Minibrute Construction Thread / FAQs / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

Minibrute Construction Thread / FAQs

first previous 6 7 8 9 next last

Move Thread

LAN_403

Austin

Fri Jan 25 2008, 03:41AM

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

Wire, what resistor did you use for R29? Its listed twice in the parts list with two different resistors. Also R28 says "open" on the schematic but I don't have a part for it.

How did you mount the heat sinks to the board (did you use solder for adhesion) for U61, U62 etc...?

Thanks Wire, I could not do this without your help.

HV Enthusiast

Fri Jan 25 2008, 04:11AM

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

Austin wrote ...

Wire, what resistor did you use for R29? Its listed twice in the parts list with two different resistors. Also R28 says "open" on the schematic but I don't have a part for it.

How did you mount the heat sinks to the board (did you use solder for adhesion) for U61, U62 etc...?

Thanks Wire, I could not do this without your help.

R28 should be open. All this sets is the gain on the op-amp. With it open, the op-amp acts simply as a buffer (gain=1)

Heat sinks (which probably aren't even required - i don't think U61 and U62 get hot) bolt to the board with a screw / nut through the TO-220 mounting hole.
They aren't soldered to the board.

Austin

Fri Jan 25 2008, 04:14AM

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

I'm not sure bolts came with those parts hrm maybe ill find some around the house.

what about R29?

Wirenut

Fri Jan 25 2008, 05:24AM

Registered Member #141 Joined: Sat Feb 11 2006, 01:14PM
Location: Southern California
Posts: 96

what about R29?

I used the 10k.

Austin

Fri Jan 25 2008, 06:18PM

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

Are three wires being wrapped around T1?
Ie, Wire#1 is (S1/S2), Wire #2 is (G1/G2), Wire #3 is (twisted pair -> Gate DRV/RTN -> from the resonant board)?

Not quite. There are 3 wires, but wire 1 will be s1/g1 and wire 2 will be s2/g2. Wire 3 is correct. I had a hard time finding wire that was small enough to fit 20 turns on the ferrite. What I ended up using was wire from an old parallel cable. I took 2 strands (red and blue in my pic) and twisted them tightly together using a drill. I then wrapped 20 turns on the ferrite. Then I wrapped 10 turns over the top of the red and blue (yellow in my pic) with a third wire. I fed the leads of the 3rd wire through the holes in the board and then twisted them together, holding the ferrite to the board. I could then trim the red/blue wires to the correct length. I'm not sure if it matters, but I put both turn-1-wires to g and both turn-20-wires to s.
[/quote1201284778]

I have never done this before, so i want to twist together my s-wire and g-wire together before wrapping it around the the ferrite and then wrap the gate drv wire around the ferrite 10 times over the s,g wire... ill read up on this some more, i just finished my boards except for this ferrite business and then i'm on to building the primary. =P

Wirenut

Fri Jan 25 2008, 08:03PM

Registered Member #141 Joined: Sat Feb 11 2006, 01:14PM
Location: Southern California
Posts: 96

Here's a close-up pic of my GDT

The red and blue wires are twisted together. There are 20 turns of the red/blue around the core. You can see the red wire is connected to s2 and g2 on the left side of the board. The blue wire is connected to s1 and g1 on the right, but is not visible.

Austin

Sat Jan 26 2008, 06:28AM

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

Wire I see what you mean when you say its hard to get 20 turns in, i'm using 18gauge wire to wrap around the ferrite I think I need something even smaller.

Wirenut

Sat Jan 26 2008, 07:09AM

Registered Member #141 Joined: Sat Feb 11 2006, 01:14PM
Location: Southern California
Posts: 96

I need something even smaller.

Do you have an old computer parallel cable laying around? This is what I used. I couldn't even make the 24ga. wire from a cat-5 ethernet cable fit.

Austin

Sat Jan 26 2008, 07:34AM

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

I think I might, I just hope its long enough. did you use the same gauge wire for all 3 wire?

Wirenut

Sat Jan 26 2008, 08:03AM

Registered Member #141 Joined: Sat Feb 11 2006, 01:14PM
Location: Southern California
Posts: 96

I think I might, I just hope its long enough. did you use the same gauge wire for all 3 wire?

Yes, all three were from the parallel cable. I think it was about 5' long. I think they're about 26ga. - just barely smaller than 24ga. cat-5 wire.

first previous 6 7 8 9 next last

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