[neonixie-l] Re: 555 power supply not working
| On Nov 18, 3:31 pm, Imbanon wrote:
|
| I can't test the inductors, but they should be 100uH, 1watt max
| The diodes are UF4004. I suppose they should work..
|
| Can I use some other inductor, like 220uH?
Are using the parts provided by that kit, or are you just using the
schematic ? This is very important for us to know !
Not all inductors are the are same. 1W ?. That's not a typical
inductor rating. Its usually current (amps, milliamps), for maximum DC
current, and/or maximum saturation current. A supply like this should
be able to handle 500mA (half amp), at the very minimum. Any old pile
of crap from your junk bin just won't do.
Make sure its a UF4004, and not to be confused with a 1N4004. The "UF"
means its an "ultra fast" switching rectifier, in the ballpark of 50
to 100nS (10^-9sec). A 1N4004 ("jelly bean" rectifier) switches much
slower by orders of magnitude. An "order of magnitude" is equal to
10x, 2 orders = 100x, ...
The inductance isn't super critical. What is critical, is that it can
handle the current. Use power inductors.
If you have a scope, test the frequency first. Just hook up the 555,
but leave off the FET and coil, and the feedback parts going back to
pin-5. Leave pin-5 disconnected from everything. Turn it ON, and check
the frequency at pin-3. It calculates to 31KHz, with the schematic's
part values. See if its in the ballpark of 30KHz (20KHz to 40KHz). If
one of those parts is too big, then the frequency will be too low, the
symptoms you describe will happen..
--
You received this message because you are subscribed to the Google Groups
"neonixie-l" group.
To post to this group, send an email to neonixie-l@googlegroups.com.
To unsubscribe from this group, send email to
neonixie-l+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] David makes Popular Science!
Thanks Jim! From: J Forbes To: neonixie-l Sent: Friday, November 18, 2011 8:13 AM Subject: Re: [neonixie-l] David makes Popular Science! The article is online for those who are out of reach of a print copy http://www.popsci.com/diy/article/2011-11/you-built-what-wearable-led-television Jim -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. 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 neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: 555 power supply not working
I just noticed this bit: 'I left it powered, to see the diode smoking next.' If the mosfet was fried before then, the diode should just have been sitting there with nothing to do. I assume it's not connected to the rest of the clock?. Power it up with a 15R series resistor, no mosfet and come back with some voltages. Tony. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] David makes Popular Science!
State of the art. -Sture - Original Message - From: "J Forbes" To: "neonixie-l" Sent: Friday, November 18, 2011 5:13 PM Subject: Re: [neonixie-l] David makes Popular Science! The article is online for those who are out of reach of a print copy http://www.popsci.com/diy/article/2011-11/you-built-what-wearable-led-television Jim -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. 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 neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: 555 power supply not working
First of all I'd go back to using a 10-15 ohm resistor in series with the 12v supply, it will still work and produce 180-200v out for test purposes. Don't bother putting another mosfet in just yet, you need to fid out why it's being fried first. Probably either the mark/space ratio is too long or it's being driven on permanently. What's the DC voltage on pin 3?. You could try connecting one pin of a small cap, maybe .1u to pin 3 and connecting your meter probe to the other pin, if it's oscillating you should get a reading therough the capacitor. Or try a cheap AM radio next to it, you may pick up harmonics. I would check around the feedback circuit and Q2, beyond that you really need a scope to see what the gate drive looks like. It could be very long rise/fall times though if they're failing almost instantly it's probably just the 555 output is stuck high. Tony. On Nov 18, 11:31 pm, Imbanon wrote: > Just tested my FETs. I have 2 new in working order, the other 3 are as > good as a broken nixie. Now I'm afraid of using them, they are my last > x) > > I can't test the inductors, but they should be 100uH, 1watt max. I > can't test them, nor do they have any markings on them. Just plain > black cover. > The diodes are UF4004. I