My Tail Lights Must Be Invisible...

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Posted by: neomr2

I am not sure what voltage stiffening issue is in the context you are using it.  

The battery has an internal resistance that is a function of charge where fully charged = very low resistance and partially discharged =  increased resistance.

The cabling also has resistance, so when the lights come on a voltage is dropped across the battery's internal resistance (which reduces the terminal voltage), voltage is dropped across the cabling, and voltage is dropped across the load.

Kirchhoff's voltage law states the sum of these voltage drops must equal the battery's open circuit, or steady state voltage.

Most of the audio guys I know use a very large capacitor across the amplifier's input voltage/ground terminals - this keeps the voltage stiff or close to constant at this node pair.

Yes, lithium batteries do have a much lower internal resistance when fully charged as well as a higher efficiency so it is a definite energy upgrade.

In the context of having a stiff power supply that is mostly resistant to current swings or fluctuations  at the source due to the quick demands of an electrical load on the system.  In the old days you could essentially run the car with just the alternator but with modern cars they need a battery to filter out the fluctuations otherwise you can damage electronic components that modern cars rely on.  

There will always be a drop but the purpose of having a stiff electrical system is to eliminate wide fluctuations by  wiring with shorter runs, by increasing the gauge or in this case using devices that are more effecient.  It also calls upon the source having less internal resistance which would be the battery that can deteriorate in time  especially with those that run light weight batteries that have much lower capacity that will quickly increase its internal resistance to where it will be evident. 

The battery in line with the alternator is necessary to keep the voltage stiff so it can meet the demands of the cars electrical system quickly where the alternators voltage regulator would need to catch up.  Keeping a good power supply even when using a normal sized battery is also essential for battery and alternator life but more so for the electrical as power fluctuations are not desirable for electronics which can shorten its life. 

 The use of large capacitors sold  for car audio  systems is not what it appears to be especially for the advertising. It was thought that these capacitors can recharge quick enough and disperse  enough energy to meet the demands of the amps that drive the subs. What they uncovered was they were a bandaid in that they can be used for a transient passages but what ends up happening is the power source gets depleted very quickly and the subs will have no advantage.  People think they work because it stops the headlights from fluctuating with the beat of the music  but what is actually doing is dimming the lights and acting like a filtering capacitor.  Those that use to compete in car audio past were upgrading both the alternator, battery or both and trying to find amps with unregulated power supplies.   These days the use of capacitors, batteries or bigger alternators are almost nearly eliminated with the advent of class D amplification where it is far more efficient than the previous class A/B.  

Posted by: NottaMiata

 

Edit: after re-reading that article, I see that the brake lights are said to be equal brightness to incandescent, but faster response, and only the 3rd light is brighter with the LEDs. So the 3rd light is where I will start, and try to find brighter tail light bubs if possible. I really want a bit more candlepower there too. These people are scaring the crap out of me; it's really gotten quite bad lately.

 It could be that my old brake like bulbs were tired but there was a significant difference in brightness that was evident.   

In regard to the instant on nature of  LEDs its also evident. When you step on the brakes with the filament bulbs you can actually see them starting off dim and brightening up.  

They did an industry academic study on the LED brake lights and found that its instant brightness effects the other drivers  reaction time does have an effect on vehicle safety by reducing the braking distance of the other driver. 

Posted by: Dev

In the context of having a stiff power supply that is mostly resistant to current swings or fluctuations  at the source due to the quick demands of an electrical load on the system.  In the old days you could essentially run the car with just the alternator but with modern cars they need a battery to filter out the fluctuations otherwise you can damage electronic components that modern cars rely on.  

There will always be a drop but the purpose of having a stiff electrical system is to eliminate wide fluctuations by  wiring with shorter runs, by increasing the gauge or in this case using devices that are more effecient.  It also calls upon the source having less internal resistance which would be the battery that can deteriorate in time  especially with those that run light weight batteries that have much lower capacity that will quickly increase its internal resistance to where it will be evident. 

The battery in line with the alternator is necessary to keep the voltage stiff so it can meet the demands of the cars electrical system quickly where the alternators voltage regulator would need to catch up.  Keeping a good power supply even when using a normal sized battery is also essential for battery and alternator life but more so for the electrical as power fluctuations are not desirable for electronics which can shorten its life. 

 The use of large capacitors sold  for car audio  systems is not what it appears to be especially for the advertising. It was thought that these capacitors can recharge quick enough and disperse  enough energy to meet the demands of the amps that drive the subs. What they uncovered was they were a bandaid in that they can be used for a transient passages but what ends up happening is the power source gets depleted very quickly and the subs will have no advantage.  People think they work because it stops the headlights from fluctuating with the beat of the music  but what is actually doing is dimming the lights and acting like a filtering capacitor.  Those that use to compete in car audio past were upgrading both the alternator, battery or both and trying to find amps with unregulated power supplies.   These days the use of capacitors, batteries or bigger alternators are almost nearly eliminated with the advent of class D amplification where it is far more efficient than the previous class A/B.  

In the context of a stiff voltage at the terminal end, even a tightly regulated supply cannot do this if there are significant voltage drops around a closed loop. 

The only way to fix this is to reduce the larger voltage drops around the loop of interest.

One way to do this is to increase the wire diameter between points and/or add an energy storage device at the terminal end to supply impulse current to the load.

The best device for storing and delivering impulse currents to the load is a large Farad value capacitor or another battery at the load - this reduces the voltage drop across the wiring during the large peak, short duration, current demand.

As for audio amplifiers, class "D" is more efficient, but also generates much more distortion due to only amplifying part of the input sinusoidal signal while being in cut-off during the rest of the signal...

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Posted by: neomr2

Posted by: Dev

In the context of having a stiff power supply that is mostly resistant to current swings or fluctuations  at the source due to the quick demands of an electrical load on the system.  In the old days you could essentially run the car with just the alternator but with modern cars they need a battery to filter out the fluctuations otherwise you can damage electronic components that modern cars rely on.  

There will always be a drop but the purpose of having a stiff electrical system is to eliminate wide fluctuations by  wiring with shorter runs, by increasing the gauge or in this case using devices that are more effecient.  It also calls upon the source having less internal resistance which would be the battery that can deteriorate in time  especially with those that run light weight batteries that have much lower capacity that will quickly increase its internal resistance to where it will be evident. 

The battery in line with the alternator is necessary to keep the voltage stiff so it can meet the demands of the cars electrical system quickly where the alternators voltage regulator would need to catch up.  Keeping a good power supply even when using a normal sized battery is also essential for battery and alternator life but more so for the electrical as power fluctuations are not desirable for electronics which can shorten its life. 

 The use of large capacitors sold  for car audio  systems is not what it appears to be especially for the advertising. It was thought that these capacitors can recharge quick enough and disperse  enough energy to meet the demands of the amps that drive the subs. What they uncovered was they were a bandaid in that they can be used for a transient passages but what ends up happening is the power source gets depleted very quickly and the subs will have no advantage.  People think they work because it stops the headlights from fluctuating with the beat of the music  but what is actually doing is dimming the lights and acting like a filtering capacitor.  Those that use to compete in car audio past were upgrading both the alternator, battery or both and trying to find amps with unregulated power supplies.   These days the use of capacitors, batteries or bigger alternators are almost nearly eliminated with the advent of class D amplification where it is far more efficient than the previous class A/B.  

In the context of a stiff voltage at the terminal end, even a tightly regulated supply cannot do this if there are significant voltage drops around a closed loop. 

The only way to fix this is to reduce the larger voltage drops around the loop of interest.

One way to do this is to increase the wire diameter between points and/or add an energy storage device at the terminal end to supply impulse current to the load.

The best device for storing and delivering impulse currents to the load is a large Farad value capacitor or another battery at the load - this reduces the voltage drop across the wiring during the large peak, short duration, current demand.

As for audio amplifiers, class "D" is more efficient, but also generates much more distortion due to only amplifying part of the input sinusoidal signal while being in cut-off during the rest of the signal...

 

  Yes and no. having the caps near the source is how its done  but having it be beneficial for the demands of how most people set up their car audio requires a much larger capacity that 1 farad cant for long and in most cases the problems were always the source being anemic for the overall power demands of the system. If playing classical music maybe for the transients but for bass heads it gets exhausted.  

 In regards to class D amplification it is true that the first iterations were not clean  but that did not matter because for subwoofers the distortion was negligible for its purpose of spacial competition which increases their popularity and is now the norm.   

About ten or 15 years ago they have perfected class D amplification so much so they can nearly go head to head with class A/B amplification and actually exceed the run of the mill stuff. 

Actually the amp that I use is a class  Gh amp that only weighs about 3lbs but can produce 90x4 RMS. It also  produces better sound quality stats than most class A/B amps that weigh three or four times as much and because its micro controlled it can save its self from failing.  It runs very cool and is extremely efficient. 

 Most home theater high end  subwoofers are now class D amplification because they can pack a large punch in a small package and keep it reliable. These subs were made for sound quality and they don't come up short compared to any advantages A/B would have and they are far more economical to make. 

So I have a few comments here to make. Bear with me.

First, thank you for the love! Glad I come to mind when people think "who do I ask about a topic that's so silly only Halo would love it?"

Second, let me be clear. DOT regulations are important. But in this case... screw following DOT regulation. Not much brightness needs to be added to make our taillights illegal. The problem is that our brake lights are somewhat small, and our third brake light uses measly 194 bulbs. Meant for city lights and corner lights. Good optics behind them, but more is necessary. For such an invisible car, I'm willing to add a little glare and dazzle to my brake lights to be seen. Not too much, let's use common sense. But some 

Third, let's talk about what makes brake lights good. 1. Size. We're at a disadvantage. 2. Position, we're at a MAJOR disadvantage. 3. Brightness, we can obviously improve this. 4. Instant on, LED really does help. Watch the video below. That's my Corolla, left has new LEDs (equal in brightness to stock, NOT an upgrade in brightness) and right has the old worn out incandescents. 5. Flashers for the third brake light. If they're not constant flash, let's say 3 flashes, I think it's a great idea. I'd do it to my own car too! Even more effective with LEDs. 

Last, let's start with the recommendations! My LED thread on Spyderchat is woefully outdated, LED tech moves FAST and the Haloruler64 is busy and lazy. OP you seem to want some serious power behind your brake lights. I have the perfect suggestion. JDM ASTAR stopped making the 194 red LEDs I used on Amazon. These seem identical. https://amzn.to/2S4X8mj If you want straight from the source, here: https://www.jdmastar.com/product/247/3014-SMD-194-168-175-2825-LED-Bulbs-Set-of-2.html but do keep in mind JDM ASTAR doesn't make LEDs, they only rebrand. These VLEDs are pricey, but they work great too. https://www.vleds.com/shop-bulb-numbers/194-168-158-led/194-26-hpc.html

Brake lights? Let's get some serious power behind them. The VLEDs 50 LED bulbs are AWESOME, super bright. Yeah you'll need four, so $120, so they don't come cheap. Low brightness. is pretty bright, but high for brakes is way brighter than stock. And the beam pattern is quite good, very usable. All my photos in every review I did are gone thanks to Dropbox (purely malicious move on their part) so my reviews are not worthless... but they're worth less. But I did review this bulb, and it's badass. And the color is this lovely DEEP MAROON RED, not the red/orange of most other bulbs. https://www.vleds.com/shop-bulb-numbers/7443/7443-50-r.html

No I don't consider them too bright. In person they're very usable. Sadly I only have one, that they sent for review, so I'm running one haha. 

If you want to go all out, VLEDs Triton V6 is the way to go. They're stupid bright, and have a virtual filament to emulate an incandescent bulb. Beefy, but awesome. And VERY expensive. I have the old V3s in my Lexus front turn signals. The V6 Extremes... I think they're simply too bright. https://www.vleds.com/shop-bulb-numbers/7443/v6-triton-kit-r-7443.html

Do let me know if you really need less expensive recommendations. A lot of the LEDs I've tested are long gone from the market, and buying this stuff simply isn't viable for testing. Some companies send me stuff, but it's mostly the higher end stuff. Plus with my recent long term illnesses and slowness in testing their review units, I think my relationship with VLEDs is no more. Sorry VLEDs, it's not you, it's me. Show them some love if you can, that the MR2 community cares about their products. 

The capacitor needs to be at the terminal/load end to reduce the voltage drop across the wiring - it supplies current in parallel with the source so the sources current is reduced and so is the drop across the wiring.

As for class "D", the additional filtering does improve THD when looking at just a sinusoid input, but it also removes any non-sinusoidal components from the original signal, so it can never be as good as a class "A" amplifier which conducts for the entire input 360 degrees of the waveform - class "D" is less than 90 degrees of the waveform.

We need to not muck up Nottamiata's thread since we have now deviated from his questions...

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Posted by: neomr2

The capacitor needs to be at the terminal/load end to reduce the voltage drop across the wiring - it supplies current in parallel with the source so the sources current is reduced and so is the drop across the wiring.

As for class "D", the additional filtering does improve THD when looking at just a sinusoid input, but it also removes any non-sinusoidal components from the original signal, so it can never be as good as a class "A" amplifier which conducts for the entire input 360 degrees of the waveform - class "D" is less than 90 degrees of the waveform.

We need to not muck up Nottamiata's thread since we have now deviated from his questions...

Not much can be good as class A amplification obviously but at the same time no one really uses class A anymore because of the high heat and power demands.  

When comparing class A/B however the current generation of alternative amps like Class D and GH are very competitive and some high end A/B manufactures are now going in that direction because the sound quality is negligible.  I haven't use a class A amp (not tube) in many years but I did buy a portable class A headphone amp two years ago that sounded great but it was beaten out by some of the newer Muses op amp designs.  

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The new Ultinons are total garbage. About 1/5 the intensity of incandescent. Philips has been releasing embarrassment after embarrassment lately. Very disappointing. Old Ultinons are fantastic but they're usually $65 a pair to import from japan.

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There is one thing that should be mentioned. This is not anyones thread and thread drift is a normal thing that was with the community for a very long time.  

Nothing wrong with going off topic and having a discussion that might be interesting to two or more people and that is how enthusiasm can be shared. Staying on topic is what most nazi boards implement unless you want to go down that road.  

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