- Gas discharge bulb - 18 Updates
- Amperex M24-302W equivalent? - 2 Updates
- ESR meter trap - 1 Update
| philo <philo@privacy.net>: Feb 05 11:54AM -0600 Because he heard I was good at fixing things, a guy with a silk-screening business asked me to look at one of his lights. It's a backup unit so not crucial, but he said no one in town can fix it and it would cost a fortune to send it back to the factory. He was told that it's old and obsolete and even the factory would probably not be able to repair it anyway. I told him I'd look at it, but there was a good chance it would be ready for the scrap heap when I got done. It had "complex" circuitry and as far as I could tell, it first applied a "lower" voltage to the bulb (perhaps 230 volts). Then after it warmed up, would boost the voltage to 600 or so. I know nothing about gas discharge lights, I was wondering if anyone here has an info. As far as I could tell, they emit a lot of UV. He told me that when he first started his business, he had a home made 500watt halogen light that worked fine...it just took 15 minutes to do a burn and he wanted to do things a bit faster. After I gave up trying to repair it, I removed the bulb and sockets and retrofitted halogen fittings and a 230v 1500 watt bulb. He has not tested it yet, but the thing is too bright to even look at so it should work. But still I'm curious about the gas discharge lamp. It's tubular and has no filament. |
| Terry Schwartz <tschw10117@aol.com>: Feb 05 10:55AM -0800 I don't know anything about your particular bulb, but as far as I do know, most gas-discharge bulbs require an initial high voltage strike to ionize the gas, which can be followed by a lower maintaining voltage. Neon bulbs and nixie tubes work this way -- they become essentially constant voltage zeners once ionized. A series resistor typically provides the current limiting and drops the excess voltage. I think other forms of discharge lamps work in a similar fashion. However, some sort of electronic ballast is used and is more efficient than using a resistor. |
| philo <philo@privacy.net>: Feb 05 01:52PM -0600 On 02/05/2018 12:55 PM, Terry Schwartz wrote: > I don't know anything about your particular bulb, but as far as I do know, most gas-discharge bulbs require an initial high voltage strike to ionize the gas, which can be followed by a lower maintaining voltage. Neon bulbs and nixie tubes work this way -- they become essentially constant voltage zeners once ionized. A series resistor typically provides the current limiting and drops the excess voltage. > I think other forms of discharge lamps work in a similar fashion. However, some sort of electronic ballast is used and is more efficient than using a resistor. Thank you. The best I could do with the unit was to get the bulb to light dimly...maybe equal to a 50 watt incandescent at best. I had no schematic and the wires were a rat's nest. |
| N_Cook <diverse@tcp.co.uk>: Feb 05 07:53PM On 05/02/2018 17:54, philo wrote: > it should work. > But still I'm curious about the gas discharge lamp. > It's tubular and has no filament. Difficult things to test other than by substituting , both ways. Be very aware, the strike voltage is of the order 5,000 volts, repeated until something like full current passage. |
| N_Cook <diverse@tcp.co.uk>: Feb 05 07:57PM Forgot to say, because of the 5KV initially, for lash-up testing with known good supply / known good lamp, you need extra sleeving around the hookup wires. |
| Jon Elson <jmelson@wustl.edu>: Feb 05 02:19PM -0600 philo wrote: > up, would boost the voltage to 600 or so. > I know nothing about gas discharge lights, I was wondering if anyone > here has an info. As far as I could tell, they emit a lot of UV. Are you sure about all these details? From your description, I'm thinking this could be a Mercury short-arc lamp. Check eBay item 201564167114 and see if your bulb looks something like that. If so, it takes a high voltage to strike the arc, and then runs something like 4 A at 60 V or so, for a 200 W lamp. Mercury short-arc lamps (as opposed to Xenon lamps) have a couple of really STRONG UV lines that are good for exposing photosensitive materials used in the screen printing industry. And, WATCH out for your eyes, the UV out of these things can be BRUTAL! ONE minute exposure will give you a blistering sunburn. There are other exposing lights I've seen that had a zig-zag tube like a tiny neon sign lamp. I've never seen the power supply for those. Jon |
| philo <philo@privacy.net>: Feb 05 03:15PM -0600 On 02/05/2018 01:57 PM, N_Cook wrote: > Forgot to say, because of the 5KV initially, for lash-up testing with > known good supply / known good lamp, you need extra sleeving around the > hookup wires. The high voltage was not working...I was getting 600 volts max |
| philo <philo@privacy.net>: Feb 05 03:18PM -0600 On 02/05/2018 02:19 PM, Jon Elson wrote: > There are other exposing lights I've seen that had a zig-zag tube like a > tiny neon sign lamp. I've never seen the power supply for those. > Jon It is not one of those, thank you, I will post a photo later. There is nothing inside that I can see. At any rate, if this halogen lamp works, it will probably be safer |
