Forums
New posts
Search forums
What's new
New posts
Latest activity
Members
Registered members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Audio and Video Talk
Valves / Vacuum Tubes
EI VS C-Core for PP transformer question
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support AVForums:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="Ampdog" data-source="post: 596828" data-attributes="member: 144"><p>Steerpike and OP,</p><p></p><p>Yes, the air-gap. Not to deviate, but I discovered the hard way that one has to be careful in assembling C-cores. The slightest dirt in the gap and down goes the inductance! When sliding the core into a fully-wound bobbin (and that is another story for later!), the sharp steel edges can scrape some shavings off the bobbin or winding outside cover - air gap! I had a particular transformer measure in at 44 Hy, disassembled, cleaned thoroughly and re-measured at 55 Hy!</p><p></p><p>After that I carefully filed the sharp core edges very slightly to take the sharpness off (also core sides), to ease the sliding in. Some light lubricant can be smeared on edges but very little! One can also clean the C-butt ends with high grade sandpaper until they shine. With the high-? of grain-oriented steel cores this can make a difference.</p><p></p><p>2wice,</p><p></p><p>I did not mention earlier (don't know how detailed you want to go) that an intermediary between ordinary E-I cores and C-core are E-I stampings from grain-oriented steel sheets, with the grain direction following the main limbs' direction. Thataway one gets something with grain-orientation advantage in most of the core. However, this is not often used as far as I know.</p></blockquote><p></p>
[QUOTE="Ampdog, post: 596828, member: 144"] Steerpike and OP, Yes, the air-gap. Not to deviate, but I discovered the hard way that one has to be careful in assembling C-cores. The slightest dirt in the gap and down goes the inductance! When sliding the core into a fully-wound bobbin (and that is another story for later!), the sharp steel edges can scrape some shavings off the bobbin or winding outside cover - air gap! I had a particular transformer measure in at 44 Hy, disassembled, cleaned thoroughly and re-measured at 55 Hy! After that I carefully filed the sharp core edges very slightly to take the sharpness off (also core sides), to ease the sliding in. Some light lubricant can be smeared on edges but very little! One can also clean the C-butt ends with high grade sandpaper until they shine. With the high-? of grain-oriented steel cores this can make a difference. 2wice, I did not mention earlier (don't know how detailed you want to go) that an intermediary between ordinary E-I cores and C-core are E-I stampings from grain-oriented steel sheets, with the grain direction following the main limbs' direction. Thataway one gets something with grain-orientation advantage in most of the core. However, this is not often used as far as I know. [/QUOTE]
Insert quotes…
Verification
Post reply
Audio and Video Talk
Valves / Vacuum Tubes
EI VS C-Core for PP transformer question
Top