----- Original Message ----- From: "Russell McMahon" Subject: Re: Coil winding > Are you matching the "dotting" shown. The dots mean that if the two Russell makes a lot of good points. A couple of others ... Is your core ferrite? The article seems to give precious few details, but if you happen to have a powdered iron core it may look like the ferrite core but won't give you nearly as much inductance. Have you played with the wire size? There are quite a few turns on a small core, so the wire size needs to be quite small. But the small wire size plus lots of turns leads to higher resistance, and if your wire size is too small you might have too much resistance. Again, a quick look at the aticle seems to reveal little to help. Russell mentioned the dots, and that should be re-emphasized. Most of the time when this type of transformer doesn't work it's because the dots were overlooked. But then, most of the time you know the wire size and the core mix, neither of which are mentioned. --McD -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist