Help building a boost converter

Hey guys,

I'm trying to build a boost converter to charge up the capacitors for a school project, but I don't seem to have very much success. I'm trying to boost 12v up to 750V, which requires a duty of 98.5% if my calculations are right. With the use of some online calculators (namely: http://www.daycounter.com/Calculators/Switching-Converter-Calculator.phtml and) I got an inductor value of 42mH, and have a 100mH inductor plugged into my boost converter to test. The capacitors I have plugged into the output are two 100uF caps rated at 450V in series. (The final capacitors I need to charge are 4050uF rated at 800V) But when I measure the output, I get only 0.655V.

I can't seem to figure out why I am not getting any useful values, can any of you help?

Thanks

Sorry, couldn't find the edit button, but i was basing my schematic around this person's:
http://www.anothercoilgunsite.com/img-schematic-boost-a1.gif

Hello,

the problem is, that your boost converter has not enough power to charge the capacitor.
An emty capacitor is like a short circuit for your supply.

It's better to use a converter with a transformer so you have more Power to charge the capacitor.
I'll look for a circuit, that was used in a Photoflashlight. I must draw this diagram, because I have built it 40 years ago.
After finishing the drawing I'll post it.

Regards

Rainer

PS: Sorry if my English is too bad.

Hello,

I am closing this thread as it violates AAC policy and/or safety issues.

Quote:
6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:
Any kind of over-unity devices and systems
Automotive modifications
Devices designed to electrocute or shock another person
LEDs to mains
Phone jammers
Rail guns and high-energy projectile devices
Transformer-less power supplies
This comes from our Tos:
Terms of Service

Bertus