[navin]

Your home operates on AC fed from an electrical supply. The UPS assures you of a AC supply using an inverter and a set of batteries to store the power. Thye UPS stores power in DC then covnerts it to AC for your use. But it stores the power in a battery - which is what you have in your car in the first place. IN a car we do not need AC so we do not invert it - car audio amplifiers have SMPS inside them to get a higher voltage than 12V for their internal use efficiently.

this is a typical car audio SMPS
http://sound.westhost.com/project89.htm

An SMPS has an inverter inside it.
http://upload.wikimedia.org/wikipedi...ck_Diagram.png


Hence in a car you are already at the battery end. Are you suggesting we use a second battery to back up he first battery? You would have to charge this second battery na? That would mean a bigger alternator but that damn ELD would ensure that the second battery too is not charged fast once the battery is at 12.5V orhigher (or which ever voltage it is actually set to - 12.5V is just an educated asumption).

BTW we did something similar in the old days when we used dual battery isolators, high amp alternators and 2 batteries but we did not have access to Class D amps or high amp regulators then. Fortunately we did not ELDs either!

Class D amplfier explanation.
http://en.wikipedia.org/wiki/Switching_amplifier

[Rehaan]

Originally Posted by navin

The amps are wired to the battery and the alternator charges the battery via the ELD. So while the amps are discharging the battery the alternator is unable to charge the battery (fast enough) as the ELD is in low charge mode. Untill the voltage drops to a voltage (assumed as 12V) at which the ELD goes into high charge mode. However the amps expect 12.5V (again assumed) so what is happening is that the ELD charges the battery fast from say 12V to 12.5V then goes to low charge mode. At this point (12.5V) the amps discharge the battery (faster than the battery is being charged) back to 12V where the amps go off and the ELD kicks into high chrage mode again. At high rpms the ELD is not used so there is no such problem.

This makes perfect sense navin, however...

What i can't understand is why is this causing relatively spaced out 1-second drops in the sound output?? If the amps aren't getting enough juice they should be dying for longer periods no?

Could it be a low-power issue (thanks to the ELD) that is then further triggered by an electrical device activating (which explains the 1-second drop) like the ac-compressor clutch activating or perhaps the radiator fan (<this might explain the higher frequency of dropouts in slow traffic).


Hmmm...starting load of the radiator fan... something to consider.


Anyone have one of those portable oscilloscopes? Would be interesting to see the voltage graphed as this happens.

Originally Posted by navin

b. I know every guru here does not recommend a stiffening capacitor. Still I would say try it. It costs nothing. I too suspect that at best it will reduce the number of dips (fewer charge - dischrge cycles) and not eliminate them. While I have learnt a lot from gurus I can safely say I have lernt more from just doing.

From my newbie guess at this, if there was any situation a capacitor might make sense, this might just be it!? It wont be solving the problem at the root, but it might still be a solution.

cya
R

[NetfreakBombay]

Specially since dips are for less than a second, a capacitor might help since it can supply some power during that time period and charge itself for rest of time.

[navin]

Originally Posted by NetfreakBombay

Specially since dips are for less than a second, a capacitor might help since it can supply some power during that time period and charge itself for rest of time.

I know I am talking out of both sides of my mouth but this is why while I say try it I suspect it wont work fully - a capacitor is across the battery. if the ELD does not charge the battery fast untill it hits 12V it wont charge the capacitor either. But since it costs nothing to try it, I say "why not" - stranger things have happened.

Caps and light dimming - Talk Audio

BTW Where is Sam Kapasi anyway - I was expecting his experinced input (some time back I had a crazy idea and Sam had a ffew issues with it. I told him I dont worry about these issues. We will cross them when we get to them). Sam here is another such issue. Logic says a capacitor should NOT work but since when has logic worked everytime?

Originally Posted by Rehaan

What i can't understand is why is this causing relatively spaced out 1-second drops in the sound output?? If the amps aren't getting enough juice they should be dying for longer periods no?

Could it be a low-power issue (thanks to the ELD) that is then further triggered by an electrical device activating (which explains the 1-second drop) like the ac-compressor clutch activating or perhaps the radiator fan (<this might explain the higher frequency of dropouts in slow traffic).

Anyone have one of those portable oscilloscopes?

Rehaan. Lets look at this from the amplifer's point of view.

At the onset the amp sees 14.1V and is happy as it needs only 12.5V. So the amps are humming along till the battery hits 12.4V at which point the amps turns off. A second later the battery is now at 12.3V (or whatever voltage the ELD is programmed to kick in) and the ELD kicks into high charge mode. The alternator now charges the battery to 12.5V+ (maybe the ELD is progammed to charge the battery back to 13V and go into low charge mode) at which point the amps kick in. They work till the battery has enough charge and switch off again and the ELD again kicks in .....and poor GTO gets driven round the bend.

