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Title: Help needed Post by: Bacra2k on March 03, 2006, 10:55:44 22:55 Hi
I need a circuit that can convert 220VAC to 90 VDC 500mA without transformer any help are welcome Salu2 Title: Help needed Post by: Parmin on March 04, 2006, 03:47:37 03:47 Yeah right 45watts and no transformer...
I would like to have one too :) Seriously, at least you would need an inductor, the result would be a pretty complex circuit but is doable. I would rather use a small transformer.. Title: 90 Volt Power Supply Post by: Fred Murn on March 05, 2006, 04:31:57 16:31 Not a good idea. Even if you resort to a voltage divider technique like they used back in the days of vacuum tubes (remember those ??) the heat generated would be intolerable,not to mention the risk because of the lack of isolation from the mains. Use any step up/down transformer then appropriate division or multiplication after rectification.
Fred Murn Title: Help needed Post by: Parmin on March 05, 2006, 10:10:46 22:10 GAH!!! 90V 500mA voltage divider !!! Strewth!!!
*** D A N G E R ! ! ! ***** Dont do that ! it'll either kill you or burn down your house!! Title: Help needed Post by: Bacra2k on March 07, 2006, 06:13:47 06:13 Thanks to all for his answers I have solved the problem with a simple dimmer circuit This does not generate heat and it is stable for the required purposes About of the risk because of the lack of isolation from the mains is to take in mind, may be need a insulating transformer. Salu2 [/font] Title: Help needed Post by: max on March 07, 2006, 06:44:20 18:44 You can also use an ac capacitor to drop the voltage
xc = 1/(2fc * pi) Title: Help needed Post by: Parmin on March 07, 2006, 10:11:54 22:11 Quote from: Bacra2k Thanks to all for his answers HIS? Oh you've broken my heart you chauvinist you!!! :) [/left] [/font] |