tag:blogger.com,1999:blog-35901825.post1383951546060256896..comments2024-03-19T06:03:40.451+10:00Comments on marxy's musing on technology: Variable DC regulator V1Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-35901825.post-53888538747310815452007-12-27T12:59:00.000+10:002007-12-27T12:59:00.000+10:00Yep, I built a supply for my CB years ago like tha...Yep, I built a supply for my CB years ago like that too, with a 2N3055. It worked well, and I still have it. The the 2N3055 is a pretty ancient device and it has poor gain especially with large collector currents, I had a second smaller PNP transistor in there in as a Sziklai pair to supply the bias current needed.<BR/><BR/>The TIP range has some devices with better gain at high currents. WhichAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-35901825.post-5804510149489048972007-12-27T04:57:00.000+10:002007-12-27T04:57:00.000+10:00Thanks Alan. I remember building such a regulator ...Thanks Alan. I remember building such a regulator using 2N3055s when I was young but I think they are NPN.Peter Markshttps://www.blogger.com/profile/13007012724570360389noreply@blogger.comtag:blogger.com,1999:blog-35901825.post-9866453140641446312007-12-27T02:26:00.000+10:002007-12-27T02:26:00.000+10:00You can add a PNP pass transistor to the regulator...You can add a PNP pass transistor to the regulator to boost its current capability. Two resistors are used to set its bypassing point, and current limiting point.<BR/><BR/>The base of the pass transistor is connected to the input of the regulator, the collector to the output, and the emitter through a resistor to the unregulated source. The base/input of the regulator is also connected to the Anonymousnoreply@blogger.com