heady 0 Report post Posted May 29, 2008 The centre tap of the first transformer is connected the supply earth. Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 29, 2008 The centre tap of the first transformer is connected the supply earth. Alright!! Thanks a million heady for answering my endless question. Time for some trans shopping next week. Share this post Link to post Share on other sites
heady 0 Report post Posted May 29, 2008 Share info only leh, I not expert. Let's see who can get this tweak working first and with what equipment. Then post review ok? Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 29, 2008 Share info only leh, I not expert. Let's see who can get this tweak working first and with what equipment. Then post review ok? haha sure thing! i planning to do 1 for usb monica 1st. will work on SOHA when my jisbos boards arrive Share this post Link to post Share on other sites
mouz 0 Report post Posted May 29, 2008 I m definitely gonna be watching this thread see how you guys progress. Will be good knowledge for a newbie like me as I'm looking for a good power source for a SOHA build too BTW, any idea wat value schottky diodes it's using? Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 29, 2008 I m definitely gonna be watching this thread see how you guys progress. Will be good knowledge for a newbie like me as I'm looking for a good power source for a SOHA build too BTW, any idea wat value schottky diodes it's using? the schottky diodes are acting as a bridge rectifier to convert the AC to DC. schottky are used due to its fast response time i think(thats what my brother told me). please correct me if i am wrong. Thus the value of schottky would be dependent on the output trans you use. Just go way above specs of the trans will be safe i think Share this post Link to post Share on other sites
mouz 0 Report post Posted May 30, 2008 (edited) tats new to me, I didn't know schottky diodes has such a function, converting AC to DC. Since SOHA's using 15V, I suppose we can use the diode found below? http://sg.farnell.com/9843787/discretes/pr...onductor-1n5817 Edited May 30, 2008 by mouz Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 30, 2008 (edited) tats new to me, I didn't know schottky diodes has such a function, converting AC to DC. Since SOHA's using 15V, I suppose we can use the diode found below? http://sg.farnell.com/9843787/discretes/pr...onductor-1n5817 AC->DC rectifier are actually 4 diodes arranged in a certain manner to give it a full wave rectification.In fact, LED would be able to perform the same function. So long its a diode, its okie. schottky is used due to its response time i think. Yup, i think the diode is okie. Edited May 30, 2008 by Cloud Share this post Link to post Share on other sites
mouz 0 Report post Posted May 30, 2008 Thanks for the advise , Planning to try out the SOHA with a normal 15v AC-AC adaptor or the toroid transformer first before moving to that. Any idea if this would work with a toroid transformer? Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 30, 2008 Thanks for the advise , Planning to try out the SOHA with a normal 15v AC-AC adaptor or the toroid transformer first before moving to that. Any idea if this would work with a toroid transformer? hmm i not so sure about toroid trans. should ask heady the guru Share this post Link to post Share on other sites
heady 0 Report post Posted May 30, 2008 tats new to me, I didn't know schottky diodes has such a function, converting AC to DC. Since SOHA's using 15V, I suppose we can use the diode found below? http://sg.farnell.com/9843787/discretes/pr...onductor-1n5817 SOHA needs 15V AC and not DC so you don't need a bridged rectifier made up of diodes. Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 30, 2008 SOHA needs 15V AC and not DC so you don't need a bridged rectifier made up of diodes. Ah.. missed out that point. The diagram is actually for DC source. For SOHA, just ditch the rectifiers. Share this post Link to post Share on other sites
mouz 0 Report post Posted May 30, 2008 OIC, for DC throw in the rectifiers, for AC its without rectifiers since trans are already outputting AC. I suppose throwing in a bipolar cap is a good idea for AC output too right? Share this post Link to post Share on other sites
Cloud 0 Report post Posted May 30, 2008 OIC, for DC throw in the rectifiers, for AC its without rectifiers since trans are already outputting AC. I suppose throwing in a bipolar cap is a good idea for AC output too right? why would you want to have a cap for the current? Share this post Link to post Share on other sites
mouz 0 Report post Posted May 31, 2008 (edited) Lower impedance? but it's optional, Heady's link shows the setup using one for tat purpose, it says 'the optional capacitor provides an even lower impedance path for noise'. But is it neccessary for AC? Edited May 31, 2008 by mouz Share this post Link to post Share on other sites