - earth connection.JPG (97.4 KiB) Viewed 8337 times
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
User avatar
1024MAK
Posts: 758
Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

5A fuseholder and LED inside the case:
5A fuseholder and LED inside the case 1.JPG
5A fuseholder and LED inside the case 1.JPG (210.79 KiB) Viewed 8337 times
Finished IEC mains connector - outside view:
Finished IEC mains connector - outside view.JPG
Finished IEC mains connector - outside view.JPG (162.66 KiB) Viewed 8337 times
Okay, that's all the photos that I have from last year posted up.

Rather silly of me, but the photos I took after these were posted earlier up in this thread here :oops:.

Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
wyerd
Posts: 93
Joined: 13 May 2013 23:16
Location: Upstate New York. USA.

Re: Building a replacement MTX PSU

Post by wyerd »

Mark,

This should be easy, but I can't figure out which terminal on the switch is the input live & neutral and the corresponding outputs. There's noting on the switch itself apart from terminal numbers and the tech PDF doesn't say either.

http://2nxod5497ve018julv28ilzx3fd.wpen ... WR_PPR.pdf
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1024MAK
Posts: 758
Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

Is your switch an illuminated type?

Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
wyerd
Posts: 93
Joined: 13 May 2013 23:16
Location: Upstate New York. USA.

Re: Building a replacement MTX PSU

Post by wyerd »

Yes it is.
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1024MAK
Posts: 758
Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: Building a replacement MTX PSU

Post by 1024MAK »

If you have a look at the pictures in this post (hint: it's the right hand terminal in the picture here) and the following ones, especially this set of pictures you can just make out very thin wires that go from the terminals to the neon. These are the output terminals. It does not normally matter which is live/line and which is neutral. Your switch may be the same.

If this does not help, please post some good pictures of your switch. The PDF you posted does include numbered terminals in one of the diagrams, but the numbers are unreadable because they are so small :twisted:

Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer in Somerset later in the year :D

Not as many MTXs as Dave! :lol:
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