Thanks for the info, it great to see someone with some experience take a look at what i'm doing and give some advice. I have been debating exactly how to load the tube. Resistance, or actual tubes. I have a current limiting resistor on the output, so i will have to remove it and solder my zero impedance option pad so, i'm not limited. Do you have any suggestions/advise on the best method? Thanks again, you have been very helpful.
Jason On Apr 8, 7:58 pm, threeneurons <[email protected]> wrote: > | .. I am using the MK II design. a 4403 and a > | 4401 driving the fet. i am using a sdr1806-101kl 100uh inductor > | .. > > The 4403 & 4401 are a good choice. They were designed with switching > in mind. I use the (MMBT or MPS) A05 & A55, personally, but there > shouldn't be a measurable difference in this app. I also use the > SDR1806 in my latest design. Its a pretty beefy coil, and seems to > hold up well to abuse. The IPD60R380C6 FET is more than plenty for the > need at hand. After looking at its datasheet, I do notice that they > practice a bit of 'specmanship'. A little more than usual. Its a tad > better than a IRF740, but a lot less than the initial highlights > suggest. Otherwise, its still plenty good for the job. I'll be curious > to see your actualized efficiency, and max current. The RS1G is a > 'Fast rectifier' (150nS), as opposed to the 'ultra fast' (50/75nS) > types most of us, usually use. If your efficiency measures below 75%, > I'd substitute an ultrafast type in its spot, and see if that helps. > Your max output current (at 180V) should be ~30mA (+10mA/-5mA), given > a solid 12V input. Make sure your input supply can handle ~2 amps. A > sagging input supply will throw off your numbers. > > Going on a tangent, and back to simple bipolar transistors. The old > 2N2222, which most of us have used in mass, was originally designed > for switching service (Low saturation Vce at significant collector > current). With a fairly healthy current rating, that meant relay > driving. But somehow, it got to be used as a general purpose device, > used more often than not, in linear amplifier applications. If you can > find an old datasheet on the 2N2222, you'll notice 'Switching' in its > title. Most, if not all, modern datasheets list it as a 'general > purpose amplifier'. Moral of the story, is that sometimes you can get > away with using a device in some fashion other than originally > intended. As long as you stay within the 'Absolute Maximum Ratings' it > may actually do the job well enough for the app at hand. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
