Final Assembly

(The Beginning of The End)

This is it guys! The coil is practically done. Now that we have all of the components ready it was time to do the final assembly and place them all into the control cabinet, wire everything up, connect the two coil stands and perform some final tests. At this stage the coil is actually complete; however, the doesn't mean that the coil is finished, we still need to test and tweak it and fix any problems that arise.

We actually has a small mishap, the voltage and current screens that monitor the primary and aux circuits needed to have isolated power which we weren't informed about. This cause a short circuit of mains voltage crossing through the DC power circuit destroying the screens. New ones have since arrived and been installed, relays now isolate them. 

Once we officially finished the wiring in the control board, wiring and mounting began inside the control cabinet. The MOT stack power supply and voltage doubler were built and installed, the safety gap was correctly spaced and mounted and the charging choke assembly was fitted along with the primary MMC array. All of the latter components were then connected to the other components such as the spark gap and RF chokes with wire and solder. All necessary components were grounded and a new ground lead ran to our grounding rod. Also, a fresh coat of paint was added to the control cabinet.

We also had a problem with inrush current, the large variac was pulling tons of amps and caused our on board breaker to trip. We added a resistance circuit and short circuit switch to fix this.

As it was soon time to test the coil proper, we spent a good amount of time reviewing everything to ensure there was no potential problems that we had overlooked. Upon further inspection, the primary coil was dangerously close to the secondary. To prevent arc overs, we added acrylic tubing around the innermost coil. After doing so we decided it would be a good idea to apply the same principle to close cables inside the control cabinet. Wooden slabs were also inserted to help separate thing inside from crossing.

 We even decided to vacuum out all of the dust and wire cut offs to tidy thing up a bit.

Once the control cabinet wiring was done, we ran the HV cables from the cabinet out to the 2 coil forms and set it all up for preliminary testing.

The coil is done. After everything was set up, over the past few day we ran many tests. Many small problems came up such as bad soldering, broken contacts and power problems. All of these have been fixed now though. 

The aux circuit is officially done and works, the spark gap fans come on and the spark gap motor fires up and spins the disk. Using the tachometer and hall sensor, the disk reaches around 3200RPM before the tachometer cuts out. We were along using half the voltage from the variac at that point. A new tachometer is on order.

The final test ran today. This was the one of main power. We didn't expect it to work first time and our expectations were right. As previously insinuated by the very limited current carrying capacity and previous tests, the diodes lives were short lived and burnt out straight away. This prevented the voltage double from working and thus no arc across the spark gap. New diodes are on order, this time rated for 25kV at 2A.

Until they arrive there is nothing else we can do excluding small alterations and improvements.

The next blog post will be a test with them installed, hopefully then, the coil will have its first light.

Stay tuned, the end is right around the corner!

Next: First Light???

Horrible British Weather

We here in Britain have had intermittent downpours over the last few days that have hampered construction due to lack of indoor space.

That wont stop us though, time to set up the gazebo!

Next: Final Assembly

Huge Thank You

Project Exodus is nearly a year old and is so close to being complete. However, as you all know none of this would be possible without the kind donations and sponsors from people all around the world. To show are appreciation, here is a full list of everyone and every business that helped fund this project and made it possible for us to complete it.

Jozef Janitor

Mandy Greenaway

Claus Möhler

Randall J. Joslin

Tim Vass-de-Zomba

Karen Topham-Steele

Cliff Topham-Steele

Will Randall

Richard & Valerie

Randall Ray

Jon Quinton

Carolyn Davison

Simon Hill

Peter Reid

James Turnbull

Coleman Rasof

Chas Anders

Paul Leighton

Ian Rainford

Aircraft Value Analysis Company

Violetta Dudek

Phil Gillespie

Ralf Hülsmann

Magnus Svantesson 

LackLuster.org

Texas Micro Circuits

Next: Horrible British Weather

End of Summer Update

I'm back from holiday and so construction can finally resume. Now that the spark gap is done we now have all the pieces necessary to finish the coil which we hope to do in the coming week. Construction of the actual parts is officially finished excluding a few bits here and there so now it was time for assembly. This involves fitting all of the many components of the coil together in the control cabinet and board. Today we worked hard for many hours doing the above. (We also got some new lab coats =)

We started by finishing the wiring going from the control board to the big 15 amp variac. After sorting out a few problems in the control board we tested the variac and it works fine.

We fitted the quenching fans to the spark gap assembly and wired them. We then proceeded to connect the long conduit firmly into the control cabinet where it belongs. The control board is mostly finished now so we made a start on hot gluing all the contacts to prevent short circuits (defiantly needed as the screens blew up the first time). As that wiring was done it was time to start putting the larger items into the control cabinet and wiring them into place. We mounted the hall sensor on to the gap and mounted the whole thing into the cabinet. Wires were then ran from the spark gap motor, hall sensor and fans around the cabinet and were connected to the conduit. Long screws were cut down to size.

Now that the auxiliary circuit is finished we decided to test the whole thing. We shut the cabinet doors and tested the gap and fans at different voltages and thus speeds. Everything went well, the gap span at very high speeds without warping or hitting the electrodes and the tachometer displayed the speed. 

We did encounter one problem. It seems that the tachometer can only register a maximum RPM of around 3200. Were not sure if this is an equipment limitation, problem, or a result of using a different magnet with the hall sensor. The motor can go faster than this though. This is somewhat of a problem as are desired RPM to achieve a BPS of 500 is 3750 RPM. Because of this we will be buying a new tachometer and hall sensor which should arrive this or next week.

ATTENTION SPONSORS/DONATORS - As promised, your names and logos have been put onto the control cabinet. A picture of this will be posted in a few days. Also, your names and logos will be posted in the next post.

Next - Huge Thank You

New Spark Gap

After weeks and weeks of more work, the spark gap mark III is at long last complete. Are previous 2 died on us so here is the final installment. It is much more robust and can handle the max speed without warping. The disk was cut on a CNC laser cutter and the motor is secured to the base in a much stronger fashion now. We also opted to mount it downwards instead of the usual vertical orientation to help support it. Overall the whole assembly is designed way better than the earlier designs and so we are sure this one will be the final version. Here are some pictures:

I go away for a week next week so work will be postponed. After that however its full steam ahead to finish the coil. See you in a few weeks.

Next: End of Summer Update

Odds And Ends

The British baking summer has arrived so we decided to take the opportunity to work on the TC more in the boiling hot sun! Today mostly consisted of doing all the odds and ends jobs such as sanding down holes in the wood, cutting of the ends of exposed screws and sorting out the grounding wires. Here are a few shots. We also said goodbye to the old spark gap. It served us well but a new CNC cut out plastic disk will be arriving sometime next week. So tuned until then!

We even made some fans to keep cool using the old microwaves:

Next: New Spark Gap