A 5V to 500V converter for Geiger Muller Tube

[ChangBroot]

I want to build a radiation detector using GM Tube (SBM-20). The GM Tube requires 400 volts DC and I am using arduino board for data collections and manipulation as well as PWM. Arduino uses 5/9V DC. My DC-DC Converter is a simple boost converter like this. I have found several schematics for a boost convert using timer, but since I use Arduino, I don't need a timer.

I was able to convert the 5V DC to 80V DC using transistor 2N3904 and Diode 1N4005 that I had at hand. The 800kOhm resistor gave a few micro amps that I wasn't even able to measure with my muleteer.

My problem is that I can't find the name of the components so I could buy them. So, I need either a schematic with components OR list of Transistors and Diode that i could use with my schematic (No large components).

Any help is greatly appreciated. Thanks.

 

[dick_freebird]

Are you averse to buying a ready-to-go high voltage
DC-DC module? These can be fairly inexpensive and
nicely potted. EMCO, for example, has a nice line of
tiny ones (and their web pages will give you plenty
of searchable keywords, if they fail to satisfy).

 

[ydtech]

Have a look at the kind of circuit used in electronic flash units. You can rip one out of an old unit, but they usually generate 300 - 400 volts, so you may end up winding your own.

 

[Warpspeed]

I did something similar myself with an SBM-20 soon after Fukushima.

If its to be mains powered, then one of those EMCO high voltage modules that Dick suggested would be ideal.
If its to be battery powered, the 12v at 100mA required quickly becomes rather a burden.

The SBM-20 has no real measurable operating current, its absolutely tiny.
So an extremely low power boost converter might be the answer, but it will require more work and complication to build.
I spent about a week developing my own +400v boost converter, and it draws about 900uA from a PP9 battery which lasts for about ten days.

After all that, these days, I run it continuously in the kitchen off a 9v wall pack, so in retrospect an EMCO module would have been a much simpler solution.

Gamma background in Melbourne Australia ranges from about 60 to 95 microsieverts per hour, and its up and down like yo-yo from hour to hour.

 

[chuckey]

Look at Cockcroft-Walton voltage multipliers. You will need 10 diodes and 10 capacitors. Or put more turns on your transformer to get more volts out of it.
Frank

 

[tanveerriaz]

hare Is a project use fet and diode for high voltage.
**broken link removed**
http://smartelectronix.biz/publ/prostoj_detektor_radiacii_na_schetchike_gejgera_sbm_20_on_zhe_sts_5/1-1-0-10

 

[ChangBroot]

Thanks a lot everyone. I appreciate your help.

@dick_freebird and @Warpspeed, are you guys talking about emcohighvoltage? All their products require input voltage of more than 100V. That being said, I am willing buy a $10 or less converter because I want to build the least amount (but not a knock off one).

 

[BradtheRad]

Online I found schematics for my old Victoreen 700 geiger counter. It's ca. 1960, so it's made from discrete parts, few parts, repairable, etc.

Its flyback converter converts a few volts to several hundred V.

Schematic:

 

[Warpspeed]

@dick_freebird and @Warpspeed, are you guys talking about emcohighvoltage? All their products require input voltage of more than 100V.

These are the ones from EMCO.
Choice of 5v (or 12v) input, 0 to 500v adjustable output
**broken link removed**