Re: [time-nuts] [volt-nuts] Safe power-up. was (Solartron 7075 ...)
Hmmm. 99% of the time I just plug things in and see what happens. That's what they were designed to do. If something pops I fix it from there. If a fuse keeps blowing I use the light bulb in series trick. On older tube gear I do softly bring it up with the variable autotransformer (Variac, Powerstat), but that's only really because of the capacitors. Just my 2 cents. I do fix a lot of stuff, though, and don't like to waste time futzing when I don't have to. Weak parts get replaced. If they were likely to fail enough to do so when I just plug something in, they need replacing anyway. On 10/11/2011 1:14 AM, David J Taylor wrote: The proper use of the variact's output voltage has a learning curve, because equipment with switchers behave differently than things with linearly supplies ws Warren, It's likely Variac you mean, not variact http://en.wikipedia.org/wiki/Variac#Variable_autotransformers Cheers, David ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [volt-nuts] Safe power-up. was (Solartron 7075 ...)
Peter Gottlieb nerd at verizon.net wrote: 99% of the time I just plug things in and see what happens. I do fix a lot of stuff, though, Hmmm, I have to wonder if there is more than a casual cause and effect relationship between those two statements. I've seen a strong relationship between the wasted time spent fixing extra things that where fried unnecessary, with how careful one is at initial turn on. Monitoring the wattage, using a Kill-A-Watt meter when turning on Old things can save 'futzing time' in the long run. And the most time saving thing I've found besides apply power and throw it out if there is smoke or nothing, is to do a complete visual inspection inside, to insure things are still the way they where designed to be, BEFORE applying any power. Yes Variac, My spell checker thanks you for teaching it the correct spelling. I find it one of the more useful pieces of test equipipment when checking/modifying things to get max Nut-Precision from them. If changing the line voltage or the temperature a little causes ANY measurable effect on performance, then for me, it's time to change something and made it better, which can often be done with just simple changes (and a lot of futzing time). ws Peter Gottlieb nerd at verizon.net Hmmm. 99% of the time I just plug things in and see what happens. That's what they were designed to do. If something pops I fix it from there. If a fuse keeps blowing I use the light bulb in series trick. On older tube gear I do softly bring it up with the variable autotransformer (Variac, Powerstat), but that's only really because of the capacitors. Just my 2 cents. I do fix a lot of stuff, though, and don't like to waste time futzing when I don't have to. Weak parts get replaced. If they were likely to fail enough to do so when I just plug something in, they need replacing anyway. ** On 10/11/2011 1:14 AM, David J Taylor wrote: The proper use of the variact's output voltage has a learning curve, because equipment with switchers behave differently than things with linearly supplies ws Warren, It's likely Variac you mean, not variact http://en.wikipedia.org/wiki/Variac#Variable_autotransformers Cheers, David ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [volt-nuts] Safe power-up. was (Solartron 7075 ...)
I don't plug ANYTHING new to me, directly into the line the first time I try it. (especially if it had a blown fuse) Here is the solution that I use for a universal, general purpose, tester for Old (and new) equipment. This is a great tool that can be used for trouble things that draw too much current, has shorts, for reforming caps, Testing line voltage sensitivity etc, etc. First time powered up test equipment is powered from: 1) A line voltage rate light bulb in series, starting with a low wattage and working your way up. The light bulb acts Nonlinear variable dropping resistor, which act like a current limit and will limit the max current to a safe value but still have minimum effect at lower currents due to it's Hi TC. 2) The voltage to the Light bulb comes which from adjustable variact. The voltage rise and the Time at each voltage setting is a learned function and depends on what is being tested. If you're in a hurry, set it to the nominal line output and flip the switch. The rest of the stuff will still provide protection. 3) The Variact is plugged into a KillAwatt meter Used to constantly monitor the power, If it shows too much power is being used, ... Well don't let it do that.. 4) The Kill-a-W is plugged into a solatron 1 to 1 line regulating transformer. My Line regulating Solitron has the very desirable built in characteristic that it goes into a saturation mode that limits the max output power if overloaded If not overloaded, it outputs a constant voltage. 5) Have a few resetable and/or standard fuses in there to be over safe. The proper use of the variact's output voltage has a learning curve, because equipment with switchers behave differently than things with linearly supplies ws * Hi, I picked up a dead 7075 recently, I found that the fuseholder was not making contact with the fuse, fixed that fault and now the PSU area was making a fizzing noise. I disconnected the mains straight away. I presume I need to reform the main capacitor with a dropper resistor. Is 33k a suitable value, or should it be done at a lower current than that? Regards, M K ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [volt-nuts] Safe power-up. was (Solartron 7075 ...)
In message 4EF131EAEF2E45BA8C7658C73574525B@Warcon28Gz, WarrenS writes: I don't plug ANYTHING new to me, directly into the line the first time I try it. (especially if it had a blown fuse) Here is the solution that I use for a universal, general purpose, tester for Old (and new) equipment. That procedure is fine for linear power-supplies, but not resonably modern switch-modes. In particular, anything that has PFC correction is not going to respond too well to variable voltage like that. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [volt-nuts] Safe power-up. was (Solartron 7075 ...)
Power factor correction power supplies has not been a BIG problem with my OLD recycled equipment. I tried to Cover that case in my end note, With switchers, turn the variact to normal and use the other safety features and a big enough light bulb to keep from blowing it all up if something is wrong. ws * Poul-Henning Kamp phk at phk.freebsd.dk In message WarrenS writes: I don't plug ANYTHING new to me, directly into the line the first time I try it. (especially if it had a blown fuse) Here is the solution that I use for a universal, general purpose, tester for Old (and new) equipment. That procedure is fine for linear power-supplies, but not resonably modern switch-modes. In particular, anything that has PFC correction is not going to respond too well to variable voltage like that. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 *** I don't plug ANYTHING new to me, directly into the line the first time I try it. (especially if it had a blown fuse) Here is the solution that I use for a universal, general purpose, tester for Old (and new) equipment. This is a great tool that can be used for trouble things that draw too much current, has shorts, for reforming caps, Testing line voltage sensitivity etc, etc. First time powered up test equipment is powered from: 1) A line voltage rate light bulb in series, starting with a low wattage and working your way up. The light bulb acts Nonlinear variable dropping resistor, which act like a current limit and will limit the max current to a safe value but still have minimum effect at lower currents due to it's Hi TC. 2) The voltage to the Light bulb comes which from adjustable variact. The voltage rise and the Time at each voltage setting is a learned function and depends on what is being tested. If you're in a hurry, set it to the nominal line output and flip the switch. The rest of the stuff will still provide protection. 3) The Variact is plugged into a KillAwatt meter Used to constantly monitor the power, If it shows too much power is being used, ... Well don't let it do that.. 4) The Kill-a-W is plugged into a solatron 1 to 1 line regulating transformer. My Line regulating Solitron has the very desirable built in characteristic that it goes into a saturation mode that limits the max output power if overloaded If not overloaded, it outputs a constant voltage. 5) Have a few resetable and/or standard fuses in there to be over safe. The proper use of the variact's output voltage has a learning curve, because equipment with switchers behave differently than things with linearly supplies ws * ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [volt-nuts] Safe power-up. was (Solartron 7075 ...)
The proper use of the variact's output voltage has a learning curve, because equipment with switchers behave differently than things with linearly supplies ws Warren, It's likely Variac you mean, not variact http://en.wikipedia.org/wiki/Variac#Variable_autotransformers Cheers, David -- SatSignal software - quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
