On Wednesday, November 2, 2022 at 11:05:32 AM UTC-4, John Larkin wrote:> On Wed, 2 Nov 2022 05:07:36 -0700 (PDT), Fred Bloggs > <bloggs.fred...@gmail.com> wrote: > > >On Wednesday, November 2, 2022 at 8:03:56 AM UTC-4, legg wrote: > >> On Wed, 2 Nov 2022 04:16:41 -0700 (PDT), Fred Bloggs > >> <bloggs.fred...@gmail.com> wrote: > >> > >> >On Wednesday, November 2, 2022 at 5:39:41 AM UTC-4, Don Y wrote: > >> >> The "charge" functions are pretty easily understood. > >> >> > >> >> But, is the "engine start" function just a whopping big > >> >> transformer-rectifier-filter sitting behind the clamps? > >> >> > >> >> I'm speaking of the ~200A load current devices, not > >> >> the smaller 50A; something along the lines of: > >> >> <https://dygtyjqp7pi0m.cloudfront.net/i/40360/34822921_1m.jpg> > >> > > >> >Lead acid charger/ starters don't need or use a filter. The battery is a natural filter. When energy is applied at 60-120 Hz, it looks like the DC average to the battery, which doesn't respond to those frequencies. If the charger/ starter is built into a wheeled cart and is heavy, that's a clue it's based on a line powered stepdown transformer. From what I can see from the few diagrams available, they all use a center tapped transformer, tap is common ( from there to battery NEG clamp) and the hot legs go to individual high current diodes (anodes), the cathodes are connected together to provide current to the battery POS clamp. Depending on diode packaging that orientation could be reversed for heat sinking purposes- as with interference fitted stud packages. They can add stuff in POS clamp lead like current limiting resistor and circuit breaker and maybe other things like an over-duty timer in starter mode for idiot proofing. The center tapped xformer makes sense by minimizing > >> >number of expensive high current semiconductors required, reducing voltage loss, and minimizing the iron stack required. > >> >Interestingly DieHard was ( at least at one time) manufactured by Schumacher, one of the best available. > >> > > >> >The question is do Americans pronounce Schumacher as: > >> > > >> >1: SHOO- MACH-ER > >> >or > >> >2:SHOO-MAH-SHER > >> Shoemaker, unless you're in Europe. > >> > >> RL > > > >Thanks - was wondering. Ever since I heard a French national use pronunciation #2 I haven't been able to shake it. > Lots of cool occupation names: > > Shepherd > Baker > Plumber/plummer > Weaver > Mason > Bailey > Fletcher > Carpenter > Fisher > > I think Larkin means groundskeeper or steward. > > Bloggs?They think it meant bookbinder. They have a family crest with what looks like some of those hunting hawks and a tree stump with something or another stuck in it. https://www.houseofnames.com/bloggs-family-crest#:~:text=The%20origins%20of%20the%20Bloggs,as%20a%20shoemaker%20or%20bookbinder.