suppose they should work.. > > Can I use some other inductor, like 220uH? > Also, how do I check if my 555 is oscillating without an oscilloscope? > > Thanks! > > On Nov 18, 10:29 pm, Quixotic Nixotic > wrote: > > > > > > > > > I've made up dozens of these supplies in all kinds of layout > > configurations and have found them to be bomb-proof. In fact I have > > never had a failure yet, they work every time. The circuit will work > > without the snubber R6/C3. > > > There must be some simple answer to your problem. It seems to me as > > if the 555 might not be doing any switching, or doing it incorrectly. > > Or as you say the FET is not all it's cracked up to be, or the diode > > is not fast enough. Check the value and rating of your inductor. > > > The FET should not get too hot. Usually it will run cool enough for > > you to hold it. > > > John S > > > On 18 Nov 2011, at 19:43, Imbanon wrote: > > > > Hi all. > > > > Yeah, another thread about this supply..http://www.ledsales.com.au/ > > > kits/nixie_supply.pdf > > > I know I could and should have made that Maxim power supply, but I > > > didn't. So now I'm stuck fixing this with loads of spare parts I've > > > got... except for the FETs.. > > > > Anyways, the supply isn't working. The first one I made worked just > > > fine for 15 minutes, powering 6 IN-14 at 170 volts (multiplexed). Then > > > I set it to 200 volts (to get RMS of 2mA), which worked for 5 minutes, > > > and then smoked and failed. > > > I made another on a quick PCB, which just smoked immediately when I > > > switched it on. The same thing happened to the newest, breadboarded > > > one. > > > The MOSFET seems to overheat instantly and smoke out. Having nothing > > > to lose (except the molten hole in the breadboard), I left it powered, > > > to see the diode smoking next. Aparently, its still in working order > > > (so says the multimeter). > > > Heat sinking FET only makes it last longer in not working state before > > > it smokes. > > > > I tried replacing inductors, 555s, diodes, transistors.. > > > What the F**K do I do people? Losing my head here! > > > > And yeah, I'm powering it at 12 volts, tried 5. Output is always 3-6 > > > volts. > > > > Thank you for any help provided! > > > Imbanon > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "neonixie-l" group. > > > To post to this group, send an email to neonixie-l@googlegroups.com. > > > To unsubscribe from this group, send email to neonixie-l > > > +unsubscr...@googlegroups.com. > > > For more options, visit this group athttp://groups.google.com/ > > > group/neonixie-l?hl=en-GB. > > >  > > > JS Design > > 54 Brambledown Road > > Wallington > > Surrey > > SM6 0TF > > > T+F +44 (0)20 8773 4779www.jsdesign.co.uk -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] Re: 555 power supply not working
If you're going to make a hobby out of electronics, buy an oscilloscope. It doesn't need to be fast. I use a dual-channel tektronix 100mhz scope that was built in the 80's. There are even PC based storage scopes now. -Adam On 11/18/2011 3:31 PM, Imbanon wrote: Also, how do I check if my 555 is oscillating without an oscilloscope? Thanks! -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: 555 power supply not working
Just tested my FETs. I have 2 new in working order, the other 3 are as good as a broken nixie. Now I'm afraid of using them, they are my last x) I can't test the inductors, but they should be 100uH, 1watt max. I can't test them, nor do they have any markings on them. Just plain black cover. The diodes are UF4004. I suppose they should work.. Can I use some other inductor, like 220uH? Also, how do I check if my 555 is oscillating without an oscilloscope? Thanks! On Nov 18, 10:29 pm, Quixotic Nixotic wrote: > I've made up dozens of these supplies in all kinds of layout > configurations and have found them to be bomb-proof. In fact I have > never had a failure yet, they work every time. The circuit will work > without the snubber R6/C3. > > There must be some simple answer to your problem. It seems to me as > if the 555 might not be doing any switching, or doing it incorrectly. > Or as you say the FET is not all it's cracked up to be, or the diode > is not fast enough. Check the value and rating of your inductor. > > The FET should not get too hot. Usually it will run cool enough for > you to hold it. > > John S > > On 18 Nov 2011, at 19:43, Imbanon wrote: > > > > > > > > > > > Hi all. > > > Yeah, another thread about this supply..http://www.ledsales.com.au/ > > kits/nixie_supply.pdf > > I know I could and should have made that Maxim power supply, but I > > didn't. So now I'm stuck fixing this with loads of spare parts I've > > got... except for the FETs.. > > > Anyways, the supply isn't working. The first one I made worked just > > fine for 15 minutes, powering 6 IN-14 at 170 volts (multiplexed). Then > > I set it to 200 volts (to get RMS of 2mA), which worked for 5 minutes, > > and then smoked and failed. > > I made another on a quick PCB, which just smoked immediately when I > > switched it on. The same thing happened to the newest, breadboarded > > one. > > The MOSFET seems to overheat instantly and smoke out. Having nothing > > to lose (except the molten hole in the breadboard), I left it powered, > > to see the diode smoking next. Aparently, its still in working order > > (so says the multimeter). > > Heat sinking FET only makes it last longer in not working state before > > it smokes. > > > I tried replacing inductors, 555s, diodes, transistors.. > > What the F**K do I do people? Losing my head here! > > > And yeah, I'm powering it at 12 volts, tried 5. Output is always 3-6 > > volts. > > > Thank you for any help provided! > > Imbanon > > > -- > > You received this message because you are subscribed to the Google > > Groups "neonixie-l" group. > > To post to this group, send an email to neonixie-l@googlegroups.com. > > To unsubscribe from this group, send email to neonixie-l > > +unsubscr...@googlegroups.com. > > For more options, visit this group athttp://groups.google.com/ > > group/neonixie-l?hl=en-GB. > >  > > JS Design > 54 Brambledown Road > Wallington > Surrey > SM6 0TF > > T+F +44 (0)20 8773 4779www.jsdesign.co.uk -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] 555 power supply not working
I've made up dozens of these supplies in all kinds of layout configurations and have found them to be bomb-proof. In fact I have never had a failure yet, they work every time. The circuit will work without the snubber R6/C3. There must be some simple answer to your problem. It seems to me as if the 555 might not be doing any switching, or doing it incorrectly. Or as you say the FET is not all it's cracked up to be, or the diode is not fast enough. Check the value and rating of your inductor. The FET should not get too hot. Usually it will run cool enough for you to hold it. John S On 18 Nov 2011, at 19:43, Imbanon wrote: Hi all. Yeah, another thread about this supply.. http://www.ledsales.com.au/ kits/nixie_supply.pdf I know I could and should have made that Maxim power supply, but I didn't. So now I'm stuck fixing this with loads of spare parts I've got... except for the FETs.. Anyways, the supply isn't working. The first one I made worked just fine for 15 minutes, powering 6 IN-14 at 170 volts (multiplexed). Then I set it to 200 volts (to get RMS of 2mA), which worked for 5 minutes, and then smoked and failed. I made another on a quick PCB, which just smoked immediately when I switched it on. The same thing happened to the newest, breadboarded one. The MOSFET seems to overheat instantly and smoke out. Having nothing to lose (except the molten hole in the breadboard), I left it powered, to see the diode smoking next. Aparently, its still in working order (so says the multimeter). Heat sinking FET only makes it last longer in not working state before it smokes. I tried replacing inductors, 555s, diodes, transistors.. What the F**K do I do people? Losing my head here! And yeah, I'm powering it at 12 volts, tried 5. Output is always 3-6 volts. Thank you for any help provided! Imbanon -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l +unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/ group/neonixie-l?hl=en-GB.  JS Design 54 Brambledown Road Wallington Surrey SM6 0TF T+F +44 (0)20 8773 4779 www.jsdesign.co.uk -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB. <>
[neonixie-l] Re: 555 power supply not working
