--Message-Boundary-12757 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body > > Also I think your topology would require the MOSFETs to switch > > current in > > both directions (they are fundamentally not AC switches), but not > > sure if I visualize your circuit correctly. > > *** Useful application of MOSFETS as AC power switches *** Yeah I know, that's why I said "fundamentally". I was trying not to throw too much into it and confuse things. Two MOSFETs make a perfectly good AC switch. Cool circuits Russell, I'll keep them for reference. The attached circuit shows a way of switching AC with two cheap optocouplers and two schottky diodes (sorry wrong diode symbol). I did this recently because I needed to supply some isolated "clean contacts" to switch a circuit of unknown polarity. I first used a 10A relay which cost NZ$1.00 (US$0.50), but worried about not having enough wetting current (only switches 5VDC at a couple of mA). I considered a photo MOS kind of optocoupler but they run in anywhere around $NZ6-$12. A reed-relay is the good but around NZ$3.50. The circuit shown is little over NZ$1.00 including the two schottky diodes (sorry wrong symbol). Voltage drop when "ON' is about 0.35V. -- Brent Brown, Electronic Design Solutions 16 English Street, Hamilton, New Zealand Ph/fax: +64 7 849 0069 Mobile/txt: 025 334 069 eMail: brent.brown@clear.net.nz --Message-Boundary-12757 Content-type: Image/GIF; name="ACoutput.gif" Content-disposition: attachment; filename="ACoutput.gif" Content-transfer-encoding: BASE64 R0lGODlhWAGRAPcAAAAAAAAAMwAAZgAAmQAAzAAA/wAzAAAzMwAzZgAzmQAzzAAz/wBmAABm MwBmZgBmmQBmzABm/wCZAACZMwCZZgCZmQCZzACZ/wDMAADMMwDMZgDMmQDMzADM/wD/AAD/ MwD/ZgD/mQD/zAD//zMAADMAMzMAZjMAmTMAzDMA/zMzADMzMzMzZjMzmTMzzDMz/zNmADNm MzNmZjNmmTNmzDNm/zOZADOZMzOZZjOZmTOZzDOZ/zPMADPMMzPMZjPMmTPMzDPM/zP/ADP/ MzP/ZjP/mTP/zDP//2YAAGYAM2YAZmYAmWYAzGYA/2YzAGYzM2YzZmYzmWYzzGYz/2ZmAGZm M2ZmZmZmmWZmzGZm/2aZAGaZM2aZZmaZmWaZzGaZ/2bMAGbMM2bMZmbMmWbMzGbM/2b/AGb/ M2b/Zmb/mWb/zGb//5kAAJkAM5kAZpkAmZkAzJkA/5kzAJkzM5kzZpkzmZkzzJkz/5lmAJlm M5lmZplmmZlmzJlm/5mZAJmZM5mZZpmZmZmZzJmZ/5nMAJnMM5nMZpnMmZnMzJnM/5n/AJn/ M5n/Zpn/mZn/zJn//8wAAMwAM8wAZswAmcwAzMwA/8wzAMwzM8wzZswzmcwzzMwz/8xmAMxm M8xmZsxmmcxmzMxm/8yZAMyZM8yZZsyZmcyZzMyZ/8zMAMzMM8zMZszMmczMzMzM/8z/AMz/ M8z/Zsz/mcz/zMz///8AAP8AM/8AZv8Amf8AzP8A//8zAP8zM/8zZv8zmf8zzP8z//9mAP9m M/9mZv9mmf9mzP9m//+ZAP+ZM/+ZZv+Zmf+ZzP+Z///MAP/MM//MZv/Mmf/MzP/M////AP// M///Zv//mf//zP///wAAAA0NDRoaGigoKDU1NUNDQ1BQUF1dXWtra3h4eIaGhpOTk6Ghoa6u rru7u8nJydbW1uTk5PHx8f///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACwAAAAAWAGRAAAI/gDLCRxIsKDBgwgTKlzIsKHD hxAjSpxIsaLFixgzatzIsaPHjyBDihxJsqTJkyhTqlzJcuW1hC8Rxjw402DNgjcJ5hy4U2DP cj+DwhwqkyhNozaR4lSqkylPpz6hApUqtKjVoy2zat3KtavXr2DDih1LtqzZs2jTql3Ltq3b t3Djyp1Lt67du3jzph3AdwDBvn7/8tVLuLBhgYHLJf47MPHiw5Aju3V8kDJiyZjVVsXKOelV z52XFgRscPDMvk8/iw7dVHVr1qlhR3UdG7Tt1bdf566Nu7du32ofA348WnFCy8YzK18uUrjD