paulf@solist.htsa.aha.nl (Paul Ferron) (12/20/89)
I'm looking for a design to convert a 9V DC to 1800V. It is for a Neontube of about 500 mm long. The design has to be with an oscilator. thanks in advance. ******************************************************************* * RETURN MAIL TO : So much to learn, * * paulf@solist.htsa.aha.nl so little time...* *******************************************************************
richm@amc-gw.amc.com (Rich Moran) (12/21/89)
In article <1269@maestro.htsa.aha.nl> paulf@solist.htsa.aha.nl (Paul Ferron) writes: }I'm looking for a design to convert a 9V DC to 1800V. } }It is for a Neontube of about 500 mm long. } }The design has to be with an oscilator. } }thanks in advance. } How much current does it need to supply at 1800VDC? How much peak and average current can your 9VDC source? -- ============================================= Rich Moran richm@amc.com =============================================
mac@harris.cis.ksu.edu (Myron A. Calhoun) (12/21/89)
In article <1269@maestro.htsa.aha.nl> paulf@solist.htsa.aha.nl (Paul Ferron) writes: >I'm looking for a design to convert a 9V DC to 1800V. >It is for a Neontube of about 500 mm long. >The design has to be with an oscilator. >thanks in advance. I hope you aren't trying to start with a 9-volt "transistor" battery! I don't know how much current a Ne tube will need, but let's assume one milliampere (that's about what I put through an Ne-2 pilot lamp); let's also assume a 50 percent efficiency in the conversion: 0.001 amp x 1800 volts = 1.8 watts. 1.8 watts x 2 = 3.6 watts when allowing for conversion inefficiency. 3.6 watts / 9 volts = 0.4 amps = 400 milliamperes, which is about 10 times the maximum practical current drain on a little "transistor" battery. Of course, several of my assumptions may be wrong. -- --Myron. #---------------------------------------------------------------------- # Myron A. Calhoun, Ph.D. E.E.; Associate Professor # Department of Computing & Information Sciences (913) 539-4448 home
pophal@nicmad.UUCP (Gerry Pophal) (12/23/89)
The March 1989 issue of Radio-Electronics has an article on page 33 titled
Build this universal laser power supply. It boosts 12v up to 1200-3000 volts.
Also there are dc laser supplies available commercialy/surplus.
gpjgk@osc.COM (Joe Keane) (12/23/89)
In article <1269@maestro.htsa.aha.nl> paulf@solist.htsa.aha.nl (Paul Ferron) writes: >I'm looking for a design to convert a 9V DC to 1800V. >It is for a Neontube of about 500 mm long. >The design has to be with an oscilator. > >thanks in advance. In article <1989Dec20.184339.21760@deimos.cis.ksu.edu> mac@harris.cis.ksu.edu (Myron A. Calhoun) writes: >I hope you aren't trying to start with a 9-volt "transistor" battery! > >I don't know how much current a Ne tube will need, but let's assume >one milliampere (that's about what I put through an Ne-2 pilot lamp); >let's also assume a 50 percent efficiency in the conversion: > >0.001 amp x 1800 volts = 1.8 watts. >1.8 watts x 2 = 3.6 watts when allowing for conversion inefficiency. >3.6 watts / 9 volts = 0.4 amps = 400 milliamperes, > >which is about 10 times the maximum practical current drain on a >little "transistor" battery. Of course, several of my assumptions >may be wrong. Hmm, what is a good drain on a transistor battery? All i know is that i have run small HeNe tubes from them and a wimpy switching power supply. The power output of batteries can be impressive, especially for short surges. The short-circuit current of a good D cell is something like 20 amperes, and a car battery can put out up to 500 amperes to cold-crank the starter motor. Anyway, back to the original question. There are a bunch of ways to do it, but they all come down to rapidly changing the current in a coil to induce a voltage, in that coil or a different one. Here's a circuit description off the top of my head. Run a 555 from the battery to make a 20KHz or so signal, which gates some power FETs. These switch a capacitor forwards and backwards into the primary of a step-up transformer, which has diodes clamping it to prevent having hundreds of volts across the FETs. This capacitor is recharged from the battery through a small resistance, the idea being to supply current spikes from the capacitor rather than the battery. On the transformer secondary you may have a couple stages of a voltage multiplier ladder, then a final capacitor to dump into. That's the general idea. To make it specific you need to know the output current needed and the allowable drain on the battery. You have to find an available transformer, and get its turns ratio and magnetizing inductance. Then you can figure out what the FETs have to be rated for, what sort of ladder (if any) you want, and a whole slew of appropriate capacitor values.
mac@harris.cis.ksu.edu (Myron A. Calhoun) (12/24/89)
In article <1765@osc.COM> jgk@osc.COM (Joe Keane) writes: >In article <1269@maestro.htsa.aha.nl> paulf@solist.htsa.aha.nl (Paul Ferron) writes: >>I'm looking for a design to convert a 9V DC to 1800V. [many lines deleted] >Hmm, what is a good drain on a transistor battery? All i know is that i have >run small HeNe tubes from them and a wimpy switching power supply. From an Eveready Battery Applications & Engineering Data book: (ca. 1965!) Ever. ASA Sug. Hours Start Serv. Hours Start Serv. Hours Start Serv. Numbr Type Mamps perday Curr. Hours perday Curr. Hours perday Curr. Hours -------------------------------------------------------------------------------- 915 AA 0-25 2 10 92 8 10 64 24 1 1040 30 20 30 10 2 420 5 130 935 C 0-80 2 10 190 4 10 210 24 2.5 1000 50 33 50 25 5 440 100 13 100 7 10 170 950 D 0-150 2 10 450 4 10 530 24 10 500 100 35 100 30 20 165 200 11.5 200 9 30 88 216 9Volt 0-8 2 12 34 4 9 46 "xstr" 16 24 Ni-Cd 0-1500 150 10.5 300 4.5 450 3 My complete table (copied laboriously from the original--no photocopy available then) also includes weights, volumes, cutoff voltages, and some other stuff. Please note that the above data was from ONE manufacturer and is very OLD. Surely cells have been much improved since then. It would be interesting to ask Eveready for an updated chart--if anyone does, please post. --Myron. -- #---------------------------------------------------------------------- # Myron A. Calhoun, Ph.D. E.E.; Associate Professor # Department of Computing & Information Sciences (913) 539-4448 home # Kansas State University, Manhattan KS 66506 532-6350 work