| tabbypurr@gmail.com: Feb 05 01:42PM -0800 On Monday, 5 February 2018 21:18:17 UTC, philo wrote: > It is not one of those, thank you, I will post a photo later. > There is nothing inside that I can see. > At any rate, if this halogen lamp works, it will probably be safer yeah, we need to know what type of lamp really. Telling us the light colour would be a start, and over how long the brightness increases. NT |
| philo <philo@privacy.net>: Feb 05 04:48PM -0600 > NT Found a part number , it's this https://www.bulbworks.com/light-bulbs/1406-04 It seems to be a 5000 watt lamp |
| tabbypurr@gmail.com: Feb 05 04:01PM -0800 On Monday, 5 February 2018 22:48:44 UTC, philo wrote: > https://www.bulbworks.com/light-bulbs/1406-04 > It seems to be a 5000 watt lamp HID lamps aren't my thing, but I believe they take a huge voltage spike to start. Halogen will give a small fraction of the output at that wavelength, increasing process times hugely. NT |
| philo <philo@privacy.net>: Feb 05 06:08PM -0600 > NT He said that it could do a burn in a minute or two but he does not need to go that fast. He is hoping to do it in less than 15 minutes...so I will have to wait for him to test it to see if it works at all. Thank you |
| "tom" <tmiller11147@verizon.net>: Feb 05 07:21PM -0500 "philo" <philo@privacy.net> wrote in message news:p5armk$olu$1@dont-email.me... > go that fast. He is hoping to do it in less than 15 minutes...so I will > have to wait for him to test it to see if it works at all. > Thank you Be very careful with that lamp. They are under very high pressure and can explode if dropped or scratched. |
| John-Del <ohger1s@gmail.com>: Feb 05 04:35PM -0800 On Monday, February 5, 2018 at 7:08:55 PM UTC-5, philo wrote: > to go that fast. He is hoping to do it in less than 15 minutes...so I > will have to wait for him to test it to see if it works at all. > Thank you If it doesn't work, I'd check all those alternate part numbers in your link and see if any of those lamps could be matched to a ballast. You might be able to source a stand alone board. Or email companies like Ushio and see if they can help. |
| philo <philo@privacy.net>: Feb 05 07:13PM -0600 On 02/05/2018 06:21 PM, tom wrote: Thanks for the warning, I'm going to wrap it carefully and put it in a safe place. |
| philo <philo@privacy.net>: Feb 05 07:15PM -0600 On 02/05/2018 06:35 PM, John-Del wrote: >> will have to wait for him to test it to see if it works at all. >> Thank you > If it doesn't work, I'd check all those alternate part numbers in your link and see if any of those lamps could be matched to a ballast. You might be able to source a stand alone board. Or email companies like Ushio and see if they can help. OK but I hope the halogen lamp I have in there does the job. |
| Fox's Mercantile <jdangus@att.net>: Feb 05 08:54PM -0600 On 2/5/18 6:21 PM, tom wrote: > Be very careful with that lamp. They are under very high pressure and can > explode if dropped or scratched. Note also numerous warnings about "DO NOT TOUCH" Finger oils on the bulb can cause catastrophic failures. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| philo <philo@privacy.net>: Feb 06 09:03AM -0600 On 02/05/2018 08:54 PM, Fox's Mercantile wrote: >> explode if dropped or scratched. > Note also numerous warnings about "DO NOT TOUCH" > Finger oils on the bulb can cause catastrophic failures. Thanks That much I knew, I wore clean cotton gloves. |
| frank <frank@invalid.net>: Feb 05 06:55PM > Can you get a wire in between the flyback coil and core ? If so you just > make your own winding that is totally floating. Start with one turn and work > your way up until the filament is bright enough. never mind, it wasn't a short circuit in the CRT. It was me supposing the cathode should cutoff at 0V, instead it was supposed to cutoff at something like 20-30V. One amplifier stage was bad, a 2N2369 tested good on a diode probe (both junctions!!) and it was not amplifying at all, just passing the signal through the base-collector junction, so not inverting it. The end signal at the catode was "upside down". Replacing the 2N2369 cured the monitor (well, geometry isn't the best, but I won't mess with it). > display. The less the better as it will result in the longest cathode life. > The cathode has already been abused putting out more current than was ever > intended. I have scopes and other test instruments (like a few true RMS meters) and I'm glad I just needed the scope to find the bad stage, once I realized I needed a positive voltage to cutoff the cathode. The first common-emitter stage didn't invert the signal, so it was easy to spot. This monitor is 41 years old by the way :) Thanks Frank |
| jurb6006@gmail.com: Feb 05 02:17PM -0800 >"One amplifier stage was bad, a 2N2369 tested good on a diode probe (both junctions!!) and it was not amplifying at all" i have had them go bad like that a few times but they were not passing any signal. Yours probably had a leakage path. |
| Chuck <ch@dejanews.net>: Feb 05 12:46PM -0600 On Sun, 4 Feb 2018 13:32:17 -0800 (PST), John-Del <ohger1s@gmail.com> wrote: >> axial caps checked good for ESR with the Bob Parker meter in circuit >> but were faulty. >How did they check out of circuit with the Parker meter? Bad. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
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