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</o:shapelayout></xml><![endif]--></head><body lang=FR-CA link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoPlainText>Hi all,<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>I’m using this type of stepup voltage regulator to generate +15vdc and +30vdc<o:p></o:p></p><p class=MsoPlainText>From an incoming single +9vdc power adapter.<o:p></o:p></p><p class=MsoPlainText>These BUCK’S converters generate very good regulated voltage outputs but I noticed<o:p></o:p></p><p class=MsoPlainText>that on power up they ‘need’ to rise up to around +48vdc<o:p></o:p></p><p class=MsoPlainText>Before settling down to their trimmed voltages.<o:p></o:p></p><p class=MsoPlainText>Well these 2 voltages will supply a DSP module @ +15vdc (not more !!!)<br>and a dual opamp TL072 that has a maximum allowed supply voltage of +/- 18vdc (36vdc overall).<o:p></o:p></p><p class=MsoPlainText>I tried putting a 16v zener diode in parallel with the trimmed +15vdc<o:p></o:p></p><p class=MsoPlainText>But the BUCK goes wild (input current rise up to around 2.5 amp and stays there !!)<o:p></o:p></p><p class=MsoPlainText>I also tried to put an RC circuit at the input (33ohms + 100uf) of one of these BUCKs<o:p></o:p></p><p class=MsoPlainText>But again the modules rise its input current to ‘try’ stabilize the regulation..<o:p></o:p></p><p class=MsoPlainText>Even with 100ohms resistors and 16v zeners.. the BUCKs won’t start<br>and finalise their outputs (inrush current installs).<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>So.. I’m stuck with this problem..<o:p></o:p></p><p class=MsoPlainText>Any possible solutions ???<o:p></o:p></p><p class=MsoPlainText><span style='mso-ligatures:none'><img width=1302 height=1286 style='width:13.5625in;height:13.3958in' id="Image_x0020_5" src="cid:image001.jpg@01DA60CD.A2F81360"></span><o:p></o:p></p></div></body></html>