有關(guān)PFC的一些問(wèn)題,供大家參考
This time, I design a 240W output single output power , PFC was used L6561, it is a simply controller , easy to design, but the following item need to care:
1. Its driver current just only +/-700mA, if you design a higher power, you should add an additional driver circuit, totem pole circuit is a good and simply solution, and you need to care the layout. If not enough, easy to cause unstable.
2. For ZCD signa, the turn ratio need to care, as my experience: set it between 3:1 and 4:1 is a good idea.
3. For the CS, although this chip design in a LEB inside , but actually, it need a RC filter for it.Maybe need to paralled a cap with current sense resistor for EMI solution.
4. For the inductor, the litz wire is a good selection, if no this wire, can use thin wire to paralleled, please don\'t ignore it, in fact, the AC loss is higher than the DC loss, notice it. I test it, will inprove efficiency 2% or more.
Above just for your reference only, maybe, different application and layout, will cause different result.
Welcome you for discussion.
有關(guān)PFC的一些問(wèn)題,供大家參考
全部回復(fù)(6)
正序查看
倒序查看
@darkhorse96
老師,又見(jiàn)到你了!你說(shuō)的第四條我很關(guān)心,效率能提高2%,怪不得我以前做試驗(yàn)時(shí)用單線繞的,一會(huì)兒就燙手,我知道跟繞線有影響(集膚效應(yīng)),但沒(méi)想到這么大.還有由于CRM電感電流的峰峰值是CCM的兩倍,因此它的磁心的損耗比CCM大的多.
For PFC inductor design
Yes, you are right, the skin effect is an important and basic consideration for the inductor design, but the Proximity Effect is a much more important consideration for PFC inductor especial in DCM PFC convertor.
Yes, you are right, the skin effect is an important and basic consideration for the inductor design, but the Proximity Effect is a much more important consideration for PFC inductor especial in DCM PFC convertor.
0
回復(fù)
@arthur.deng
ForPFCinductordesignYes,youareright,theskineffectisanimportantandbasicconsiderationfortheinductordesign,buttheProximityEffectisamuchmoreimportantconsiderationforPFCinductorespecialinDCMPFCconvertor.
你好,請(qǐng)問(wèn)一下PFC中輸出功率是怎么算出來(lái)的?謝謝!
500) {this.resized=true; this.width=500; this.alt='這是一張縮略圖，點(diǎn)擊可放大。\n按住CTRL，滾動(dòng)鼠標(biāo)滾輪可自由縮放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/35/1133342399.gif');}" onmousewheel="return imgzoom(this);">
500) {this.resized=true; this.width=500; this.alt='這是一張縮略圖，點(diǎn)擊可放大。\n按住CTRL，滾動(dòng)鼠標(biāo)滾輪可自由縮放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/35/1133342399.gif');}" onmousewheel="return imgzoom(this);"> 0
回復(fù)
@小三
你好,請(qǐng)問(wèn)一下PFC中輸出功率是怎么算出來(lái)的?謝謝![圖片]500){this.resized=true;this.width=500;this.alt='這是一張縮略圖，點(diǎn)擊可放大。\n按住CTRL，滾動(dòng)鼠標(biāo)滾輪可自由縮放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/35/1133342399.gif');}"onmousewheel="returnimgzoom(this);">
是后一級(jí)d2d的輸入功率,也就輸出功率/效率
0
回復(fù)
