Forums

Junkbox switch for a switcher

Started by bitrex August 22, 2016
I need to throw together a ~150 volt supply at a few 10s of mA to test a 
circuit idea, but I don't have much in the way of MOSFETs in my junk box 
to build a switcher from.

The only high-voltage device I have in stock is a couple Fairchild 
FQP2N60Cs, rated for 600V and 2 amps. That might be a possibility.

I also have some lower voltage power devices, and I'm wondering if there 
would be a way to cascode two of them for a quick hack to make this work 
if I need to. Looks like I have some IRF530s, IRFZ24s, KSC1173 power 
BJT, the PNP equivalent KSA473, some MJE350s (high voltage but too low 
current) and whatever the NPN equivalent is.

Anything I can do with this crap?
On 08/22/2016 01:09 PM, bitrex wrote:
> I need to throw together a ~150 volt supply at a few 10s of mA to test a > circuit idea, but I don't have much in the way of MOSFETs in my junk box > to build a switcher from. > > The only high-voltage device I have in stock is a couple Fairchild > FQP2N60Cs, rated for 600V and 2 amps. That might be a possibility. > > I also have some lower voltage power devices, and I'm wondering if there > would be a way to cascode two of them for a quick hack to make this work > if I need to. Looks like I have some IRF530s, IRFZ24s, KSC1173 power > BJT, the PNP equivalent KSA473, some MJE350s (high voltage but too low > current) and whatever the NPN equivalent is. > > Anything I can do with this crap?
Input is going to be 12 volts, sorry.
On Mon, 22 Aug 2016 13:09:32 -0400, bitrex
<bitrex@de.lete.earthlink.net> wrote:

>I need to throw together a ~150 volt supply at a few 10s of mA to test a >circuit idea, but I don't have much in the way of MOSFETs in my junk box >to build a switcher from. > >The only high-voltage device I have in stock is a couple Fairchild >FQP2N60Cs, rated for 600V and 2 amps. That might be a possibility. > >I also have some lower voltage power devices, and I'm wondering if there >would be a way to cascode two of them for a quick hack to make this work >if I need to. Looks like I have some IRF530s, IRFZ24s, KSC1173 power >BJT, the PNP equivalent KSA473, some MJE350s (high voltage but too low >current) and whatever the NPN equivalent is. > >Anything I can do with this crap?
How about a string of 9 volt batteries? Or rectify the AC line, with some prudent protections. You could make a flyback with the big Fairchilds. You could drive it open-loop from a function generator. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On 08/22/2016 02:23 PM, John Larkin wrote:
> On Mon, 22 Aug 2016 13:09:32 -0400, bitrex > <bitrex@de.lete.earthlink.net> wrote: > >> I need to throw together a ~150 volt supply at a few 10s of mA to test a >> circuit idea, but I don't have much in the way of MOSFETs in my junk box >> to build a switcher from. >> >> The only high-voltage device I have in stock is a couple Fairchild >> FQP2N60Cs, rated for 600V and 2 amps. That might be a possibility. >> >> I also have some lower voltage power devices, and I'm wondering if there >> would be a way to cascode two of them for a quick hack to make this work >> if I need to. Looks like I have some IRF530s, IRFZ24s, KSC1173 power >> BJT, the PNP equivalent KSA473, some MJE350s (high voltage but too low >> current) and whatever the NPN equivalent is. >> >> Anything I can do with this crap? > > How about a string of 9 volt batteries? > > Or rectify the AC line, with some prudent protections. > > You could make a flyback with the big Fairchilds. You could drive it > open-loop from a function generator. > >
Stacking 9 volts would be fun, but it's an expensive way to run a thing if you plan on doing it for any length of time. I don't know if the internal resistance of the string would let me provide say 50 mA. They used to make big 45 volt alkaline batteries; they looked like the 9V form factor but about four times longer. I had a couple maybe 15 years ago, I wonder if anyone makes those anymore. Directly rectifying the line is scary! The flyback with the Fairchild seems like a reasonable option.
Den mandag den 22. august 2016 kl. 21.53.56 UTC+2 skrev bitrex:
> On 08/22/2016 02:23 PM, John Larkin wrote: > > On Mon, 22 Aug 2016 13:09:32 -0400, bitrex > > <bitrex@de.lete.earthlink.net> wrote: > > > >> I need to throw together a ~150 volt supply at a few 10s of mA to test a > >> circuit idea, but I don't have much in the way of MOSFETs in my junk box > >> to build a switcher from. > >> > >> The only high-voltage device I have in stock is a couple Fairchild > >> FQP2N60Cs, rated for 600V and 2 amps. That might be a possibility. > >> > >> I also have some lower voltage power devices, and I'm wondering if there > >> would be a way to cascode two of them for a quick hack to make this work > >> if I need to. Looks like I have some IRF530s, IRFZ24s, KSC1173 power > >> BJT, the PNP equivalent KSA473, some MJE350s (high voltage but too low > >> current) and whatever the NPN equivalent is. > >> > >> Anything I can do with this crap? > > > > How about a string of 9 volt batteries? > > > > Or rectify the AC line, with some prudent protections. > > > > You could make a flyback with the big Fairchilds. You could drive it > > open-loop from a function generator. > > > > > > Stacking 9 volts would be fun, but it's an expensive way to run a thing > if you plan on doing it for any length of time. I don't know if the > internal resistance of the string would let me provide say 50 mA. > > They used to make big 45 volt alkaline batteries; they looked like the > 9V form factor but about four times longer. I had a couple maybe 15 > years ago, I wonder if anyone makes those anymore. > > Directly rectifying the line is scary! > > The flyback with the Fairchild seems like a reasonable option.
http://svetelektro.com/Pictures/sil_casti/ZVS/schema.png -Lasse
On Mon, 22 Aug 2016 12:58:31 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

