"Tim Williams" <tiwill@seventransistorlabs.com> wrote in news:ppsf6u$970$1 @dont-email.me:> And yeah, if you have too much thermal mass for this to work, you need a > preheater. >That was his entire beef. Hard to desolder... preheat was the suggestion a couple of us gave.
guard ring?
Started by ●October 12, 2018
Reply by ●October 13, 20182018-10-13
Reply by ●October 14, 20182018-10-14
John Larkin wrote:> > > I'm still iterating on my high-voltage pulse generator. Rev C looks > very good. I've been pushing it up voltage and frequency (like, 1200 > volts and 4 MHz) and seeing what parts fry, and working on them. > > I have a dpak schottky diode in a sort of snubber place. According to > Spice, it shouldn't get too hot, and it's soldered to all sorts of > copper pours and thermal vias and stuff. It's an SBRD10200 and it's > frying. I happened to have some smaller, lower current diodes around, > UPS5100E3, which is a sawed-off sub-dpak thing. I figured I might > squeeze in two of those in parallel... but just one runs cool. > > https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1 > > Weird. I'm guessing that the big one has a p-n guard ring that makes > it have reverse recovery current right after a big forward current > spike. Data sheets never talk about that. > > I heat sinked things too well, so it's a bear to desolder/resolder. > > https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1Error (500) Something went wrong. Don't worry, your files are still safe and the Dropboxers have been notified. Check out our Help Center and forums for help, or head back to home.> >
Reply by ●October 14, 20182018-10-14
On Sat, 13 Oct 2018 22:45:41 -0700, Robert Baer <robertbaer@localnet.com> wrote:>John Larkin wrote: >> >> >> I'm still iterating on my high-voltage pulse generator. Rev C looks >> very good. I've been pushing it up voltage and frequency (like, 1200 >> volts and 4 MHz) and seeing what parts fry, and working on them. >> >> I have a dpak schottky diode in a sort of snubber place. According to >> Spice, it shouldn't get too hot, and it's soldered to all sorts of >> copper pours and thermal vias and stuff. It's an SBRD10200 and it's >> frying. I happened to have some smaller, lower current diodes around, >> UPS5100E3, which is a sawed-off sub-dpak thing. I figured I might >> squeeze in two of those in parallel... but just one runs cool. >> >> https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1 >> >> Weird. I'm guessing that the big one has a p-n guard ring that makes >> it have reverse recovery current right after a big forward current >> spike. Data sheets never talk about that. >> >> I heat sinked things too well, so it's a bear to desolder/resolder. >> >> https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1 >Error (500) >Something went wrong. Don't worry, your files are still safe and the >Dropboxers have been notified. Check out our Help Center and forums for >help, or head back to home.Looks fine to me. Anybody else having problems seeing my links? Some companies don't allow their employees to see Dropbox, or to receive verious email attatchments. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●October 14, 20182018-10-14
On 10/14/2018 11:44 AM, John Larkin wrote:> On Sat, 13 Oct 2018 22:45:41 -0700, Robert Baer > <robertbaer@localnet.com> wrote: > >> John Larkin wrote: >>> >>> >>> I'm still iterating on my high-voltage pulse generator. Rev C looks >>> very good. I've been pushing it up voltage and frequency (like, 1200 >>> volts and 4 MHz) and seeing what parts fry, and working on them. >>> >>> I have a dpak schottky diode in a sort of snubber place. According to >>> Spice, it shouldn't get too hot, and it's soldered to all sorts of >>> copper pours and thermal vias and stuff. It's an SBRD10200 and it's >>> frying. I happened to have some smaller, lower current diodes around, >>> UPS5100E3, which is a sawed-off sub-dpak thing. I figured I might >>> squeeze in two of those in parallel... but just one runs cool. >>> >>> https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1 >>> >>> Weird. I'm guessing that the big one has a p-n guard ring that makes >>> it have reverse recovery current right after a big forward current >>> spike. Data sheets never talk about that. >>> >>> I heat sinked things too well, so it's a bear to desolder/resolder. >>> >>> https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1 >> Error (500) >> Something went wrong. Don't worry, your files are still safe and the >> Dropboxers have been notified. Check out our Help Center and forums for >> help, or head back to home. > > Looks fine to me. Anybody else having problems seeing my links? > > Some companies don't allow their employees to see Dropbox, or to > receive verious email attatchments.No problem at all here. Nice photos.
Reply by ●October 14, 20182018-10-14
On Sun, 14 Oct 2018 12:45:49 -0500, John S <Sophi.2@invalid.org> wrote:>On 10/14/2018 11:44 AM, John Larkin wrote: >> On Sat, 13 Oct 2018 22:45:41 -0700, Robert Baer >> <robertbaer@localnet.com> wrote: >> >>> John Larkin wrote: >>>> >>>> >>>> I'm still iterating on my high-voltage pulse generator. Rev C looks >>>> very good. I've been pushing it up voltage and frequency (like, 1200 >>>> volts and 4 MHz) and seeing what parts fry, and working on them. >>>> >>>> I have a dpak schottky diode in a sort of snubber place. According to >>>> Spice, it shouldn't get too hot, and it's soldered to all sorts of >>>> copper pours and thermal vias and stuff. It's an SBRD10200 and it's >>>> frying. I happened to have some smaller, lower current diodes around, >>>> UPS5100E3, which is a sawed-off sub-dpak thing. I figured I might >>>> squeeze in two of those in parallel... but just one runs cool. >>>> >>>> https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1 >>>> >>>> Weird. I'm guessing that the big one has a p-n guard ring that makes >>>> it have reverse recovery current right after a big forward current >>>> spike. Data sheets never talk about that. >>>> >>>> I heat sinked things too well, so it's a bear to desolder/resolder. >>>> >>>> https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1 >>> Error (500) >>> Something went wrong. Don't worry, your files are still safe and the >>> Dropboxers have been notified. Check out our Help Center and forums for >>> help, or head back to home. >> >> Looks fine to me. Anybody else having problems seeing my links? >> >> Some companies don't allow their employees to see Dropbox, or to >> receive verious email attatchments. > >No problem at all here. Nice photos. >Same here. No problems.
