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Old Nov 22 2019, 08:54 PM   #5132
Zelandeth
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Join Date: Mar 2013
Location: Milton Keynes
Gender: M
Fan of: Dragonsdawn
Now Reading: Working my way through the whole Pern series
Default Re: What is happening

Quote:
Originally Posted by Hans View Post
So, Zelandeth, you've been fiddling around on the dark side of the Sun :-)
Aye! Spent a couple of hours with my head buried inside it!

-- -- --

Today I picked up a couple of the correct F30WT12 tubes for the lit sign on the Sun 1215.

While T8 tubes physically fit and will work, the electrical specs are quite different. The T12 3' tube dates back to the original set of designs from the earliest days of fluorescent tech, whereas the T8 is a far later design which operates at a far higher voltage but lower current. As such an F30WT8 in this application would be overdriven, running at around 45W rather than the correct 30W, so wouldn't last long.

These however will be perfect. They're hard to find here as this size were never popular in the UK. These are new old stock circa 1993, so goodness knows where they've been hiding since then.



Replacement took all of about 30 seconds.



I remembered to check and clean both the reflector and inside of the diffuser this time. They were distinctly grubby.



Everything back together. You really can't see any difference externally to be honest.



As it's not the sort of equipment a lot of people will have used and it seems to have generated quite a bit of interest I thought I'd try to write up a bit of a guide to the basic startup and configuration of the machine. Figured some of you might find it interesting.

This isn't a full user guide...just a quick run through of the real basics from what I remember of using the one a mate had about 20 years ago and what I've seen messing around with this one.

Hopefully this will demystify all those buttons a bit.

When first powered on the machine shows a message informing you that it has started its warmup phase and gives a countdown (starting from fifteen minutes) to when it will be ready to use.



You can bypass this delay at any point by pressing #, but there's obviously a greater chance of the accuracy of the machine may drift as it warms up. The fifteen minute delay helps ensure that everything is stable before you put it into use.

The # button basically functions as the "next page" control throughout.



At the completion of the countdown, the machine waits for you to press # to continue before it will move on to the self test/calibration screen.



This takes a minute or so to run through...and obviously has a few errors reported in the case of my machine... hopefully these will disappear as time goes on and I work through things.



Next page is the program setup screen where things start to get a little more interesting.



The "set ignition selector" relates to two modes that the ignition side of things can run in. There's a table in the operator's manual telling you which cars which setting should be used with.

This is selected using this button.



Shown above in mode 1, and below in mode 2. Yes, this is a bit of an excuse to show off the flipdot indicators...even if they are a bit grubby at this stage.



"Set 2 or 4 cycle" is asking you to select whether the engine is a two or four stroke. There's a dedicated button for this, which like the ignition selector has an indicator built into the button itself.



Self explanatory really...4 for a four stroke and 2 for a two stroke.



The number of cylinders is then set using the left of the three buttons below. These have different functions in different program modes hence having several legends, it's less confusing than it initially looks.



The selection starts at 0 by default, and pressing the button cycles through 2, 3, 4, 5, 6, 8, 10, 12 then loops back to 2.

The last thing on this section is the timing offset. This is only needed I believe where the car uses a magnetic pickup to fire the ignition, this is usually offset a few degrees before or after TDC. You need to dial this in here.

Pressing "number select" initially changes the sign to + or - to reflect whether the offset is before or after TDC, then "cursor advance" moves to the first digit, with "number select" used to advance the number. This process is repeated until you've dialled in the correct offset.

The screen below is an example which would have been used on my old Saab from memory, you can see the cursor showing which digit is being entered.



Once you have advanced to the last digit it will tell you to press # to the next page. It won't let you proceed if there are things you've missed.



This brings you up to the "Cranking/Pinpoint Tests" page.



This gives you quite a bit of information on what's going on. However this is only half the information it can show you. An additional page is accessible using the "short" button on the control panel. This appears to indicate "short-cut" rather than that it shorts anything out to kill the ignition system or anything.

Here it's shown activated, hence the vivid orange indicator shown.



All of the buttons - even those which are purely momentary - have the indicators in them. Utterly unnecessary, but a nice touch.

This screen gives you some really quite clever diagnostic information.



This shows you the difference in engine speed, starter motor current draw as the engine spins over each cylinder. This can be helpful in showing if one or more cylinders has a significantly lower compression ratio than the others.

You might need to actually stop the engine from starting to get solid data from this test, and there's a control to disable the ignition system labelled as "engine kill."



Pressing this toggles the kill, and when it's enabled a flashing "engine kill" warning is shown on the display to warn the user. Having this feature on hand is obviously useful from a safety perspective as well.

The "Short" button latches, so pressing it again will drop you back to the Cranking/pinpoint Tests page.

Once you're done with that, pressing # will advance you to the main running test page.



This shows you pretty much everything you need to know. The displays look to update pretty rapidly, at least a few times a second. If wanted, you can pause the data on screen with the "Display Hold" button. This is directly below the # button.



When this is enabled a "hold" message flashes at the upper right of the screen to warn the user that live data isn't being shown.

A useful feature of this as well is that in the main screen above, when the display hold control is released, the original data is left in the screen with a new column being put up for the live data. This allows you two "old" readings to be shown along with the live data. This could be really useful if you're making small tweaks and wanting to double check what effect it's had.

The below display shows a "full" page with two columns of held data shown.



The live data is always shown on the leftmost column.

That's as far into the running of this unit as I've gone...but it gives you a basic rundown of how the computer works. Shows how it does a pretty good job of guiding you through everything...which in the mid 80s really wasn't a given!

Probably the most daunting looking controls relate to the scope...though I've never really done enough work with that to be able to talk through it from memory.



The Short button being grouped here rather than with the computer controls is just to keep you on your toes.

I'll try someday to write a bit of a how to for this too...I'll need to learn to drive it a bit better first though.

Likewise some of the advanced features of the computer...there's a whole additional layer in there I think.

For the sake of convenience there's a remote control which duplicates a number of buttons from the front panel to make life easier for the technician. #, Display Hold, Short and Engine Kill being those controls.



The "Print" button would trigger the optional printer. No timestamps or anything, it would just literally print a copy of what's shown on the screen. Sadly I don't have the printer, though I do have the interface card (found in the base cabinet) should I ever come across one.

This has been probably horribly tedious to most of you, but hopefully it's vaguely interesting to you if you're into old tech and want to see what would be happening when you're blindly mashing buttons to see what makes it tick.

If you have any questions please feel free to ask.
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