> Jeepers, Buddy! 475V at 50mA? Did you check your life insurance? > > Not popular for supplies in the few-watts range, but if you need this > sort of power maybe a valve amp transformer is going to be your better > bet?
I regularely use transformers from Tektronix oscilloscopes and valve amplifiers for my projects, and I am really really careful when testing stuff. Valve amp transformers are so large and heavy since they usually contain one or more heater windings which use up perhaps 50% of the weight and size. I've actually been thinking about using two small transformers back to back for supplying the 475V I need for each module in the design. A Tek transfomer can supply approximately 100mA at 500V (50VA) but up to 50A for the 6.3V (315VA) windings - which I don't need in this project as I am going 100% cold cathode tubes except for the diodes/rectifiers - cold cathode diodes/rectifiers are not suitable here due to their high working voltage, unless anyone know of any low voltage types. I've been thinking about using neon lamps but they too have a too high voltage drop. This way there will be a lot of transformers and the weight will almost be as much as from a large transformer, but atleast it will be possible to distribute the weight better. I know of a guy who can wind transformers as a last resort so I can partly get rid of the size/weight problem but that will eat a large hole in my economy. So far I have only been bitten by a damaged valve tester when it had a short from a broken relay coil to the case, this relay only shorted when the relay was actuated which it normally shouldn't be as it works as an over current protection - but of course I tripped the over current protection and got bitten a few times. This if you excempt all shocks I got when I was new to electronics and put my fingers in TV sets that were turned on, but that was a long time ago and I only have a few burn scars to show from that period. ;) I recently bought a pair of rubber gloves specially made for high voltage use, they can withstand 5KV and comes with a pair of inner gloves made out of cotton so you shouldn't sweat while wearing them. I'll use these now as I have three kids to think of nowadays! Whoops, got a little bit carried away there - but that is the fun with this hobby! -- 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.
