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Are there no voltage boosters that can take 9V to 400V without a transformer? Seems like most of the build here is the power supply with a two component "counte

Are there no voltage boosters that can take 9V to 400V without a transformer? Seems like most of the build here is the power supply with a two component "counter" (which is really just a clicker since it does no counting). To me the much more interesting part would be where to get cheap geiger tubes. Edit: this has some answers on the power supply http://electronics.stackexchange.com/questions/70143/dc-dc-converter-12v-to-400v-is-this-possible http://electronics.stackexchange.com/questions/70143/dc-dc-c...

gaze 10y ago
You can do it with a simple boost converter. Additionally I don't think you really need a 555 or anything. There are self-resonant converters that should do the trick.
Animats 10y ago
Boost converters beyond 10:1 usually require a transformer. Efficiency of a transformerless boost converter goes down with the voltage gain, so there's a practical limit. It can be done without a transformer if you need very low current, but you need a big inductor. Here's a Geiger counter kit that does it.[1] It's rare to use a Geiger tube for this today, because PIN diodes can also detect radiation. But they need a low-noise high voltage power supply and a lot of low-noise amplification. Some circuits for that: [2] Geiger tubes have the nice property that the output signal is quite strong. I've been designing a boost converter that uses a 555 timer as the oscillator. It's part of a driver for my antique teletypes, which need 120VDC at 60mA briefly to pull in the selector magnet, then about 4V to sustain the magnet hold. Existing solutions are bulky and about 5% efficient. I've designed a version that is powered from a USB port. The design is on Github, in KiCAD format.[2] (Work in progress; haven't fabbed the board yet.) I'm using a 10:1 flat surface mount transformer from Coilcraft to get the size down. [1] http://www.rhelectronics.net/store/radiation-detector-geiger-counter-diy-kit-second-edition.html http://www.rhelectronics.net/store/radiation-detector-geiger... [2] https://www.maximintegrated.com/en/app-notes/index.mvp/id/2236 https://www.maximintegrated.com/en/app-notes/index.mvp/id/22... [3] https://github.com/John-Nagle/ttyloopdriver https://github.com/John-Nagle/ttyloopdriver

gaze 10y ago

You can do it with a simple boost converter. Additionally I don't think you really need a 555 or anything. There are self-resonant converters that should do the trick.

Animats 10y ago

Boost converters beyond 10:1 usually require a transformer. Efficiency of a transformerless boost converter goes down with the voltage gain, so there's a practical limit. It can be done without a transformer if you need very low current, but you need a big inductor. Here's a Geiger counter kit that does it.[1] It's rare to use a Geiger tube for this today, because PIN diodes can also detect radiation. But they need a low-noise high voltage power supply and a lot of low-noise amplification. Some circuits for that: [2] Geiger tubes have the nice property that the output signal is quite strong. I've been designing a boost converter that uses a 555 timer as the oscillator. It's part of a driver for my antique teletypes, which need 120VDC at 60mA briefly to pull in the selector magnet, then about 4V to sustain the magnet hold. Existing solutions are bulky and about 5% efficient. I've designed a version that is powered from a USB port. The design is on Github, in KiCAD format.[2] (Work in progress; haven't fabbed the board yet.) I'm using a 10:1 flat surface mount transformer from Coilcraft to get the size down. [1] http://www.rhelectronics.net/store/radiation-detector-geiger-counter-diy-kit-second-edition.html http://www.rhelectronics.net/store/radiation-detector-geiger... [2] https://www.maximintegrated.com/en/app-notes/index.mvp/id/2236 https://www.maximintegrated.com/en/app-notes/index.mvp/id/22... [3] https://github.com/John-Nagle/ttyloopdriver https://github.com/John-Nagle/ttyloopdriver