/sci/ - Science & Math

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Anonymous Sat Oct 23 23:22:45 2010 No.1941808 [Reply] [Original]

Any electrical engineers? Or physicists (you regularly make circuits online?

Building a TColi and I got a few questions

>>	Anonymous Sat Oct 23 23:25:45 2010 No.1941822 File: 1.03 MB, 2100x1766, e_coli.jpg [View same] [iqdb] [saucenao] [google] E. Coli, you say?

>>	Anonymous Sat Oct 23 23:26:45 2010 No.1941828 TESLA COLI'S WE ARE DOOMED!!!

>>	Anonymous Sat Oct 23 23:29:45 2010 No.1941843 Moar?

>>	OP Sat Oct 23 23:29:45 2010 No.1941848 File: 73 KB, 673x806, 111.jpg [View same] [iqdb] [saucenao] [google] So I am supposed to measure these waves on the IGBTS, I know to connect the red (leads) to the the Gates, where do I connect the black (ground)? To the Collecctor? Emitter? Somewhere else?

>>	Anonymous Sat Oct 23 23:30:45 2010 No.1941856 >>1941828TESLA COLI Pack it up people, we're fucked

>>	Anonymous Sat Oct 23 23:30:45 2010 No.1941857 bitches dont know bout my LC circuits

>>	OP Sat Oct 23 23:31:45 2010 No.1941863 >>1941848 To the Power Ground?

>>	Anonymous Sat Oct 23 23:33:45 2010 No.1941875 Sauce on OP's pic plox.

>>	Anonymous Sat Oct 23 23:34:45 2010 No.1941879 >>1941863 Yes. What sort of 'scope you have?

>>	OP Sat Oct 23 23:42:45 2010 No.1941922 File: 31 KB, 567x421, 222.jpg [View same] [iqdb] [saucenao] [google] >>1941879 Tektronix T922R, just a regular ossilloscope (kinda old). In the diagram I cant figure out what parts are what for the IGBTS? which side is the Gate? The collector? The Emmiter?

>>	Anonymous Sat Oct 23 23:48:45 2010 No.1941939 >>1941922 The gates are on the left. I've never worked with IGBTs before, but I'm reasonably certain that the collector is above the emitter.

OP Sat Oct 23 23:55:45 2010 No.1941962
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>>1941939
Ok thanks, So does it make sense that one of the emiiters would be then collected to Power ground? Also, to then view the waves forms >>1941848, since The emiiter is at Power ground, would I just connect both of the grounds (from the ossillocaope) to the emmiter of the bottom IGBT?

>>	OP Sun Oct 24 00:02:45 2010 No.1941982 File: 115 KB, 850x594, 1270850565170.jpg [View same] [iqdb] [saucenao] [google] bump

Anonymous Sun Oct 24 00:04:45 2010 No.1941993

>>1941962
I've never built a Tesla coil before but I think the circuit makes sense. Connect your scope grounds to the power ground. The gate voltage for the lower IGBT should be easy to see. The signal at the upper IGBT might be really high though, does your scope handle > 400V?

OP Sun Oct 24 00:11:45 2010 No.1942029
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>>1941993
Ok, Thanks, I am not actually running at 400V yet, I am still In test mode, running with very Low voltages (12VDC and 5VAC), just to make sure all the waveforms are right.

Anonymous Sun Oct 24 05:13:45 2010 No.1943042

Normally there's no need to measure the upper base voltage directly because it shows up as the negative part of the voltage on the lower IGBT. That's because you have a 1:1 transformer in the drive chain. Don't expect a perfect square shape though, there's always some ringing.

>>	Anonymous Sun Oct 24 05:19:45 2010 No.1943057 more of chick op

Anonymous Sun Oct 24 05:27:45 2010 No.1943073
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>>1943042
Yeah, and the pic in >>1941848, indicates this is what we should see. The probelm I was having/still having is I must have construced the GDT incorrectly, as I was getting nothing on my ossilloscope. I am redoing it right now, hopefully, I get the proper waveforms.

OP Sun Oct 24 05:37:45 2010 No.1943094
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OOPS!

Another question: I am supposed to input at 500Khz Square Wave in place of the current transformer. Does that mean I connect the black wire the the black circle and the red wire to the red circle (I drew in the circles myself)???

>>	OP Sun Oct 24 05:39:45 2010 No.1943096 File: 126 KB, 800x667, 1271192392474.jpg [View same] [iqdb] [saucenao] [google] >>1943094 >wires of my function generator that is

>>	Anonymous Sun Oct 24 05:39:45 2010 No.1943098 Physicsfag here. I built a calculator with no experience in electrical engineering nor logic gates. That's about it though.

>>	Anonymous Sun Oct 24 05:45:45 2010 No.1943106 >>1943094 ...Is that a bomb diagram? Are you defusing a bomb? Are you asking /sci/ for help defusing a bomb?

>>	Anonymous Sun Oct 24 05:58:45 2010 No.1943124 File: 80 KB, 800x600, 1271791882890.jpg [View same] [iqdb] [saucenao] [google] >>1943106 LMAO, no, its a Tesla coil. The whole schematic is huge. I had a few questions about it, and posted the relavents parts of the schematic.

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