Reply by ●October 14, 20182018-10-14
On 2018-10-14, John Larkin <jjlarkin@highlandtechnology.com> wrote:> On Sat, 13 Oct 2018 22:45:41 -0700, Robert Baer ><robertbaer@localnet.com> wrote:>>> https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1>>> https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1>>Error (500) >>Something went wrong. Don't worry, your files are still safe and the >>Dropboxers have been notified. Check out our Help Center and forums for >>help, or head back to home. > > Looks fine to me. Anybody else having problems seeing my links?Sometimes they don't work. Retrying later usually works. Those are working now. -- Notsodium is mined on the banks of denial.
Reply by ●October 14, 20182018-10-14
Jasen Betts <jasen@xnet.co.nz> wrote in news:pq05cm$lfo$1@gonzo.alcatraz:> Sometimes they don't work. Retrying later usually works. Those are > working now. >Are you still on a POTS connection and a modem somewhere in backwoods hellville?
Reply by ●October 14, 20182018-10-14
On Fri, 12 Oct 2018 14:01:14 -0700, John Larkin <jjlarkin@highland_snip_technology.com> wrote:> > >I'm still iterating on my high-voltage pulse generator. Rev C looks >very good. I've been pushing it up voltage and frequency (like, 1200 >volts and 4 MHz) and seeing what parts fry, and working on them. > >I have a dpak schottky diode in a sort of snubber place. According to >Spice, it shouldn't get too hot, and it's soldered to all sorts of >copper pours and thermal vias and stuff. It's an SBRD10200 and it's >frying. I happened to have some smaller, lower current diodes around, >UPS5100E3, which is a sawed-off sub-dpak thing. I figured I might >squeeze in two of those in parallel... but just one runs cool. > >https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1 > >Weird. I'm guessing that the big one has a p-n guard ring that makes >it have reverse recovery current right after a big forward current >spike. Data sheets never talk about that. > >I heat sinked things too well, so it's a bear to desolder/resolder. > >https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1Replacing three schottky diodes with the cute little Microsemi parts helped my pulse generator efficiency a lot. They also solder into an SMB diode footprint, with some care to not short out. My circuit still isn't as efficient as the Spice sim, so I've been prowling around with our FLIR imager to see where the heat is. Surprisingly (to me) at 1KV and 4 MHz pulse rate, the Phoenix output terminal block is hot. I ripped out the metal bits from the unused center terminal, and it really cooled off. https://www.dropbox.com/s/ogiwi79ovipishe/T850_Phoenix.JPG?raw=1 Power consumption dropped by 3.4 watts. I suppose the ham radio RF power guys already knew about stuff like this; I'm still learning. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●October 14, 20182018-10-14
On Sunday, October 14, 2018 at 9:44:25 AM UTC-7, John Larkin wrote:> On Sat, 13 Oct 2018 22:45:41 -0700, Robert Baer > <robertbaer@localnet.com> wrote: > > >John Larkin wrote: > >> > >> > >> I'm still iterating on my high-voltage pulse generator. Rev C looks > >> very good. I've been pushing it up voltage and frequency (like, 1200 > >> volts and 4 MHz) and seeing what parts fry, and working on them. > >> > >> I have a dpak schottky diode in a sort of snubber place. According to > >> Spice, it shouldn't get too hot, and it's soldered to all sorts of > >> copper pours and thermal vias and stuff. It's an SBRD10200 and it's > >> frying. I happened to have some smaller, lower current diodes around, > >> UPS5100E3, which is a sawed-off sub-dpak thing. I figured I might > >> squeeze in two of those in parallel... but just one runs cool. > >> > >> https://www.dropbox.com/s/6zv36c4d6v7dsbn/Two_Diodes.JPG?raw=1 > >> > >> Weird. I'm guessing that the big one has a p-n guard ring that makes > >> it have reverse recovery current right after a big forward current > >> spike. Data sheets never talk about that. > >> > >> I heat sinked things too well, so it's a bear to desolder/resolder.Dremel?> >> https://www.dropbox.com/s/bg0399wzzi4k3ze/T850C_D1_Kluge.jpg?raw=1 > >Error (500) > >Something went wrong. Don't worry, your files are still safe and the > >Dropboxers have been notified. Check out our Help Center and forums for > >help, or head back to home. > > Looks fine to me. Anybody else having problems seeing my links?Might have been the Great Internet Reset: https://www.networkworld.com/article/3313341/internet/icanns-internet-dns-security-upgrade-apparently-goes-off-without-a-glitch.html It was announced that some ISPs might have issues. Mark L. Fergerson
Reply by ●October 15, 20182018-10-15
On 2018-10-14, DecadentLinuxUserNumeroUno@decadence.org <DecadentLinuxUserNumeroUno@decadence.org> wrote:> Jasen Betts <jasen@xnet.co.nz> wrote in news:pq05cm$lfo$1@gonzo.alcatraz: > >> Sometimes they don't work. Retrying later usually works. Those are >> working now. >> > > Are you still on a POTS connection and a modem somewhere in backwoods > hellville?No. And how the fuck would a POTS connection cause dropbox to fail anyway? sometimes drop box is drop ball. -- Notsodium is mined on the banks of denial.
