Yzordderrex <powersupplyguy@netzero.net> wrote in news:1b7567ab-9638-45dd-8366-872c961e58e6@googlegroups.com:> Greetings, > > I have a small diesel engine spinning a DC generator. I need a > control chip that will take approximately 60v that generator puts out > and charge the lead acid bank. Bank is 16 27M Die Hard deep cycle > wired in 4x4 configuration. It is my intention to control diesel > speed to give me a little headroom for charging the battery pack. I > will use external mosfets to get about 50A of charging current, so > just looking for the control chip. > > Any ideas would be helpful. > > thanks, > Bob > N9NEO >Why not regulate the generator to output the correct charge voltage? No conversion losses, only slight modifications to the generator control hardware.
Re: Need PWM controller for current source to charge 48v lead acid.
Started by ●December 19, 2012
Reply by ●December 19, 20122012-12-19
Greetings, I have a small diesel engine spinning a DC generator. I need a control chi= p that will take approximately 60v that generator puts out and charge the l= ead acid bank. Bank is 16 27M Die Hard deep cycle wired in 4x4 configurati= on. It is my intention to control diesel speed to give me a little headroo= m for charging the battery pack. I will use external mosfets to get about = 50A of charging current, so just looking for the control chip. Any ideas would be helpful. thanks, Bob N9NEO
Reply by ●December 20, 20122012-12-20
Sjouke Burry wrote:> > Yzordderrex ?powersupplyguy@netzero.net? wrote in > news:1b7567ab-9638-45dd-8366-872c961e58e6@googlegroups.com: > > ? Greetings, > ? > ? I have a small diesel engine spinning a DC generator. I need a > ? control chip that will take approximately 60v that generator puts out > ? and charge the lead acid bank. Bank is 16 27M Die Hard deep cycle > ? wired in 4x4 configuration. It is my intention to control diesel > ? speed to give me a little headroom for charging the battery pack. I > ? will use external mosfets to get about 50A of charging current, so > ? just looking for the control chip. > ? > ? Any ideas would be helpful. > ? > ? thanks, > ? Bob > ? N9NEO > ? > > Why not regulate the generator to output the correct charge voltage? > No conversion losses, only slight modifications to the > generator control hardware.or a switching regulator, so the engine can run at its most efficient speed?
Reply by ●December 20, 20122012-12-20
On 12/19/2012 6:52 PM, Yzordderrex wrote:> Greetings, > > I have a small diesel engine spinning a DC generator. I need a control chip that will take approximately 60vthat generator puts out and charge the lead acid bank. Bank is 16 27M Die Hard deep cycle wired in 4x4 configuration. It is my intention to control diesel speed to give me a little headroom for charging the battery pack. I will use external mosfets to get about 50A of charging current, so just looking for the control chip.> > Any ideas would be helpful. > > thanks, > Bob > N9NEOWhat's the fully charged voltage of your battery? Looks like you have barely enough voltage. Crank the engine speed down 5%. And regulate it by current and voltage. Probably less lossy than the best switcher you can build that will run off that little headroom. High technology is not always the best answer. You want to run the engine at maximum efficiency whatever the charge level. That may not be the same speed over the whole charging range. And it only takes 10 milliohms of cable to lose half a volt.
Reply by ●December 20, 20122012-12-20
On Thu, 20 Dec 2012 00:57:33 -0500, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:> >Sjouke Burry wrote: >> >> Yzordderrex ?powersupplyguy@netzero.net? wrote in >> news:1b7567ab-9638-45dd-8366-872c961e58e6@googlegroups.com: >> >> ? Greetings, >> ? >> ? I have a small diesel engine spinning a DC generator. I need a >> ? control chip that will take approximately 60v that generator puts out >> ? and charge the lead acid bank. Bank is 16 27M Die Hard deep cycle >> ? wired in 4x4 configuration. It is my intention to control diesel >> ? speed to give me a little headroom for charging the battery pack. I >> ? will use external mosfets to get about 50A of charging current, so >> ? just looking for the control chip. >> ? >> ? Any ideas would be helpful. >> ? >> ? thanks, >> ? Bob >> ? N9NEO >> ? >> >> Why not regulate the generator to output the correct charge voltage? >> No conversion losses, only slight modifications to the >> generator control hardware. > > > or a switching regulator, so the engine can run at its most efficient >speed?Gee, that's a GREAT idea. Maybe you should tell the car manufacturers about that. ;-)
Reply by ●December 20, 20122012-12-20
krw@att.bizzz wrote:> > Michael A. Terrell wrote: > > > >Sjouke Burry wrote: > >> > >> Why not regulate the generator to output the correct charge voltage? > >> No conversion losses, only slight modifications to the > >> generator control hardware. > > > > Or a switching regulator, so the engine can run at its most efficient > >speed? > > Gee, that's a GREAT idea. Maybe you should tell the car manufacturers > about that. ;-)Do you think the UAW would let them do anything to improve a vehicle if they can't pad the production line with more of their people? For instance: Back in the '70s Delco designed a car radio that could be installed from the front of the dash with no tools. The UAW threw a hissy fit, because it would cost a few union jobs. At one time there were variable rate automatic transmissions which did optimize the power curve but I haven't heard of one in decades.
