Pictures of my ZX81 fitted with a RECOM 5V Regulator

Discussions about Sinclair ZX80 and ZX81 Hardware
patters
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Joined: Thu Mar 11, 2021 12:34 pm

Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by patters »

Having seen the photo on page 1 of this thread of a Traco regulator installed upright I soldered mine in like this. That was a mistake. There are two problems. The upper case slopes down just at the edge of where this regulator sits, just enough to prevent the proper mating of the PCB to its standoffs on the upper case. Even with a solder pump I was unable to remove the regulator once I had fitted it.

I tried applying a prying force with a toothpick and walking the iron back and forth over the pins but I could only loosen it and raise it up by about a millimetre. By pushing back I have bent the pins just enough to allow the top case fit, however there is another issue with mounting the Traco directly in the 7805's holes without making some 90 degree supports for it - the tip of the power jack protrudes slightly from its socket when inserted properly. This will push into the Traco with each insertion. Over time this will probably crack its solder joints.

So if you buy a Traco, I'd recommend mounting it on its side as per Mark's initial photos of his RECOM example. For the filtering caps I found that ordering an axial ceramic made it easier to install in the slightly wider spaced holes.
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