>Den mandag den 22. august 2016 kl. 21.53.56 UTC+2 skrev bitrex: >> On 08/22/2016 02:23 PM, John Larkin wrote: >> > On Mon, 22 Aug 2016 13:09:32 -0400, bitrex >> > <bitrex@de.lete.earthlink.net> wrote: >> > >> >> I need to throw together a ~150 volt supply at a few 10s of mA to test a >> >> circuit idea, but I don't have much in the way of MOSFETs in my junk box >> >> to build a switcher from. >> >> >> >> The only high-voltage device I have in stock is a couple Fairchild >> >> FQP2N60Cs, rated for 600V and 2 amps. That might be a possibility. >> >> >> >> I also have some lower voltage power devices, and I'm wondering if there >> >> would be a way to cascode two of them for a quick hack to make this work >> >> if I need to. Looks like I have some IRF530s, IRFZ24s, KSC1173 power >> >> BJT, the PNP equivalent KSA473, some MJE350s (high voltage but too low >> >> current) and whatever the NPN equivalent is. >> >> >> >> Anything I can do with this crap? >> > >> > How about a string of 9 volt batteries? >> > >> > Or rectify the AC line, with some prudent protections. >> > >> > You could make a flyback with the big Fairchilds. You could drive it >> > open-loop from a function generator. >> > >> > >> >> Stacking 9 volts would be fun, but it's an expensive way to run a thing >> if you plan on doing it for any length of time. I don't know if the >> internal resistance of the string would let me provide say 50 mA. >> >> They used to make big 45 volt alkaline batteries; they looked like the >> 9V form factor but about four times longer. I had a couple maybe 15 >> years ago, I wonder if anyone makes those anymore. >> >> Directly rectifying the line is scary! >> >> The flyback with the Fairchild seems like a reasonable option. > >http://svetelektro.com/Pictures/sil_casti/ZVS/schema.png > >-Lasse
That's not a flyback; it's a "fryback", a mosfet roaster. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On Mon, 22 Aug 2016 15:53:51 -0400 bitrex <bitrex@de.lete.earthlink.net>
wrote in Message id: <jLIuz.2$j44.0@fx24.iad>:

>They used to make big 45 volt alkaline batteries; they looked like the >9V form factor but about four times longer. I had a couple maybe 15 >years ago, I wonder if anyone makes those anymore.
Sure. Google be yer friend, eh? http://www.batteryjunction.com/exell-415a.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqMVOs3gSgtJ4H1T0agjdL8vqD5Y73JmOD6Kqp1PgeShoCOGDw_wcB http://www.batteryjunction.com/exell-455.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqVmk5JkCIFoPPvLaW2kCDma8e-HT2qEvbEV0s74amERoCrtfw_wcB
On Mon, 22 Aug 2016 16:21:33 -0400, JW <none@dev.null> wrote:

>On Mon, 22 Aug 2016 15:53:51 -0400 bitrex <bitrex@de.lete.earthlink.net> >wrote in Message id: <jLIuz.2$j44.0@fx24.iad>: > >>They used to make big 45 volt alkaline batteries; they looked like the >>9V form factor but about four times longer. I had a couple maybe 15 >>years ago, I wonder if anyone makes those anymore. > >Sure. Google be yer friend, eh? > >http://www.batteryjunction.com/exell-415a.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqMVOs3gSgtJ4H1T0agjdL8vqD5Y73JmOD6Kqp1PgeShoCOGDw_wcB > >http://www.batteryjunction.com/exell-455.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqVmk5JkCIFoPPvLaW2kCDma8e-HT2qEvbEV0s74amERoCrtfw_wcB
There used to be 90V "B" batteries for "portable" radios... I can still find mention on the web but none of the links seem to work. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I'm looking for work... see my website.
On Mon, 22 Aug 2016 13:29:45 -0700 Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in Message id:
<jtnmrb1k0o7ea51b0ionufhgoeqnd8cv3t@4ax.com>:

>On Mon, 22 Aug 2016 16:21:33 -0400, JW <none@dev.null> wrote: > >>On Mon, 22 Aug 2016 15:53:51 -0400 bitrex <bitrex@de.lete.earthlink.net> >>wrote in Message id: <jLIuz.2$j44.0@fx24.iad>: >> >>>They used to make big 45 volt alkaline batteries; they looked like the >>>9V form factor but about four times longer. I had a couple maybe 15 >>>years ago, I wonder if anyone makes those anymore. >> >>Sure. Google be yer friend, eh? >> >>http://www.batteryjunction.com/exell-415a.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqMVOs3gSgtJ4H1T0agjdL8vqD5Y73JmOD6Kqp1PgeShoCOGDw_wcB >> >>http://www.batteryjunction.com/exell-455.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqVmk5JkCIFoPPvLaW2kCDma8e-HT2qEvbEV0s74amERoCrtfw_wcB > >There used to be 90V "B" batteries for "portable" radios... I can >still find mention on the web but none of the links seem to work.
I remember those, for old tube radios. There doesn't seem to be any available anywhere. Here's some oddballs: http://www.batteryjunction.com/exell-493.html http://www.batteryjunction.com/exell-489a.html Wouldn't test those with my tongue!
On Mon, 22 Aug 2016 16:42:39 -0400, JW <none@dev.null> wrote:

>On Mon, 22 Aug 2016 13:29:45 -0700 Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in Message id: ><jtnmrb1k0o7ea51b0ionufhgoeqnd8cv3t@4ax.com>: > >>On Mon, 22 Aug 2016 16:21:33 -0400, JW <none@dev.null> wrote: >> >>>On Mon, 22 Aug 2016 15:53:51 -0400 bitrex <bitrex@de.lete.earthlink.net> >>>wrote in Message id: <jLIuz.2$j44.0@fx24.iad>: >>> >>>>They used to make big 45 volt alkaline batteries; they looked like the >>>>9V form factor but about four times longer. I had a couple maybe 15 >>>>years ago, I wonder if anyone makes those anymore. >>> >>>Sure. Google be yer friend, eh? >>> >>>http://www.batteryjunction.com/exell-415a.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqMVOs3gSgtJ4H1T0agjdL8vqD5Y73JmOD6Kqp1PgeShoCOGDw_wcB >>> >>>http://www.batteryjunction.com/exell-455.html?gclid=CjwKEAjwxeq9BRDDh4_MheOnvAESJABZ4VTqVmk5JkCIFoPPvLaW2kCDma8e-HT2qEvbEV0s74amERoCrtfw_wcB >> >>There used to be 90V "B" batteries for "portable" radios... I can >>still find mention on the web but none of the links seem to work. > >I remember those, for old tube radios. There doesn't seem to be any >available anywhere.
45V batteries are readily available. <https://www.amazon.com/Exell-Battery-455-45-Volt-Alkaline/dp/B00IDXP26S/ref=sr_1_1?s=electronics&ie=UTF8&qid=1471914583&sr=1-1&keywords=45v+battery>