Thanks for a fast reply! As posted, http://www.ledsales.com.au/kits/nixie_supply.pdf I used exactly the same parts, made exactly the same PCB. I really don't know what's wrong with it. I test all my parts before using them (except the 555s, FETs and inductors). All new. Could it be the cheap-chinese factor? I've heard they like to sell fake MOSFETs Thanks a lot Imbanon On Nov 18, 8:55 pm, Per Jensen wrote: > Which kind of FET and Diode are you using ? > > Do you have around 100nF of decoupling directly across the power pins of the > 555 ? > > Gimme a link to the shematic you used. > > // Per. > > On 18/11/2011, at 20.43, Imbanon wrote: > > > > > > > > > Hi all. > > > Yeah, another thread about this > > supply..http://www.ledsales.com.au/kits/nixie_supply.pdf > > I know I could and should have made that Maxim power supply, but I > > didn't. So now I'm stuck fixing this with loads of spare parts I've > > got... except for the FETs.. > > > Anyways, the supply isn't working. The first one I made worked just > > fine for 15 minutes, powering 6 IN-14 at 170 volts (multiplexed). Then > > I set it to 200 volts (to get RMS of 2mA), which worked for 5 minutes, > > and then smoked and failed. > > I made another on a quick PCB, which just smoked immediately when I > > switched it on. The same thing happened to the newest, breadboarded > > one. > > The MOSFET seems to overheat instantly and smoke out. Having nothing > > to lose (except the molten hole in the breadboard), I left it powered, > > to see the diode smoking next. Aparently, its still in working order > > (so says the multimeter). > > Heat sinking FET only makes it last longer in not working state before > > it smokes. > > > I tried replacing inductors, 555s, diodes, transistors.. > > What the F**K do I do people? Losing my head here! > > > And yeah, I'm powering it at 12 volts, tried 5. Output is always 3-6 > > volts. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] 555 power supply not working
Which kind of FET and Diode are you using ? Do you have around 100nF of decoupling directly across the power pins of the 555 ? Gimme a link to the shematic you used. // Per. On 18/11/2011, at 20.43, Imbanon wrote: > Hi all. > > Yeah, another thread about this supply.. > http://www.ledsales.com.au/kits/nixie_supply.pdf > I know I could and should have made that Maxim power supply, but I > didn't. So now I'm stuck fixing this with loads of spare parts I've > got... except for the FETs.. > > Anyways, the supply isn't working. The first one I made worked just > fine for 15 minutes, powering 6 IN-14 at 170 volts (multiplexed). Then > I set it to 200 volts (to get RMS of 2mA), which worked for 5 minutes, > and then smoked and failed. > I made another on a quick PCB, which just smoked immediately when I > switched it on. The same thing happened to the newest, breadboarded > one. > The MOSFET seems to overheat instantly and smoke out. Having nothing > to lose (except the molten hole in the breadboard), I left it powered, > to see the diode smoking next. Aparently, its still in working order > (so says the multimeter). > Heat sinking FET only makes it last longer in not working state before > it smokes. > > I tried replacing inductors, 555s, diodes, transistors.. > What the F**K do I do people? Losing my head here! > > And yeah, I'm powering it at 12 volts, tried 5. Output is always 3-6 > volts. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: David makes Popular Science!
Wow what a crazy idea! Just great. But the cost is just huge :) Congrats! -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] 555 power supply not working
Hi all. Yeah, another thread about this supply.. http://www.ledsales.com.au/kits/nixie_supply.pdf I know I could and should have made that Maxim power supply, but I didn't. So now I'm stuck fixing this with loads of spare parts I've got... except for the FETs.. Anyways, the supply isn't working. The first one I made worked just fine for 15 minutes, powering 6 IN-14 at 170 volts (multiplexed). Then I set it to 200 volts (to get RMS of 2mA), which worked for 5 minutes, and then smoked and failed. I made another on a quick PCB, which just smoked immediately when I switched it on. The same thing happened to the newest, breadboarded one. The MOSFET seems to overheat instantly and smoke out. Having nothing to lose (except the molten hole in the breadboard), I left it powered, to see the diode smoking next. Aparently, its still in working order (so says the multimeter). Heat sinking FET only makes it last longer in not working state before it smokes. I tried replacing inductors, 555s, diodes, transistors.. What the F**K do I do people? Losing my head here! And yeah, I'm powering it at 12 volts, tried 5. Output is always 3-6 volts. Thank you for any help provided! Imbanon -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] David makes Popular Science!
The article is online for those who are out of reach of a print copy http://www.popsci.com/diy/article/2011-11/you-built-what-wearable-led-television Jim -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