Lead-acid charger/starter
Started by ●November 2, 2022
Reply by ●November 2, 20222022-11-02
Reply by ●November 2, 20222022-11-02
On Wednesday, November 2, 2022 at 2:42:08 PM UTC-4, Don Y wrote:> On 11/2/2022 4:16 AM, Fred Bloggs wrote: > > On Wednesday, November 2, 2022 at 5:39:41 AM UTC-4, Don Y wrote: > >> The "charge" functions are pretty easily understood. > >> > >> But, is the "engine start" function just a whopping big > >> transformer-rectifier-filter sitting behind the clamps? > >> > >> I'm speaking of the ~200A load current devices, not the smaller 50A; > >> something along the lines of: > >> <https://dygtyjqp7pi0m.cloudfront.net/i/40360/34822921_1m.jpg> > > > > Lead acid charger/ starters don't need or use a filter. The battery is a > > natural filter. When energy is applied at 60-120 Hz, it looks like the DC > > average to the battery, which doesn't respond to those frequencies. If the > > charger/ starter is built into a wheeled cart and is heavy, that's a clue > > it's based on a line powered stepdown transformer. From what I can see from > > the few diagrams available, they all use a center tapped transformer, tap is > > common ( from there to battery NEG clamp) and the hot legs go to individual > > high current diodes (anodes), the cathodes are connected together to provide > > current to the battery POS clamp. Depending on diode packaging that > > orientation could be reversed for heat sinking purposes- as with > > interference fitted stud packages. They can add stuff in POS clamp lead like > > current limiting resistor and circuit breaker and maybe other things like an > > over-duty timer in starter mode for idiot proofing. The center tapped > > xformer makes sense by minimizing number of expensive high current > > semiconductors required, reducing voltage loss, and minimizing the iron > > stack required. Interestingly DieHard was ( at least at one time) > > manufactured by Schumacher, one of the best available. > That's how they WERE designed -- 60 years ago. > > But, back then, there were no "electronics" that had to continue > operating with the "battery" dropping to 0V between "cycles". > Rather, the "electrics" just had to tolerate battery dropping to > ~6V -- and the starter relay continuing to "hold". > > With a completely flat (or removed/disconnected) battery, the > "charger/starter" is the sole source of current. > > Would they design ECUs with the ability to carryover when powered > by rectified AC? Or, would they just have enough bulk decoupling > to even out the *DC* that they expect on their inputs?I doubt it. The SAE requirement last I looked was everything operate down to 8V - to get through starting.> > [I'm actually looking at 24V starters] > > The question is do Americans pronounce Schumacher as: > > > > 1: SHOO- MACH-ER or 2:SHOO-MAH-SHER > smith
Reply by ●November 3, 20222022-11-03
On 11/2/2022 6:31 PM, Fred Bloggs wrote:> On Wednesday, November 2, 2022 at 2:42:08 PM UTC-4, Don Y wrote: >> On 11/2/2022 4:16 AM, Fred Bloggs wrote: >>> On Wednesday, November 2, 2022 at 5:39:41 AM UTC-4, Don Y wrote: >>>> The "charge" functions are pretty easily understood. >>>> >>>> But, is the "engine start" function just a whopping big >>>> transformer-rectifier-filter sitting behind the clamps? >>>> >>>> I'm speaking of the ~200A load current devices, not the smaller 50A; >>>> something along the lines of: >>>> <https://dygtyjqp7pi0m.cloudfront.net/i/40360/34822921_1m.jpg> >>> >>> Lead acid charger/ starters don't need or use a filter. The battery is a >>> natural filter. When energy is applied at 60-120 Hz, it looks like the DC >>> average to the battery, which doesn't respond to those frequencies. If the >>> charger/ starter is built into a wheeled cart and is heavy, that's a clue >>> it's based on a line powered stepdown transformer. From what I can see from >>> the few diagrams available, they all use a center tapped transformer, tap is >>> common ( from there to battery NEG clamp) and the hot legs go to individual >>> high current diodes (anodes), the cathodes are connected together to provide >>> current to the battery POS clamp. Depending on diode packaging that >>> orientation could be reversed for heat sinking purposes- as with >>> interference fitted stud packages. They can add stuff in POS clamp lead like >>> current limiting resistor and circuit breaker and maybe other things like an >>> over-duty timer in starter mode for idiot proofing. The center tapped >>> xformer makes sense by minimizing number of expensive high current >>> semiconductors required, reducing voltage loss, and minimizing the iron >>> stack required. Interestingly DieHard was ( at least at one time) >>> manufactured by Schumacher, one of the best available. >> That's how they WERE designed -- 60 years ago. >> >> But, back then, there were no "electronics" that had to continue >> operating with the "battery" dropping to 0V between "cycles". >> Rather, the "electrics" just had to tolerate battery dropping to >> ~6V -- and the starter relay continuing to "hold". >> >> With a completely flat (or removed/disconnected) battery, the >> "charger/starter" is the sole source of current. >> >> Would they design ECUs with the ability to carryover when powered >> by rectified AC? Or, would they just have enough bulk decoupling >> to even out the *DC* that they expect on their inputs? > > I doubt it. The SAE requirement last I looked was everything operate down to 8V - to get through starting.So, you'd not *expect* "rectified AC" on your "DC In" pin. Rather, you'd expect the battery to provide a floor of at least 8V with the "ripple" appearing above that.
