Search found 109 matches

by Garrett Young
Mon Jun 26, 2017 1:42 am
Forum: Images du Jour
Topic: Neutrons!
Replies: 44
Views: 12435

Re: Neutrons!

NEW Personal Best!

Cathode Voltage: 52kV
Cathode Current: 12 mA
Pressure: 30 mTorr
Duration: 25 seconds
TIER (n/sec): 2,703,420 - electronic detection, 2,750,000 - dosimeter
Record-25June2017.png
Note: The RMS voltage and current isn't being calculated correctly (artificially low)
by Garrett Young
Sat Jun 17, 2017 4:32 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Christmas Comes Early!
Replies: 54
Views: 13671

Re: Christmas Comes Early!

Correction: Standard banana does work.

I'm now offering a high voltage cable (2.5 ft.) and all of the high power mods for $300 +shipping (including the price of the supply)
by Garrett Young
Sat Jun 17, 2017 2:01 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Switched Mode Power Supply
Replies: 50
Views: 11922

Re: Switched Mode Power Supply

Between a "stiff" centerpoint and current mode control they usually behave nicely ...
by Garrett Young
Sat Jun 17, 2017 6:36 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Switched Mode Power Supply
Replies: 50
Views: 11922

Re: Switched Mode Power Supply

You are correct, Rich.

I'm partial to the half bridge topology, since I think it's a good balance between cost, efficiency, and complexity.
by Garrett Young
Sat Jun 17, 2017 5:16 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Christmas Comes Early!
Replies: 54
Views: 13671

Re: Christmas Comes Early!

Turn off the lights and you may be able to see where the corona is happening.
by Garrett Young
Sat Jun 17, 2017 5:04 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Switched Mode Power Supply
Replies: 50
Views: 11922

Re: Switched Mode Power Supply

Rich, Is your primary turns based on a half or full bridge at 200V DC rail (and 0.2T in a 2cm^2 core)? 25 Turns is correct for a full bridge but not half. Likely the secondary would need more turns to account for leakage inductance (which is usually quite high for high voltage secondaries because of...
by Garrett Young
Sat Jun 17, 2017 4:41 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Christmas Comes Early!
Replies: 54
Views: 13671

Re: Christmas Comes Early!

I think a standard banana plug is too large to actually engage (at least it seemed to me). That may be why you are hearing some cracking. Silicone grease may help. What is the full scale current of your meter? If the meter is 10V FS and 1mA FS then it should work because the output impedance is 10ko...
by Garrett Young
Sat Jun 17, 2017 4:19 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Switched Mode Power Supply
Replies: 50
Views: 11922

Re: Switched Mode Power Supply

The front end driver is straight forward (half or full bridge) - see http://www.fusor.net/board/viewtopic.php?f=11&t=11146&start=146 I designed this produce 2.4kW of high frequency AC to drive a high voltage transformer/multiplier. The total part cost is about $100. The output multiplier is slightly...
by Garrett Young
Sat Jun 17, 2017 4:00 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Christmas Comes Early!
Replies: 54
Views: 13671

Re: Christmas Comes Early!

Did you pull pin 7 low? I've powered my fusor with this supply at 50kV/12mA. The HV cable is a non-standard length between the threaded connection and the internal high voltage terminal. In addition, the pin diameter needs to be smaller than the standard Spellman cable. I just mocked something up wi...
by Garrett Young
Sat Jun 17, 2017 1:44 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Christmas Comes Early!
Replies: 54
Views: 13671

Re: Christmas Comes Early!

I've now optimized the control loop components and the supply operates smoothly at 600W. I'm still operating at a low duty cycle, but it's very usable for fusion. If anyone is interested I could purchase supplies and modify and test them to 350 - 600W (depending on what you want) for $250 including ...