This is something that i hope will generate a lot of responses. i am just about to embark on a new hi-fi project using ESP (sound.westhost.com) kit. I will be using toroidal transformers for the (individual) power supplies. As you know, transformers exihibit a large current surge at switch-on ( i think it's known as inrush ) and this is where the control thingy comes in. O.K. I want it to have a "soft start". I'm going to put my neck on the chopping block here, as i dont know if this will work: (please feel free to tell me that i'm completely mad, it wont be the first time)
My thoughts to combat this large inrush is to have a possible pre-start switch to control a circuit like a motor speed controller, which normally would use triacs, and have a digitally controlled potentiometer to emulate turning the speed (in this case power) from zero to full power in a time of say, 5 secs. This may be controlled with a 555 and/or cmos 4017 decade counter. Of course, the low cost of an 'axe to do this would make the project much more interesting and not that much more expensive. Also, please feel free to lose some sleep with this one, that way i wont feel quite as mad !!! Regards, wildbill.
Edited by - wildbill on 2/13/2006 8:25:22 PM
My thoughts to combat this large inrush is to have a possible pre-start switch to control a circuit like a motor speed controller, which normally would use triacs, and have a digitally controlled potentiometer to emulate turning the speed (in this case power) from zero to full power in a time of say, 5 secs. This may be controlled with a 555 and/or cmos 4017 decade counter. Of course, the low cost of an 'axe to do this would make the project much more interesting and not that much more expensive. Also, please feel free to lose some sleep with this one, that way i wont feel quite as mad !!! Regards, wildbill.
Edited by - wildbill on 2/13/2006 8:25:22 PM
