---

 

좋은 글이있어서 여기에 소개합니다. 

 

R-core OPT 에서 core 구조에서오는 " Balance -Leakage flux  감쇄에 절대적으로 중요한 요소" 는 모르고 있습니다.

아마도 저혼자만 알고 있는 OPT Knowhow 같습니다.   

 

 

http://sound.whsites.net/valves/design2.html

 

http://sound.whsites.net/xfmr2.htm

 

 

 

 

2 - Output Transformers -일부 발취

 

Figure 2 - Interleaving and Connecting Multiple Windings

Figure 2 shows the basic arrangement, using four primary sections and three secondaries. While the secondaries are shown in series, they may also be connected in parallel, depending on the impedance. The most important part of winding any transformer is to ensure that the 'window' (the space allowed for the copper) is full - as full of copper as it can be. This minimises resistance and losses, but naturally some space must be allowed for inter-winding insulation. This should be as thin as possible, but must be able to withstand the maximum possible voltage without failure. The requirements are conflicting, because you need ...

1. As many turns as possible for high inductance
2. The lowest resistance you can get to minimise losses and temperature rise
3. Very low leakage inductance for good high frequency response
4. Low inter-layer and inter-winding capacitance
5. Low core flux density to minimise low frequency distortion
6. High insulation breakdown voltage for long-term reliability

.

It is extremely hard to even get conventionally wound output transformers to have equal resistance on each half, because the length of wire (and therefore its resistance) needed for a specific number of turns is shorter for the inner windings than for the outer windings. This usually results in unequal resistance in each half of the winding, and therefore unequal losses. While these inequalities are usually not serious, they usually do mean that one side of a push-pull amplifier clips earlier than the other, and cause some distortion at lower levels. 

 

---PP OPT 의 Unbalance 를 지적하고있지만 Core 의 모양 - KDK가 지적하는 Leakage flux 관계는 모르고 있습니다---  

 

Figure 3 - Pi Windings For An Output Transformer

 

 

시간 있으시면 2 - Output Transformers 전체를 읽어보십시요

 

Output transformers are certainly not magic, but the design of one that gives excellent performance over the entire frequency range is as much an art as it is a science. There are too many intangible factors, and too many conflicting requirements to be able to simply jot down a nice formula that covers everything.

 

Most of the old artists who used to know all the tricks and could design a great transformer on the fly have now passed on, and with their passing a great deal of valuable knowledge has been lost.

 

on the fly -- 영국사람들이 많이쓰는 표현으로 "손쉽게-얼렁뚱땅 - 별로 따지지 않고 --

passed on 죽었다 =  미국서는 Passed away 

 

 

제가 하고싶은 말입니다 

 

 

눈감고도 최고수준의 OPT 를 만들던 장인들은 이젠 모두 이세상을 떠났습니다 

이들이 갖고있던 대부분의 핵심 Knowhow/정보는 이들과 더부러 영원히 사라졌습니다