High Voltage Forum

Tesla coils => Vacuum Tube Tesla Coils (VTTC) => Topic started by: kaboooom2000uk on April 30, 2021, 09:34:11 AM

Title: My first VTTM (Vaccum tube tesla magnifier) WIP
Post by: kaboooom2000uk on April 30, 2021, 09:34:11 AM
Hello Ladies and Gentlemen, I present my VTTM which I believe may be a first as I haven't seen any circulating the internet, seen plenty of classic spark gap derived machines, but none where they employ a tube oscillator. Mine uses a little 830B tube which seems to perform well and provides about 6" arcs.

here I use a simple schematic from an induction heater but I have modified the work coil to work at the same Fres as my secondary (which I established using the signal generator and scope method as I find it simpler to do this) and built it using parts around the shack. As you can see the circuit itself is very simple. Only real changes I made to it are making both the feedback and the primary resonant at the same freq as the resonator coil
(https://www.industrial-electronics.com/images/gern_ind_elec_f-305.jpg)

Basic setup, but instead of spark gap I am driving it with an oscillator.
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fwww.geocities.ws%2Fkaboooom2000uk%2Fmultiplersetup.jpg&hash=ea6bbde0e0bd5903471ee8da3d1291213f8ea53e)

In my version I use a tightly coupled "driver" coil made from about 100 turns of litz wire wound on a borosilicate glass lantern chimney, which serves as a former, the primary is about 20 or so turns of thicker litz wire I made using some magnet wire and a drill which sits on its own former.

The feedback winding is about 5 turns of more litz wire. I wound that on a acrylic tube which sits over the other coils for simple removal and modification.
(https://lh3.googleusercontent.com/bTUUYy7ZlEO8Af27Bm5xxQkNblct4bOLfXjsh7CmhHmc5_ex96GnXZJ4THcKxBVLZxt8Rdttn2p2n_LHqoXE5mFtNjGV9KYHi1iVWNGQiMwBFUkSL0hUaX1eFm-PLtUjRlS18Ey3s8DmUc4Z10bKAWdm-YDq_F_ut2QGkKTA0QE8kh-g5cLTQ-YgtDZ027QzWwYr8qYYtcjcQDZiwQ-WxIB2MZjW-xca10WcYpYERNcBlNegAV4Kwxkam9bNCqK_5LQfpFK1RuRSvAXSpyGRQgnOguGrBIQaRBLk8jgMXvYxxNhK2E_Xao9e894ByF9r8shbZhKt2Gjky3HgLIcd-efSKwSulKE9yKF32QlcP97VxoirfYnabbPHiWSgpJEgUAZKzQKKvAunzzFymPZVxy5V64Gxf9IPNOoORodWyM_TrmZnuFleiTV8y9C51y7-OQlcsLBmkYglWwkFmnhOJQ8o-oC2cA_1Ent4PDXVljDC9we-n3A0IUuMwzuHzLNeFQ1haiG22eUw6NQZzCmSo8Uj-lxPagbrYSIFzqU6okU9WotvPcleWi9p1h3w5HI3J5xPCcXOiu9G8AtkbhwxFKmeE5TGCbUMhqMO5jcjjw2rT4MxeIK6oBF1r-TEOmnPiD6FPN-SlZ1ZdsuQ6A484GhcmgFdUDyhyq-fihcYN8R1sRPS3cLuzDgmNj1k8UcY44bCFH5tMJCH2GtOm53SKKEp=w2859-h1353-no?authuser=0)

Power input was conceived using a pair of 650-115 transformers, I hooked them up backwards, to step up and the 115V windings were wired in series and fed with my 8A 240V variac. so I had about 1400V or so to play with at about 1KVA which is the limit of the transformers. This AC is then fed into a simple level shifter composed of a dual diode package and a 220uf 2500V capacitor, and 4700pf ceramic decoupler cap.
(https://lh3.googleusercontent.com/y5QoHS93oBALDqgJaX7zIvKOOoK4dLVpF8S4ikr4cjawHc5jkfYhtjxVpzrAG_z4u2r4Rq3h3GLDQ8iLCE4Ohy5fBTaS60jtaesnH9UIj0Gz3w-KKiQo2TaVEfB3xCiNKhOvbDqQAFXMf5N-nWhiGHI2EngtLuobEH-vtguLebKJmte4LURtOdgNmkAYfrqmLoAarFd1m5aBGjzhkvcOftFgWNtVVltRbDaGASYGKZGXsbqJyd94OZuAGLoMk7vXdUmM9WHQRZPgS3FSGC0UhOgiIENV-1cNOLaJSYFrfLIbq0ygbMV2qnYg0d0Rwm8ZleHQta8w0EOu0cfoSIQfFzl4WbuOcFld5dYuGjj65hYAtho6jHakRxmGN2ZQjzpxyC7HgWsV4Ia9uzVJ4PN15i65NsaCDkml0mkekC1PLQXGBelh2tpgjlkTGUDhx4Ca38jBaKrtu6Rd8AA3E-YuIv3URbFqQPXf5_xKueyOfbcJqQVtY9NopVzotLbuxqpQrZiFTQHJ4FvBwUknH3JWc647dwZDlBwGuNE1nq7AofEnE3F4TjIb9dpdBGVG2ksrkvNGmAPt5oznavc5fwSMXzYozf3B929eD2eHB9M3qEbGktnWL2xg40AfyHnhLdn6zbIt7M_iuIFn_01wtsFyUQBZG1kpKkFPYfF56GYIReKJSLXRCDZZ5BJX8wm3LkuMxR2ILhiNH9BY1hUxRouGOmS6=w672-h1418-no?authuser=0)

From the footage I took it appears to be working, I would say this because it appears the input voltage to the resonating coil is very low but then gains voltage the further up the coil I go.

I hope to get some more refinements done on this at some point but its been put on the hiatus while I play with solid state stuff. Namely my half-bridge universal driver.
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