wMQvS08OEjni6MxRCx48GjvzksMb/j8Xf517Y/PVyU//Xpx6+/XsVwrXvha59+/W1d+PD/44 W/v08ZcfeqTxt1V+Z9mnXnwIUteggSkFiJCEFBIooUUKwoefhtM9CCFYGTqo34IXVbgfZibO d+KHJQ7n4osLRWeZeR6yaCNFm+02m2xTyfTij4D9JGOPfhXpU4G8/aZkkkzuqGOPPOYInJNT QvmklEtSmaWVVdYn0ZCCdejejWSytyJjpaUp5pgZLWZdgOERhiSJisFp4YVlQnRmeTTOCSed GLoJ3Ygc5vWme2CKmCdGe5JlpHiPvtcoXCE2GOKiFU0a1qCQsikoeob+uZ6J22mKaaHBIQmd cxMWBiCe/5cCemqMxwFp663NoYmommzaVWllhCo6q0NsDMBGqxyZ+pCb+vkJKl5+NgsqqcMS Wywbx/KqkbLVlollk1xu+S22uNKm5XlAUqWuueGC++258LYb77vy1kvvvXKRiy2wySaUbbfb esctwAhdi+xG3v2rkDDfCeOww8li9yzBJdZ668Uu+ssQxMwx/NHEeFKcKVcKJ+RxdxinrPLK LM95ckfPzilyxVuVjNDLssq12MM4M6rixDNPNPBGNh/Uc69zYXd0pp+GHHREQ2tUtEFHRy3W zgMtTVGfcX7l9F1WYzQ1QQ9r62tBZUfMp8wWYTv2eKieXfPIhoJX5I9Su/02rf66KoQvu3+X emHgT+pteLEtd+3uulgl7vjjkLt4+OSHq/zek2ix2tZ9YWMotN11wpiR4XTnHCGsKCuk+X+q Lwt06VCDHrriF7lNM9LykUhgzqt76Z/rPsfN90hcs912m6/nPuquqPYeXOvjRT3YwJ2r3nTy Eu1NqagqQm96WatafnmLQ1dfK8rYR6T9W5GuHazZ5p/kWMpmt8io7KVytP5kHDLb/PjPQ5et 1PS150gPf9vRn5zo1L3ffc9R6BNd39LHEAoOrzkSq97+DOS8vZQGb62T3gFJ8joNuoRxV0Kh dGJCHMJVCV8yyti5/OJC7sAwSioUl1TG5sItZQ6AHv6sjPH6Frzb1WWDAXQfuvIHP7OkjYgJ 9F7A7kc1uCAxcxILFoI66JWT4YxzF5yiEQXCMbdc0Szt09Wq3gef+IHki2u7GAbLh7ZyaO0s Z4Rgr5gVKeNxESw9Cx/9QjI9z2WNjFb0lczmI6YsQjEsVZOiSbjDKT2RjWdvySMam7imRAlv K0sD4+mWGLsqZhJ5bvwcAEXlKSB2EZOPfCDxLPjIO9ZsXwfRpBpd5coESfJ0tJTlV0hnEF22 sSE9XBzg1MTCFC6zYJRDHOScicOrRC5l0cymNrfJzW6KL2c/+WEsTaLLVGrFnCAhZkGMOSZ0 ZuWPJSmnXtz5Edvlkoq4S/9aL+MJO7mxZWzsLI9h4EkSedatLQCtFkFHYlBomVFjw1qoSMp5 zYpalHZpSWhE91nQp3lFo7OSaEgC6lGpQTSkHGVoSUl2UpQkc145lKAyq3nPZ9KUmjh9YQ5n mlOCgLSnPKUUS1eqlZ9udG5bk1YwXTUtOxWwmC09alFL50kzFaqqDDEqSpGqyj1CyFL8eohW T0XPhjSUOGUVZzuxmtWobnWqST3mh8A6ToWMFVNpXchZU4qiq/IVqgUjWF7tGii0sihF9TOr W8k6VKK25K4jeam9dooqyf6Eh5SdrE2BCtPN6pRdkLUsXQa7WMeeBLJ5Im1gjfimOy21PhdC q1P+BVcO1JZJtTVlWpiEVSN/8vGRsbItmXAL2KT+NlHEjZAWARXc0i4quT6l23G1NcS6RGtU TW2aQIR7I+gOhKL0WeM4vZurDvmRjZfh7mRill3BDZKc+BRWKz8p1DV51b6UUe/mlodf95br tPF91Z0Gysr5tTeK+mVd/9j4TQCbliUJ3oho23MNw55GOxf+70uiI1nMelaHHw4qiG/6WR6F NrPh9MiAHOjf86r0wQ0pYfacqzO5hvWDMv1rRdZny8LwrMd6yuCMVxuqnwkqRjL8nRu1V0bl AFloMdRUhBlU3Sh2hMdCvKiWr0m26sj2tVOm8pmeOhEsJ1afWXuiGAX+KGUa39aAr1Xsxm7s zzoi7HptJnJ3W4YSM+vYd4gM9JpzLOfc7pll9BXbxpqcaAWn+cnAm12V9bxOwVawo3F1KAnv Rui2UtokEybxlrxzmhIXLppcNrWqW7PlVm/ZuaGOy5gbPclfqsRUZZ0eCE0KsD2RGSWijHGc bR1j2e16dJaGM4iIPSER0vrPuo2jCXsNZ/Lu09f5NGC2w+hl9yqQ2rKW9gChbT06bjqC3+6W tQ0p6XHX9UsjnCWOp63uGrP52NL5tfXiS8gop1uh9r43Ro9svzF2W4j/lir75o3R4jjb4B8T WMJBjeKKH4yzmhX1U6KMpJ3QUIU2VBeHLa7/8Xh5uOT1AvTCs4y96g373QhN9lnU3LyWwyze XT4luJ14yLruJ34vpxOj10LSzKz7IXBs938jbu5DQjosRe+rWgIp7nT1e9tS9NjTwRJ1yRx9 zmd+NvLy/aVL0lwtXY/M1xd28bBfXaCltPNDu2UwJ8LSdN7VN6C2Pky6XyvtwGa23V67dkWr 5LLdTLziF8/4xjs+1SPGeIZd3RfHW77xJMccWtS534PCOKO4XLmmP096t9e39KgXu1pTX/rC t4n1qae87FcG+9rb/va4z73ud4+WWK9axMDvLMp9H/nfC1/ymTd+xjXP++Y7//nQj770p0/9 6lv/+tjPvva3z/3uHnv/+3khfvCXr3zxH7/8yS+++sdvfvL7EPzwb0hAAAA7 --Message-Boundary-12757-- -- http://www.piclist.com#nomail Going offline? 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