Stoneridge Engineering Home |
Hi Dave, Congratulations on finding the baby pig and the transformer laminations. You have an excellent ballast core - a 2" x 4" core can easily handle 3 kVA. And your pig should easily handle intermittent overloads of 100%. Since you don't plan to use high temperature magnet wire in your ballast, I'd suggest using high temperature #12 AWG THHN (90 degree C) wire. This has PVC insulation housed within a nylon jacket that will help prevent insulation flow/failure at higher temperatures. The ballast should be good for intermittent 3 KVA duty from a 240 volt supply. Your large core size (2" x 4" or 8 square inches) will give you about 1 turn/volt (with no air gap), so using 240 - 300 turns should be in the right ballpark. You'll need to adjust the air gaps between the E and I core pieces to get the current setting you want - use thin sheets of paper or Mylar. As you are winding the choke, you could add taps to provide a convenient selection of current levels for a given gap setting. For example, suppose you are going to wind a ballast that uses 300 total turns. If you make taps at about 105 turns, 120 turns, 150 turns, and 210 turns, you'll get approximately linear current tap settings (100%, 75%, 50%, and 25% of maximum). Using the entire 300 turns will give you ~12.5% of the maximum current setting. And, if you use #10 AWG for the first 120 turns and then use #12 AWG for the remaining turns, you'll be able to push the higher current ranges of the choke with considerably less heating. Good luck and play safely! -- Bert --
: Hi, I have constructed "E's & "I's" for a vari gapped
: choke ballast. The center where the windings will be has a 2" by
: 4" area,and 'bout 5.5" winding length area, with about 2"
: winding windows (I can email a pic if you want ). I have just found a baby
: pig , 1.5 kva , and would like to limit to about 9-10 amps max as not to
: burn it up. Would 240 turns be about right do ya think ? Also, as I never
: plan on exceeding about 3kva, would #12 wire work ok ? I was just planning
: on using the plastic insulated type, not magnet/motor wire. Thanks for any
: help you can give me!!!!!!!dave
:
Message Thread
« Back to index | View thread »