Minibrute Construction Thread / FAQs / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

Minibrute Construction Thread / FAQs

first previous 37 38 39 40 next last

Move Thread

LAN_403

audio:deviant

Sun Oct 04 2009, 08:43PM

Registered Member #2081 Joined: Wed Apr 15 2009, 11:36AM
Location:
Posts: 78

Sorry been a right fool found a short on the top of the board making it show the overcurrent! I still don't seem to be getting any pulse just 5 volts on the pin 2 of u4 and u5, I'm using 2 arduinos to produce the current feedback and ext mod but there about 3v output. Is this too low for it to be working? I thought there should at least be a weak signal

tritium

Sat Jan 02 2010, 01:12PM

Registered Member #2591 Joined: Fri Jan 01 2010, 11:58AM
Location: netherlands
Posts: 76

an question about the gdt,
I have a core FERROXCUBE - TN32/19/13-3E25 with has an Al of 6950nH

in the drawings I see that the primary is 250 uH, so when L=Al x n2 then I come to 6 turns for the primary on this core, am I right or do I have to order the core from the minibrute part-list?

HV Enthusiast

Sun Jan 10 2010, 12:53AM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

tritium wrote ...

an question about the gdt,
I have a core FERROXCUBE - TN32/19/13-3E25 with has an Al of 6950nH

in the drawings I see that the primary is 250 uH, so when L=Al x n2 then I come to 6 turns for the primary on this core, am I right or do I have to order the core from the minibrute part-list?

You want the cores on the parts lists, or ones that are very similar. Any deviation of these parts, and you are on your own for determing number of turns, etc...

UnionTesla

Tue Feb 23 2010, 03:45PM

Registered Member #2685 Joined: Sun Feb 14 2010, 07:23PM
Location:
Posts: 11

Hi, I have noticed that throughout this forum, people have been mentioning undeeded components that are listed in the miniBrute book, andI was wondering if there is a list of corrections that I should take into account when building one.

HV Enthusiast

Fri Feb 26 2010, 01:08PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

UnionTesla wrote ...

Hi, I have noticed that throughout this forum, people have been mentioning undeeded components that are listed in the miniBrute book, andI was wondering if there is a list of corrections that I should take into account when building one.

Hi. We are relaunching our company in April 2010 with a complete new product listing including COMPLETE kits for SSTCs and DRSSTCs. All the parts corrections which have been mentioned will be updated in this new website. Stay tuned . . .

AmonRa

Wed Mar 24 2010, 05:06AM

Registered Member #2704 Joined: Mon Mar 01 2010, 04:48AM
Location:
Posts: 6

I successfully completed this coil last week. Great design EVR and a well put together book. Thanks to your input in this thread and all of the great info from the other builders, I assembled the coil, completed the testing, turned it on, and had streamers on the first try. A week later, after tuning, it is still going strong without ever having blown up a single component (knock on wood).

I did find one thing in the schematics that has been mentioned here but was not answered. The initial setting for the overcurrent setpoint has you set the voltage at u21-2 to 2.59v via r23. After first light, per the instructions in the book, I went back to r23 to adjust the setpoint up to 500A. I found that I was only able to get 5vdc max at u21-2 with the 10K pot r23 turned down to near 0 resistance.

After checking the input voltage to r23, I found that there was only 5vdc going into the pot. The schematic shows 15v as the input. Taking a look at the pcb, I followed the trace from the r23 input to where it connects to the top of r85. The schematic figure 2-4 shows that the input to r85 is 5vdc which is correct in the book and on the pcb. The schematic figure 2-2 shows that the input to r23 is 15vdc, which is incorrect in the book. It's only getting the 5vdc from top of r85.

I have absolutely no intention of running my coil above 500A, so really, no change needs to be made. However, I though it was still worth pointing out in this thread.
Also, as stated several times in the thread and in the book, running above 500A drastically reduces system reliability; doing so is at your own risk.

If a builder does wish to be able to adjust the overcurrent setpoint throughout the entire range up to 1000A, cut the pcb trace between pot r23 and r25 and run a trace wire on the back of the pcb from u21-8 to the input side of pot r23. Now you will be able to set the voltage at u21-2 from 0 - 15vdc allowing you to run over 500A current limiting.

Once again, great design EVR. This coil is a whole lot of fun.

UnionTesla

Wed Apr 14 2010, 09:29PM

Registered Member #2685 Joined: Sun Feb 14 2010, 07:23PM
Location:
Posts: 11

So, I am currently in the process of making the minibrute, and I am wondering how people who have successfully built it bent the strike rail. Did you have to anneal the copper?

AmonRa

Wed Apr 14 2010, 11:42PM

Registered Member #2704 Joined: Mon Mar 01 2010, 04:48AM
Location:
Posts: 6

I bent the copper strike rail around a pot i had in the kitchen thanks to the nice tip found earlier in this thread. It wasnt exactly the same diameter, but close enough and the rail expanded a bit naturally when pressure was released. Find a pot or 5 gallon bucket or something similar in diameter and slowly bend the rail around while holding one end in place.

HV Enthusiast

Thu Apr 29 2010, 05:11PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

Beautiful coil AmonRa! Excellent craftsmanship and a very nice output arc!

Austin

Fri Apr 30 2010, 08:05AM

Registered Member #1169 Joined: Wed Dec 12 2007, 09:16AM
Location: Portland OR
Posts: 251

EastVoltResearch wrote ...

Beautiful coil AmonRa! Excellent craftsmanship and a very nice output arc!

indeed

first previous 37 38 39 40 next last

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob