Using 100 LM2577/XL6009 to provide 16v @ 200amps from 12v input?

[toysareforboys]

Hello! This is my first time here. I apologize in advance for the long post/questions.

I've built in the trunk of my car a 16.2v maximum capacitor bank (500 farads) and installed two 14v XSPower D1400 batteries (charge at 16v, not connected to anything yet), in addition to the factory battery (it comes in the trunk stock). I wish to run my aftermarket car stereo amplifiers at 16v off the capacitor bank and D1400 batteries but the rest of the car at the stock voltage level off the factory battery/charging system.

My amplifiers draw 230amps total (at 12v ish, not sure if they are any more efficient at 16v).

Because my car (2007 Chevy Cobalt SS/SC) uses an ECU controlled alternator that's impossible to swap without getting a check engine light (not possible to pass emissions check with SES light here) and it's not possible to install a second alternator, my plan to make my 16v dreams come true is:

1. To use 100 of these: **broken link removed**

2. Replace the potentiometer with a fixed resistor (to make sure all the output voltages match perfectly). No idea how to calculate which resistor would get me bang on 16v output. And I need really tight regulation too seeing as my cap bank is maximum 16.2v, but I've read that the regulation on those boards is really good.

3. Attach all 100 of them to a single really nice heatsink.

So, my questions for the more electronically inclined people:

4. Is this the most efficient/cost effective way to provide lots of power to the 16v bank from my stock 12v system?

5. I assume there wouldn't be any issues hooking up 100 of them in parallel, I'd use bus bars for all the input and output power, and the supplier said it's NOT a shared ground system, so that'd be four bus bars.

6. I've read that the LM2577 needs a minimum of a 2v difference between the input and output, so while my car is running at say 14.4v there will be less than a 2v difference to 16v. Not sure if the XL6009 suffers the same problem.

7. How could I effectively attach all 100 of them to a single large aluminum heatsink to cool the main XL6009 chip? Here is what the underneath of the circuit board looks like, no thermal path to cool the back of the XL6009 chip

**broken link removed**

So I assume I'd have to use aluminum square rod to cut a chunk from that would go from the front of the XL6009 to the heatsink to provide the thermal path. They sell these little heatsinks dirt cheap, but not sure that's enough heatsinking for my likes: **broken link removed**

One project I saw they actually cut out the circuit board underneath the XL6009 chip and pushed the chip down so it was flush with the bottom of the circuit board then used a thermal pad and mounted it to a heatsink, looks like it'd work awesome but not sure if there's any traces or anything on that board that might prevent doing that. And to do that to 100 boards would probably get annoying quick.

Any insight you could provide would be greatly appreciated.

-Jamie M.

 

[moffy]

Have a look at: https://www.powerstream.com/dc-12V-16V.htm
If you are only driving your stereo and have 500 Farads(?) of capacitance then you don't need to supply the peak power (200 Amps) but only the continuous power maybe 1/5 to 1/10 of the peak power. What you do have to worry about is blowing fuses or tripping your 16v supply as it tries to charge such a massive capacitance bank. Don't try the 100 modules route it just isn't feasible.

 

[toysareforboys]

Have a look at: http://www.powerstream.com/dc-12V-16V.htm
If you are only driving your stereo and have 500 Farads(?) of capacitance then you don't need to supply the peak power (200 Amps) but only the continuous power maybe 1/5 to 1/10 of the peak power. What you do have to worry about is blowing fuses or tripping your 16v supply as it tries to charge such a massive capacitance bank. Don't try the 100 modules route it just isn't feasible.

Thanks for the super fast reply!

I saw that device. Seems like such a poor value only supplying 17.25 amps for $160USD!? Yikes.

Yep, 500 farads and then some

**broken link removed**
LICK FOR HIGH RES!

6 x 2.7v 3000f caps in series for 500f @ max 16.2v and then the Pyle 3 farad cap (primarily just using it for its awesome 4 x 1/0 gauge power distribution blocks and voltmeter).

I listen to a lot of decaf music so there isn't a lot of time between low notes for the voltage to recover at a slow rate, hence why I was trying to feed as many amps as possible from my 12v system to the 16v system, to help keep it as near 16 volts as I can.

I know what you're saying about the capacitance bank trying to pull MASSIVE amounts of current to recharge itself. You'll notice in the above pic it's unfused. After cooking all of my ANL fuses (even a 500amp one) I just direct connected it and it works much better, lol. It makes my stock alternator glow red because it's under constant maximum load now, instead of just pulses of high current like before. Stereo sounds way better though

Couldn't I put a current draw limiter on each of the 100 modules, like a current limiting diode, but I didn't see any rated for 16v or for 2amps draw That way when the cap bank drops and tries to pull too many amps it will protect the 100 modules.

What exactly would happen to the module if I tried to pull 3 or 4 amps from it? Would the voltage just break down or would it cause damage to the XL6009 or another component? If the entire module assembly tried to pull 200 amps or more from the 12v side I'm sure the voltage would drop to 10v or there abouts, would that help protect the modules at all?

As you can tell I'm really keen on trying out the 100 modules route! lol. If need be I could use 200 or 300 modules, so each of them would only be seeing a fraction of their maximum capacity current draw (when the cap isn't requesting big).

Thanks again for the super fast reply

-Jamie M.

 

[moffy]

Yep, 500 farads and then some

6 x 2.7v 3000f caps in series for 500f @ max 16.2v and then the Pyle 3 farad cap (primarily just using it for its awesome 4 x 1/0 gauge power distribution blocks and voltmeter).
I know what you're saying about the capacitance bank trying to pull MASSIVE amounts of current to recharge itself. You'll notice in the above pic it's unfused. After cooking all of my ANL fuses (even a 500amp one) I just direct connected it and it works much better, lol. It makes my stock alternator glow red because it's under constant maximum load now, instead of just pulses of high current like before. Stereo sounds way better though

You have a very expensive BOMB in your boot. If the caps fail, and they will with your setup, they will explode with considerable force! Putting them in series will not ensure equal voltage sharing! What you are doing is VERY DANGEROUS.

 

[toysareforboys]

You have a very expensive BOMB in your boot. If the caps fail, and they will with your setup, they will explode with considerable force! Putting them in series will not ensure equal voltage sharing! What you are doing is VERY DANGEROUS.

You can see in the picture threaded holes in the joining plates on the caps, that is for the balancing and monitoring system that came with them. I had it connected for a week or so and when I downloaded the data it said it had done almost ZERO balancing, like .01v here, .01v there. So I just left the monitoring sensors connected, not the balancing leads. What I noticed is if I drove around for a long time (say 45 minutes or more) with the stereo OFF (never happens) then the caps would start to slightly get out of balance, the most I saw was around +/- .03v. As soon as I started the car again the big current draw of the starter re-balanced the caps. Even when my car sat unused for 3 days the caps didn't get out of balance at all, and of course any time my stereo even gives a tiny bit of a thump all of the caps go back in balance perfectly. No idea why it works like that or if it'll continue to work like that as the caps age.

Running it now it only sees a maximum of 14.4v (2.4v per cap) so I'm a lot farther away from it's 16.2v maximum rating (2.7 per cap) than I would be with my new 16v setup (2.667v per cap) so I see the potential for disaster is greater. I could add a 7th cap which would give me .414v per cap voltage safety zone if you think that's wise.

-Jamie M.

 

[toysareforboys]

Hey, I found the datasheet for the XL6009! Pretty impressive, it's got over temperature shutdown, over current protection and over voltage protection! Sweet. **broken link removed**

Looks like I might just go the module route after all!

-Jamie M.

 

[tcmtech]

So how are you planning to get 230+ amps from your stock alternator that is only rated for 100 - 120 amps low duty cycle?

Without adequate power at the source to keep the system voltage up there is little point in adding extra load behind it.

 

[toysareforboys]

So how are you planning to get 230+ amps from your stock alternator that is only rated for 100 - 120 amps low duty cycle?

Without adequate power at the source to keep the system voltage up there is little point in adding extra load behind it.

The 200amps at 16v would only be required during a hard audio thump, and the alternator + battery + capacitor bank on the 12v side could supply the more than 230amps to the 100 boards for them to try and keep it at 16v. I`ve ordered some extra cap banks for the 16v side to help out (should have 1285f at 18.9v max). At least that`s my plan

I found a supplier that can offer a 10amp CC/CV 8-14.5v to 16v converters (with super nice linkable heatsinks) for $8 so 20 of those should do nicely. They can be set as high as 12 amps if cooling is sufficient.

I`ve also ordered enough balancing boards to do all my caps even though all banks will have a pretty big margin for error

If it works I`ll be sure to post up pics and vids. I`ll measure the current draw of the amps, converter boards, and how much voltage drop I get on both sides.

-Jamie M.

 

[tcmtech]

Okay.....?

Electrically none of any of this make any justifiable sense.

Given the rough specs of what you have now the 500 F capacitor bank should be capable of at least 1000+ amps and the two D1400 batteries should be good for another 2400 amps per their online specs. Given that you have about 30X more peak burst capacity (~93,000 watts) on tap than your amplifiers theoretical peak power draw (Guessing it's a C2 Audio 2.4 with a peak capacity of ~3100 watts mono @ 1 ohm) is capable of taking.

Now you want to add an overly complicated voltage boost converter to bring additional power from your stock alternator that realistically has maybe 50 amps (~700 watts) at best of peak usable power to supply above and beyond your typical automotive power requirements.

The costs, rational and reasoning behind the power supply system seems pretty poorly thought out from an engineering standpoint give the online pricing for the present components could have easily bought you a second C2 Audio 2.4 amplifier and 12V deep cycle battery giving you far more audio power to work with with way less needles components.

BTW years ago I used to design custom car audio power and amplifier systems so I have some clue as to what gives the most boom for the bucks spent and what you have ain't it.

 

[audioguru]

I cannot believe having a sound system in a car that uses 230A at 12V (2760W) where the amplifiers are probably class-D for high efficiency so they do not melt the car. The power feeding the speakers is probably 2200W.
I also had a Chevy Cobalt but it came with the upgraded Pioneer sound system. It had speakers all over the car and a 10" sub-woofer in the trunk (boot?). Its amplifiers produced a total power of 277W and it was able to be VERY loud with low distortion. The amplifiers were linear, not class-D so they produced about 100W of heat when the amplifiers were blasting max power continuously.

 

[MrAl]

Hello,

Buy two quality hearing aids if the music isnt loud enough for you, then use a regular stereo. What makes you think other people will want to listen to the music you like when you're driving down the road? What do you think you are, a baseball stadium

Seriously, if you need that much amplifier power in your car stereo something is wrong and it's not with the electronics.

 

[audioguru]

What makes you think other people will want to listen to the music you like when you're driving down the road?

We hear him coming before seeing that his car has blacked out windows and is so low that it scrapes on the ground producing sparks.
He needs all that amplifier power because the car engine has its mufflers removed (it probably also has its pollution controls removed).

 

[tcmtech]

Seriously, if you need that much amplifier power in your car stereo something is wrong and it's not with the electronics.

I take it you have forgotten your annoying things you did as a rebellious teen back in the late 1800's? Like riding your horse too fast shooting perfectly good bullets into the air just to make noise and chasing loose women who wore dresses that were too short that showed leg above the ankle what not?

Back in the 90's I was one of those kids with the huge sound system and I can assure you that at that age it's a perfectly justified thing to own and to be honest its a way better hobby to have than going out getting drunk of high and doing stupid stuff like far too many kids do instead.

 

[alec_t]

It makes my stock alternator glow red because it's under constant maximum load now

You're planning a pyrotechnics display to accompany the din from the stereo system?

 

[MrAl]

I take it you have forgotten your annoying things you did as a rebellious teen back in the late 1800's? Like riding your horse too fast shooting perfectly good bullets into the air just to make noise and chasing loose women who wore dresses that were too short that showed leg above the ankle what not?

Back in the 90's I was one of those kids with the huge sound system and I can assure you that at that age it's a perfectly justified thing to own and to be honest its a way better hobby to have than going out getting drunk of high and doing stupid stuff like far too many kids do instead.

Hi,

Now hold on there a minute pilgrim...i may be olden but im still not deaf (ha ha).

I have to agree i would rather see kids get involved with technology rather than drugs or alcohol, but unfortunately one does not preclude the other, unless they themselves would have it that way.

But to get a little more serious, i think 200 amps is too much current to draw from the system. Even 100 amps would be pushing it. 100 amps is 1200 watts at 12 volts, and that's some serious heating power. I have to wonder if something isnt going to blow, and what kind of fuse would be used for that 200 amps.

I am not up on my high end car stereo systems either though, so i dont know what the current commercial units do or dont do. Perhaps someone else here knows, and can quote some specs. We should take a look at what is already being done out there.

I cant help but wonder about why someone would want 1200 watts in a speaker that is 3 to 5 feet away from their ears. Maybe a couple hundred watts, but 1200 to 2400 watts is a lot of sound power. That's like trying to make a radio station that transmits audio rather than RF <chuckle>.

But again looking at the more serious side, the psychophysical effect of high sound pressures on the human brain function would have to be investigated. Some sounds could delay the brain response similar to alcohol, while some could even force the eyes to close for unusually long times. Any of these effects would actually be very dangerous not only to the driver and passengers of the so equipped car but also others.

 

[ronsimpson]

I have dumped 1000s of watts into a auditorium. Putting 1000s of watts into a 5 foot x 5 foot car seem wrong. I have seen paint on a car door crack because of too much audio power.

If I wanted to make a loud car; I would boost the 12V to 24 and then build a bridge power amp. A forward 2X voltage doubler is simple.

Simple answer: make a 250 watt head phone.

 

[tcmtech]

Actually with the high wattage car audio systems almost all the power is going into the low bass notes which our bodies tend to handle just fine.

I was one of kids with the huge sound system in a small car and to this day I still have above average hearing so I can attest to the fact that not all kids go deaf from loud music.

Now as questions go about low voltage high current a few hundred amps at 12 volts is not a strange poorly understood science. Its pretty basic electrical principles to be honest.
High current fuses with large gauge wire are used just the same as would be used in any common power inverter system which we all know making those in the 12 volt and 3000 - 5000 watt continuous duty application is obviously doable so a few hundred amps in short peaks for a audio system is no big deal.

Now as far as the amplifiers and their input voltage goes most any that are rated for over a few tens of watts will have a SMPS system that takes the 12 volt power and steps it up to whatever the amplifier need for its rail voltage which in many large KW+ units maybe plus and minus 40 - 100 VDC rail voltages.

Given that they are running SMPS giving them voltages over their rated 14.4 VDC input to get more power out is like taking a common universal voltage SMPS that rated for 100 - 250 VAC input and changing it from a 120 VAC power feed to a 240 VAC power feed and expecting that the regulated output voltage and power capacity will improve.

The only way adding extra voltage above and beyond a car audio amplifiers rated inputs is going to help is if its experiencing severe undervoltage issues due to poor and or undersized wiring or limited source power.

In the case of the OP's system if he is running power cabling of at least 0 ga copper and at least one of his system batteries is good pulling several hundred amps of current for any length of time and having the amplifiers input voltages stay above their 10 volt minimum input requirement should not be a problem unless these are some really over rated and poorly built units with really crappy power supply systems.

Ideally if it was me for added peak voltage support I would have the super cap bank wired in as close to the amplifier's main power input as possible to compensate for any degree of supply voltage drop due to line or connection resistances.

Lastly if the OP is a audiophile all rational logical reasoning and measurable effects are null and void so all of my opinions can be ignored.

 

[audioguru]

Look at the size, weight and power rating for this car speaker:

 

[MrAl]

Hi,

audioguru:
Wow, that's amazing.

tcmtech:
I can tell by your response that you have not read any government studies on the effects of low frequency sound on humans. Problems include attention disorder and lessening of the ability to concentrate. That's not even getting into the super loud category yet. Super loud sound can seriously disorient a person where they might even feel like they are falling. Remember the inner ear controls balance, and the ear is just ONE part of the body that perceives sound.
Read up on this a bit more and you'll see what goes on here.

 

[tcmtech]

Why would I care to want to read about stuff like that and given it government funded if anything I am obligated from past experience to to believe that it's likely either not true or at least heavily biased to support some ill conceived government power grab.

If it's too loud you're too old and if you think the government needs to be involved .....

Kids will be kids and teens will be teens just like how we were once. Young, dumb, careless and near indestructible by our own reasoning. It's the only way to get the scars that will be worth showing off later in life.