Grahame, Nice idea that clock !
My little penny: Cant you vind brass end-caps for the tube? Then you only need to make a vieuwing hole at the front end, evenually equiped with a contrast filter (preferrably polaroid foil, or may be the glass of an old photographic polaroid filter). That's quick made. eric -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Grahame Marsh Sent: donderdag 8 maart 2012 15:08 To: [email protected] Subject: Re: [neonixie-l] Re: Yet another scope clock On 08/03/2012 11:32, John Rehwinkel wrote: > I'd be tempted to make an old A-scope style radar display with a few > lines of shark-fin looking pips (hours, minutes, seconds), and have > the pips slowly meander across the screen. A few index marks would > make it easier to read. I don't know how hard that would be to code > up, but the existing displays cover a lot of ground, so I'm guessing > it would be feasible. A-Scope: Horizontal traversing pips/triangles, off a horiziontal line, taking (1 second,) 1 minute, 1 hour, 12/24 hours to go L/R or R/L - easy! I'll code it when I have the pingpong clock finished. > I'm hoping to get a look at the code soon, idiosyncratic or not. I > have a fondness for strange real-time code. I'll try to put the current draft code up tonight, so look back in about 24 hrs and the code.zip file should be there. Head straight to crt.c and .h as that is where all the low level driver stuff is. Then look at say, klingon.c and .h, and you'll see a simple case of how the lowlevel stuff is called (each clock face lives in its own .c and .h files so it should be easy to find an individual clock face's code). Then the main code (sc01.c) where the clock face being displayed is called under 20mS interrupt call. (BTW the 20mS is mains derived which I hoped would avoid the display "swimming" in an external magnetic field as the clock has no shielding. So far no problems.) > They don't? What are you using as rectifiers? I can imagine a 50Hz supply with 5642s as rectifiers, but that would involve adding quite a few filament windings to the power transformer. Yes, I was being a bit loose, just 1N4004, semiconductors of course. No chips or MOSFETS to fry is what I meant :o) > > Which reminds me, the article mentioned adding a heater winding, but I didn't find a description of how it was implemented. The heater winding details are lost on the schematic. Basically about 120 turns for the toroidal transformer I used. I wind on a measured length (1m typically) and count the turns and load it to 0.3A and measure the voltage. I discard this length. This method gives me the turns per volt and the total length of the wire to wind on. I add about 10% more and then trim back to get the 6.3V. I was thinking of putting a bit of text on the webpage about it. The extra winding is "easy" on a toroid and avoids a second transformer or special, so is cheap. I used multicore hook up wire that has a > 1kV insulation (PVC) and a couple of amps capacity so is overkill for the duty. > I think brass on both ends would look really sharp. I'd be tempted to make a slide out light shade as well, either a hood like a traffic signal, or a tube like the old Waterman pocket scopes. Not that it's necessary, but it's another fun thing to fiddle with, if you actually want peoples' fingers near the CRT. Only, I'm trying to close the project down to get on with the next! The brass and copper is lacquered to avoid finger markers appearing - the copper tube forms a natural handle to pick it up with unfortunately. The light shield is a good idea, for this tube in particular, as it has no separate focus anode - the brightness control is both brightness and focus, and the best focus is when the tube is not bright. > I love the Latin markings too. Fiat lux, indeed! My wife's contribution. Getting her to contribute to projects is my technique (not always successful) that permit projects to leave the workshop and enter the house. Thanks for the feedback - as always very good with this group Cheers Grahame -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
