Post by thread:[EE] 9.5V at 5A

Dave VanHorn wrote: > Anyone have such a regulator that they'd like to part with for cash or ? > I'd prefer a switcher, but a linear will do. > Input is 11-15VDC A linear regulator with 15V in, 9.5V out, and 5A thru it will disspate 27.5W. That's going to require a significant heat sink, probably with forced air cooling. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com

>-----Original Message----- >From: spam_OUTpiclist-bouncesTakeThisOuTmit.edu [.....piclist-bouncesKILLspam@spam@mit.edu] >Sent: 02 June 2005 14:33 >To: Microcontroller discussion list - Public. >Subject: [EE] 9.5V at 5A > > > >Anyone have such a regulator that they'd like to part with for >cash or ? I'd prefer a switcher, but a linear will do. Input >is 11-15VDC LM317T plus external pass transistor? Cheap and cheerfull. Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. =======================================================================

On Thu, Jun 02, 2005 at 03:09:01PM +0100, Michael Rigby-Jones wrote: > > > >-----Original Message----- > >From: piclist-bouncesKILLspammit.edu [.....piclist-bouncesKILLspam.....mit.edu] > >Sent: 02 June 2005 14:33 > >To: Microcontroller discussion list - Public. > >Subject: [EE] 9.5V at 5A > > > > > > > >Anyone have such a regulator that they'd like to part with for > >cash or ? I'd prefer a switcher, but a linear will do. Input > >is 11-15VDC > > LM317T plus external pass transistor? Cheap and cheerfull. Not enough headroom IIRC. With the 0.6V drop from the passtrasistor there would onlyu be 0.9V headroom left at 11V. Not enough. BAJ

{Quote hidden}>-----Original Message----- >From: EraseMEpiclist-bouncesspam_OUTTakeThisOuTmit.edu [piclist-bouncesspam_OUTmit.edu] >Sent: 02 June 2005 15:28 >To: Microcontroller discussion list - Public. >Subject: Re: [EE] 9.5V at 5A > > >On Thu, Jun 02, 2005 at 03:09:01PM +0100, Michael Rigby-Jones wrote: >> >> >> >-----Original Message----- >> >From: @spam@piclist-bouncesKILLspammit.edu [KILLspampiclist-bouncesKILLspammit.edu] >> >Sent: 02 June 2005 14:33 >> >To: Microcontroller discussion list - Public. >> >Subject: [EE] 9.5V at 5A >> > >> > >> > >> >Anyone have such a regulator that they'd like to part with for >> >cash or ? I'd prefer a switcher, but a linear will do. Input >> >is 11-15VDC >> >> LM317T plus external pass transistor? Cheap and cheerfull. > >Not enough headroom IIRC. With the 0.6V drop from the >passtrasistor there would onlyu be 0.9V headroom left at 11V. >Not enough. The pass transistor is a PNP. With the basic configuration shown in the datasheet applications you need a 0.6v drop across the current sense resistor to activate the transistor, but it would be trivial to DC bias the transistor to reduce that to any arbitrary (though temperature dependant) value. Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. =======================================================================

On 6/2/05, Michael Rigby-Jones <RemoveMEMichael.Rigby-JonesTakeThisOuTbookham.com> wrote: {Quote hidden}> > > >-----Original Message----- > >From: spamBeGonepiclist-bouncesspamBeGonemit.edu [TakeThisOuTpiclist-bouncesEraseMEspam_OUTmit.edu] > >Sent: 02 June 2005 15:28 > >To: Microcontroller discussion list - Public. > >Subject: Re: [EE] 9.5V at 5A > > > > > >On Thu, Jun 02, 2005 at 03:09:01PM +0100, Michael Rigby-Jones wrote: > >> > >> > >> >-----Original Message----- > >> >From: RemoveMEpiclist-bouncesTakeThisOuTmit.edu [piclist-bouncesEraseME.....mit.edu] > >> >Sent: 02 June 2005 14:33 > >> >To: Microcontroller discussion list - Public. > >> >Subject: [EE] 9.5V at 5A > >> > > >> > > >> > > >> >Anyone have such a regulator that they'd like to part with for > >> >cash or ? I'd prefer a switcher, but a linear will do. Input > >> >is 11-15VDC > >> > >> LM317T plus external pass transistor? Cheap and cheerfull. > > > >Not enough headroom IIRC. With the 0.6V drop from the > >passtrasistor there would onlyu be 0.9V headroom left at 11V. > >Not enough. > > The pass transistor is a PNP. With the basic configuration shown in the > datasheet applications you need a 0.6v drop across the current sense > resistor to activate the transistor, but it would be trivial to DC bias > the transistor to reduce that to any arbitrary (though temperature > dependant) value. AFAIK with LM317 it can't. 11-9.5V = 1.5V Even the PNP will be ok. It needs a LDO but a linear supply is a wrong option at this current. Vasile {Quote hidden}> Regards > > Mike > > ======================================================================= > This e-mail is intended for the person it is addressed to only. The > information contained in it may be confidential and/or protected by > law. If you are not the intended recipient of this message, you must > not make any use of this information, or copy or show it to any > person. Please contact us immediately to tell us that you have > received this e-mail, and return the original to us. Any use, > forwarding, printing or copying of this message is strictly prohibited. > No part of this message can be considered a request for goods or > services. > ======================================================================= > > -

At 10:34 AM 6/2/2005, PicDude wrote: >On Thursday 02 June 2005 10:03 am, Dave VanHorn scribbled: > > yeah, I could build one, but I was hoping someone had a brick sitting > > on a shelf. > > Too many projects as it is! :) > >IIRC National LM3485 will do this for you. If you use their Webench online >design tool, there is usually an option to buy an assembled eval board >version of the design. Good pick, but no, they aren't doing boards on this device. I'll look a bit and see if they have another that might work though.