Reply by ●December 20, 20122012-12-20
mike <ham789@netzero.net> wrote:>On 12/19/2012 6:52 PM, Yzordderrex wrote: >> Greetings, >> >> I have a small diesel engine spinning a DC generator. I need a control chip that will take approximately 60v > >that generator puts out and charge the lead acid bank. Bank is 16 27M >Die Hard deep cycle wired in 4x4 configuration. > >It is my intention to control diesel speed to give me a little headroom >for charging the battery pack.I'd use a microcontroller. That puts everything under one software controlled loop. In that case it's also easy to have the diesel start and stop automatically.>I will use external mosfets to get about 50A of charging current, so >just looking for the control chip. >> >> Any ideas would be helpful. >> >> thanks, >> Bob >> N9NEO >What's the fully charged voltage of your battery? >Looks like you have barely enough voltage. >Crank the engine speed down 5%. And regulate it by current >and voltage. Probably less lossy than the best switcher >you can build that will run off that little headroom. >High technology is not always the best answer. > >You want to run the engine at maximum efficiency whatever >the charge level. That may not be the same speed over >the whole charging range.Running a diesel at maximum effiency is at near full power (or at least near maximum torque). So a switcher if most likely to provide the best fuel economy. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Reply by ●December 20, 20122012-12-20
On Wed, 19 Dec 2012 18:52:53 -0800 (PST), Yzordderrex <powersupplyguy@netzero.net> wrote:>Greetings, > >I have a small diesel engine spinning a DC generator. I need a control chip that will take approximately 60v that generator puts out and charge the lead acid bank. Bank is 16 27M Die Hard deep cycle wired in 4x4 configuration. It is my intention to control diesel speed to give me a little headroom for charging the battery pack. I will use external mosfets to get about 50A of charging current, so just looking for the control chip. > >Any ideas would be helpful. > >thanks, >Bob >N9NEOWhat kind of generator is it? Does the generator have a controllable field winding? Field control would be easier than brute-force regulating the high power output. Alternator+rectifier types can be regulated by shorting their outputs, often with an SCR. Shorting such a generator with PWM'd mosfets would be interesting. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Reply by ●December 20, 20122012-12-20
On Wed, 19 Dec 2012 18:52:53 -0800, Yzordderrex wrote:> Greetings, > > I have a small diesel engine spinning a DC generator. I need a control > chip that will take approximately 60v that generator puts out and charge > the lead acid bank. Bank is 16 27M Die Hard deep cycle wired in 4x4 > configuration. It is my intention to control diesel speed to give me a > little headroom for charging the battery pack. I will use external > mosfets to get about 50A of charging current, so just looking for the > control chip. > > Any ideas would be helpful.To answer your actual question: just about anything that calls itself a PWM controller can be used. No matter what you'll need to build the gate driver circuit and final switching circuit yourself, and that's where the challenge is. I'm almost tempted to say that if you have to ask you shouldn't do it -- but instead I'll just say that you should plan on burning up a few boards... The LM3524 and TL494 are classics. Someone suggested a microprocessor with a PWM output -- I'd be very tempted to go that route, myself. Do keep in mind that for charging lead-acid batteries you want to implement a current-limited constant-voltage supply -- lead-acid batteries do _not_ like being charged at too high a voltage. The ideal charger would monitor the battery temperature and adjust that final charge voltage, to boot. Also keep in mind that you may want to implement some balancing within your series string: because you don't want to bring the battery voltage too high, you want to avoid a circumstance where you have some parallel banks at low voltage, and one or more at a too-high voltage. (I don't know where balancing becomes important with lead-acid batteries, but I'm pretty sure that when you have 24 cells in a string it means something). I'd be tempted to charge the batteries as four series strings, with four individual chargers (with balancing). This should cost less than 4x as much, because your switches and inductors will get cheaper as their current capability goes down. What you do is up to you, of course. -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
Reply by ●December 20, 20122012-12-20
On Thursday, December 20, 2012 7:39:33 AM UTC-8, Michael Terrell wrote:> krw@att.bizzz wrote: > > > > > > Michael A. Terrell wrote: > > > > > > > >Sjouke Burry wrote: > > > >> > > > >> Why not regulate the generator to output the correct charge voltage? > > > >> No conversion losses, only slight modifications to the > > > >> generator control hardware. > > > > > > > > Or a switching regulator, so the engine can run at its most efficient > > > >speed? > > > > > > Gee, that's a GREAT idea. Maybe you should tell the car manufacturers > > > about that. ;-) > > > > > > Do you think the UAW would let them do anything to improve a vehicle > > if they can't pad the production line with more of their people? > > For instance: Back in the '70s Delco designed a car radio that could be > > installed from the front of the dash with no tools. The UAW threw a > > hissy fit, because it would cost a few union jobs. >But can it be removed with no tools? If so, I would throw a fit as well. It would be open invitation for car thieves and broken windows.