Re: Cap surge current
Here is a sch of caps and they are actually parallel my bad [url]https://www.badcaps.net/forum/attachment.php?attachmentid=60863&d=1364173402[/url]Re: Cap surge current<br />
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...64173402[/url]
JohnnyRC
Member
Last Activity: 04-13-2013, 10:44 AM
Joined: 03-24-2013
Location: Chandler AZ
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Re: Cap surge current
Let me clarify that the caps are placed in a switch mode power supply type applicationLeave a comment:
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Re: Relay?
You mean a snubber cap? I've also seen MOV's to help drain inductive spikes. I don't think I've ever seen caps tho......Leave a comment:
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Cap surge current
Heres a good one, anyone know what surge (in amps) can be expected on a very low impedance low reactance load using 10000 uf 450 volt caps seriesed versus 6000 uf 450 volt caps seriesed with supply voltage of 300 vdc? The caps have fairly low ESR and low ESL but I have no way of checking -
Re: Blown Bridge Rectifiers yes plural
Thanks I just changed the TVSS's and seems to be running fine. Thanks for the advice.
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Re: Blown Bridge Rectifiers yes plural
jeez guys can anyone please explain ripple current? is it inductive spikes?Leave a comment:
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Re: Blown Bridge Rectifiers yes plural
i checked for shorted TVSS is there another way to check these?...Leave a comment:
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Re: Blown Bridge Rectifiers yes plural
[QUOTE=kaboom;325227]
i will replace the TVSS's as i'm not really sure if they are blocking or not. ohm meter reads open but... with high voltage could be shorting the bus.. plus getting 100 of them. earlier you mentioned ripple currents across the bus caps do can you explain please as i'm a meager noobRe: Blown Bridge Rectifiers yes plural
[QUOTE=kaboom;325227]
i will replace the TVSS's as i'm not really sure if they are blocking or not. ohm meter reads open but... with high voltage could be shorting...Leave a comment:
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Re: Blown Bridge Rectifiers yes plural
[QUOTE]Semis usually short, so use the continuity check on your meter. If one or more is shorted, the IGBTs, when switching on, will short the DC bus.
Checked the semis they are all ok. It figures cause I just bought 100 of them....Anyone need some bi directional diodes they are line voltage!
I plan on making a few more of these with similar config so no bigRe: Blown Bridge Rectifiers yes plural
[QUOTE]Semis usually short, so use the continuity check on your meter. If one or more is shorted, the IGBTs,Leave a comment:
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Re: Blown Bridge Rectifiers yes plural
[QUOTE]No. They direct current back into the caps, raising the bus voltage. Energy is commutated from the coil back to the bus. The impulse across the caps will be low, provided the ESR is low. You should have heavy litz wire or buss bar from the caps to IGBTs. Also, put a low ESR/ESL film cap, such as this:
[url]http://www.ebay.ca/itm/TPC-CAPACITOR...item19da2ee715[/url]
across the rails feeding the IGBTs, as physically close as you can. This will keep the high frequency ripple away from your electros, keeping...Leave a comment:
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Re: Blown Bridge Rectifiers yes plural
ok i just realized that the diodes are bi-directional......had no idea diodes could do that but here are some specifics and is there a way to check bi-directional diodes? prferably without de-soldering.
P6KE220CA 600W BIDIRECTIONAL TRANSIENT VOLTAGE SUPPRESSION DIODE
Max Continuous Voltage 185V
Minimum Breakdown Voltage 209V
Maximum Breakdown Voltage 231VLeave a comment:
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Re: Blown Bridge Rectifiers yes plural
guys, here is bridge sch. there is one cornell dubiler snubber capacitor .15 mfd 2000vdc in parallel with the diode array between collector and emitter on each IGBT that the sch doesnt show. thank you and i am a mere knowledge seeker and am having fun with high voltage!!
[ATTACH]60864[/ATTACH]...Last edited by JohnnyRC; 03-24-2013, 07:15 PM.Leave a comment:
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Re: Blown Bridge Rectifiers yes plural
here is the doubler circuit. i am using a variac for input for isolation i will post the bridge sch later tonight for reference. thank you
[url]http://www.coolcircuit.com/circuit/voltage/vd.GIF[/url]Re: Blown Bridge Rectifiers yes plur...e/vd.GIF[/url]Leave a comment:
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Blown Bridge Rectifiers yes plural
Hello, I have a doubler circuit that keeps shorting my KBPC50-600v 50amp bridge rectifiers, two to date. I am using the doubler on an H configuration IGBT bridge. My caps are RIFA 400v 6000 uf big ones. They are within range. I have no way to check ESR unless someone knows how to check using one of these: [url]http://www.ebay.com/itm/LC100A-High-precision-Inductance-Capacitance-L-C-meter-/250853871796[/url]
There are snubbers in place to prevent kickback and my question is: wouldnt kickback kill the rectifier? Or high ESR on caps or single cap cause this?. I am running a double resonant...
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