A line filter as the one depicted in my ASCII graphics will in no way take away or otherwise influence the 100Hz line cycles! It will only prevent high-frequency disturbances from either side of the filter to pass to the other side of the filter. This kind of filter by definition cannot significantly influence the power consumption of the circuit.
A high-voltage capacitor - which is not present in Declan's circuit - _after_ the full-way bridge rectifier would suppress (or at least smoothen) the 100Hz oscillations of the rectified mains voltage... But this would not be called a "mains filter". Uwe. > Hi Declan, > That this kind of device did not have a mains filter is not > extraordinaly. My cleaner has neither. So the ultra sonic wave is > modulated by the 100 Hz half cycles of the mains. I do not know > wether this has any effect on the cleaning capacity. At least this > saves space under the can. But adding a filter can perhaps change > the dissipated power of the power amplifier/oscillator. So, be > carefull! > Harry >> >> Well, I did the tests and am reporting back. We can argue about it later >> >> 1. BU225s were worse than BUX80s (i.e. more noise) >> >> 2. They wiped out the medium wave (560 -1600khz) and did not have the >> more limited effect of the BUX80s which notched out local stations and >> then just annoyed on the rest of the waveband >> >> 2. Moving mains point did not solve the problem. It reduced it. >> >> 3. Moving to Battery power more or less did solve it. The radio became >> quite understandable, with noisy patches when the ferrite rod in the >> radio was end on to the interferance. So it was directional. >> >> This seems to confirm >> >> a. That transistor equivelants were a bad idea >> b. That the majority of the noise is coming through the mains. >> c. That a mains filter might have been a good idea after all. >> >> /knocks himself on the head >> >> BTW, These diodes are a mains full wave rectifier, but have NO >> electrolytic smoothing it. That's pretty unusual on a single phase. >> That's where I'll start. I know, I know, electrolytics are useless at >> hf, but it might keep the voltage up across those diodes. >> >> -- >> >> With best Regards, >> >> >> Declan Moriarty. >> -- >> Author: Declan Moriarty >> INET: [EMAIL PROTECTED] >> >> Fat City Hosting, San Diego, California -- http://www.fatcity.com >> --------------------------------------------------------------------- >> To REMOVE yourself from this mailing list, send an E-Mail message >> to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in >> the message BODY, include a line containing: UNSUB CHIPDIR-L >> (or the name of mailing list you want to be removed from). You may >> also send the HELP command for other information (like subscribing). >> -- Author: Uwe Zimmermann INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
