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### Topic: Voltage Boosting Circuitry (Read 1 time)previous topic - next topic

#### Swim100flyy

##### Jun 16, 2011, 07:03 pm
Question.

I am looking to charge a larger capacitor to a 'high voltage' somewhere in the realm between 50-400 volts.

Yes, I know capacitors are dangerous in regards to electric shock, explosion, line faults, etc... I have and continue to use safety protection and protocol when working around this equipment, so please don't bash me before for inexperience before hearing me out.

My supply voltage is DC 1.5-15 volts (output to capacitor is between 50-400 volts).

From my research it looks like a DC-DC boost circuit is the most approachable method.

The simplest circuit I have found is this one:
http://www.arduino.cc/playground/Main/RegulatedPositiveVoltageBooster

What are your thoughts? Is there a better method?

Thanks,
Swim.

#### RuggedCircuits

#1
##### Jun 16, 2011, 07:36 pm
In theory this will work. 50V should be doable, but once you start getting into the 400V range you have to carefully consider the voltage ratings of your components. For example, your switch transistor has to withstand 400V, and definitely a little bit more for headroom. Same with your diode, inductor coils, etc. Theory goes a little bit out the window as the voltages climb (or, more accurately, you have to be very aware of component ratings and parasitic properties, like the capacitance of your inductor).

Also research the "flyback converter" topology, as that might be a bit safer for your Arduino and you will get a natural voltage boost from the transformer.

--
The Ruggeduino: compatible with Arduino UNO, 24V operation, all I/O's fused and protected

#### Grumpy_Mike

#2
##### Jun 16, 2011, 08:41 pm
I wouldn't use that sort of circuit, it's not isolated. Instead I would get a 6v mains (240v) transformer and drive the secondary with 12v switched from a H-bridge. Then out of the mains side would come 480v RMS, which will give you what you need when you have rectified it.
Look at circuits to drive GM tubes.

#### jackrae

#3
##### Jun 16, 2011, 08:42 pm
Get hold of a "disposable, single use" cheapo camera with inbuilt flash and take it apart to recover the inverter unit.  This will generate around your 400 volts from a AA battery.   If you talk nicely to your local photoshop they may have a stock of these in their rubbish bin.

#### mmcp42

#4
##### Jun 16, 2011, 09:20 pm
another good source is a scanner
the light is a sort of flourescent tube that runs at quite a high voltage
there are only 10 types of people
them that understands binary
and them that doesn't

#5
##### Jun 16, 2011, 09:25 pm
Look up things  like Nixie tube wrist watch, uses disposable camera for the high voltage as jackrae said.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

#### Swim100flyy

#6
##### Jun 16, 2011, 09:33 pmLast Edit: Jun 16, 2011, 09:46 pm by Swim100flyy Reason: 1
Yes, I have been using a camera flash charger for the time being...however:

I want to increase Vin from 1.5 up to 12 volts
I want to be able to go down to 50 volts....the charger is set around 300.

For noise isolation - couldn't I use an opto-coupler on the transistor signaling?