1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

help verify parts will work for me

Discussion in 'High Voltage' started by lokeycmos, Dec 19, 2011.

  1. lokeycmos

    lokeycmos New Member

    Joined:
    Oct 17, 2011
    Messages:
    188
    Likes:
    0
    im getting ready to order mmc caps and parts for terry filter. i would like someone more experienced to verify i have picked out the right parts/values/voltage ratings. terry filter schematic is here: http://4hv.org/e107_files/public/1274765667_480_FT89658_terry_fritz_r-c_filter.jpg

    for terry filter im ordering parts from digikey.com.

    terry filter will need the following 4 parts:

    1K 100 watt: digikey # FVT100-1.0K-ND correct value, but is wirewound. will its inductiveness affect the performance? will this handle the high voltage?

    10Mohm .5 watt self explanitory

    1800 volt MOV: digikey# P7227-ND does this look right?

    .0033uf 1600v: digikey# P10501-ND this has a 1600v dc rating but no AC rating. will this work with AC in terry filter?


    now for my MMC the cheapest caps i found here:
    http://www.easternvoltageresearch.com/parts_caps.html

    Cornell-Dubilier CDE 942C20P15K-F has a 2000 volt DC rating AC rating is usually lower than dc for capacitors . from what ive gathered these are the cap of choice for Tesla coils. tesla coils work on AC. will these still work? i need 8.6 nF with over 22kv(peak) rating. i could put 17 in series for 34kv and 8.824 nF

    thank you for verifying my parts before i order.
     
  2. lokeycmos

    lokeycmos New Member

    Joined:
    Oct 17, 2011
    Messages:
    188
    Likes:
    0
    the first link is dead. here is a pic of the schematic.for those that dont know, the terry filter is used to protect the neon sign transformer from damage from high frequency/high voltage from going back into it. i chose this because of its good history from other users.
     

    Attached Files:

  3. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

    Joined:
    Oct 30, 2010
    Messages:
    9,906
    Likes:
    1,094
    I didn;t look at your parts closely, but I did notice the missing safety gap. Newark has some to 7.5 KV. You can probably put them in series, I have used 1000 V gaps before.

    http://www.newark.com/jsp/search/br...ch&Ntt=gas+discharge&Ntx=mode+matchallpartial

    This thing will probably have to be built using teflon or ceramic standoffs.

    Those sorts of resistors generally can be used, but I would mount the mounting things on ceramic standoffs as well. Fiberglas makes a nice substate to make the base out of. Use Locktite 222 if you use screws and crimp terminals.

    I would try to ascertain the voltage rating of the resistors by looking on their website and/or calling the manufacturer and then create a series combination of the voltage ratings. Generally, the longer the resistor the higher the ratings.

    I've works on stuff that had a 15 kV, 1 Amp shunt regulator and 100 kV at 0.1 A power supplies. I would also create a safety as best as you can. e.g. Locked door, safety switches, a power switch that uses a key etc.

    Teflon turret terminals http://www.newark.com/jsp/search/br...ions=false&ref=globalsearch&_requestid=351098 might also be used to put yur MOV's together.

    Pay attention to distances and the dialectic strength: http://en.wikipedia.org/wiki/Dielectric_strength of the materials and air.

    I didn't comment specifically on your parts. Maybe later today.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. gary350

    gary350 Well-Known Member

    Joined:
    Dec 28, 2005
    Messages:
    1,097
    Likes:
    53
    Location:
    Murfreesboro, TN 37129 USA

    Get 2 ferite toroid about 1.5" ID wind each with 40 turns of #14 insulated house wire. Put a choke coil on each HV output terminal of your neon. You don't need the terry filter. 60 Hz will pass through the choke but the high frequency high voltage will not come back.

    The mmc caps works great be sure to buy the correct caps and over voltage rate it a minimum of 40% above your transformer voltage.

    Build a variable speed vacuum fan RQ spark gap, (VSVFRQSG) with a variac speed control. This thing is amazing you can dial in the correct fan speed for maximum arc length. Move your primary coil tap to find the best location for your top load. If you change your top load you must retune the primary.

    http://i67.photobucket.com/albums/h292/mikeweaver/gap3.jpg

    http://i67.photobucket.com/albums/h292/mikeweaver/gap4.jpg

    http://i67.photobucket.com/albums/h292/mikeweaver/gaps5.jpg

    http://i67.photobucket.com/albums/h292/mikeweaver/gap2.jpg

    http://i67.photobucket.com/albums/h292/mikeweaver/gap1.jpg

    You also need a variac on the input of your neon. This is extremely helpful when tuning the circuit for maximum output. Turn the voltage down so the output at the secondary is only about 1 inch long sparks. Next turn the fan speed of the spark gap you will notice the 1" output spark get longer and short as the fan speed changes. Find the best fan speed for max output then turn up the voltage on the neon.

    Be sure to put a strike rail around the outer edge of the primary about 2" above the primary. Connect the strike rail to ground. If any HV arcs try to strike the primary they will hit the strike rail this protects your neon from HV. Look at the strike rail in the TC on the right side of the LAST PHOTO. The strike rail is 1 turn of 1/4" copper tubing the ends are "NOT" connected together they need to be about 1/2" from touching.

    Here are some pics of some of my TCs. My 10" TC makes 12 foot arcs around the 3 ft sphear it produces a 27 ft circle is sparks in my back yard.

    http://home.earthlink.net/~gary350/tc3.jpg

    http://home.earthlink.net/~gary350/tc10-4.jpg

    http://home.earthlink.net/~gary350/tc2.jpg

    http://home.earthlink.net/~gary350/tesla1.jpg

    http://home.earthlink.net/~gary350/tesla2.jpg

    http://home.earthlink.net/~gary350/sphere2.jpg

    http://home.earthlink.net/~gary350/tc4.jpg
     
    Last edited: Dec 21, 2011
  6. lokeycmos

    lokeycmos New Member

    Joined:
    Oct 17, 2011
    Messages:
    188
    Likes:
    0

Share This Page