I tell you, as an audio nut I'd prefer no system to one that behaves like this one. If I ever meet the Honda engineer who came up with this ELD idea....

I asked GTO to run the car at idle (no driving) and report.

I can expect the AC compressor to put a significant load but not the radiator fan.

GTO when the sound dips, do other electrical components - head lights, AC, etc. I suspect not since they are all rated to 12V while most car audio amplifers are rated to 13.8V (except tightly regulated ones which are rated to 12V). I am 99% sure that a Steg or JL HD series (no I am not suggesting Milbert or Butler)

Rehaan see the power supply timing chart half down this page it will tell you how car audio amplifer's power supplies work
Regulated vs Unregulated Power Supplies

[CrackedHead]

Why not add a second (high output) alternator and wire it to charge a second battery completely independent of the existing electrical's and the ELD. The entire ICE can be run off the second battery and alternator setup without caring about what the primary alternator and ELD are upto.

The existing electrical's will also thank you for taking that huge burden off them.

Other option - try something like the class GH amps - there are supposed to be happy with a wide voltage range (10 - 16 V for the Clarion DPX series that I have).

[valhallen.282]

Hang on a second. For an amp to clip for a second or two there needs to be loss of power for a little bit longer as the amps will also have slightly smaller caps. So please correct me if wrong its safe to say that the dip is happening for a good 2~5 seconds. But the amps are getting compensated internally and coming back online. So how large a cap here will be needed to compensate this. And why is it only happening when in motion is what eludes me. I can't see the pics but is it possible for someone to sit looking at the amp to see if it clips. Goes into protect or loses power completely?

[navin]

Originally Posted by valhallen.282

Hang on a second. For an amp to clip for a second or two there needs to be loss of power for a little bit longer as the amps will also have slightly smaller caps. So please correct me if wrong its safe to say that the dip is happening for a good 2~5 seconds. But the amps are getting compensated internally and coming back online. So how large a cap here will be needed to compensate this. And why is it only happening when in motion is what eludes me. I can't see the pics but is it possible for someone to sit looking at the amp to see if it clips. Goes into protect or loses power completely?

From what I understand the amp is off for less than 1 second (maybe 0.5 seconds).

Only B&T can tell if the amp goes in to protect mode.

[navin]

Originally Posted by CrackedHead

Why not add a second (high output) alternator and wire it to charge a second battery.

it was discussed....

see post 64

Originally Posted by navin

the options we have are
a. draw fewer electrical amps from the battery so that the amplifiers discharge the battery slower than the alternator-ELD combo charges it.
b. trick the ELD into asking the alternator to chrage the battery faster
c. install a secondary power source for the audio system (involves upgraded alternator, second battery and dual battery isolator).

[DerAlte]

We may be barking up the wrong tree. :-(

It will be too much coincidence for ALL the amps to clip at the same time. I would rule clipping out.

GTO, perhaps you could try out a different HU? Set all connections back to as they were. That would rule out any problem with source. Another thing you could try with the current HU would to check if the dip happens with any source - FM, CD, external media etc.

[navin]

Originally Posted by DerAlte

We may be barking up the wrong tree. :-(

It will be too much coincidence for ALL the amps to clip at the same time. I would rule clipping out.

a. it is not clipping but power loss. still i agree that for botht he VSL amd DLS amps to trip at exactly the same time is very strange.

b. DA, GTO's settings are in the HU. It has taken him 3 months to get to this set of settings. Changing the amps is an easier option. B&T has a set of Stegs available and I have told B&T that he can borrow the amps from my car too.

If the HU was losing power GTO would see it on the display of the HU.

GTO, do you see your headlights dim or your Air Con compressor cut off when your amps go off? I suspect you dont, as the ELD is probably set to come on at somwhere between 12.1V-12.5V.

[Rehaan]

Originally Posted by navin

the battery hits 12.4V at which point the amps turns off. A second later the battery is now at 12.3V (or whatever voltage the ELD is programmed to kick in) and the ELD kicks into high charge mode.

Navin, does the ELD monitor voltage (ie connected in parallel), or current being drawn (ie connected in series, before all the stock electrical equipment) ?

I read the following which made me think it was the latter :

The ELD is essentially a current transformer that monitors the amount of current draw the car is pulling from the battery. This amount varies from time to time depending on what you have turned on (various electrical devices).

Source

If the quote above is true, then i don't understand how this is happening only for 1-second.

Originally Posted by navin

I can expect the AC compressor to put a significant load but not the radiator fan.

The AC compressor is just an electrical clutch - and then the rest is all engine-driven (unlike a home AC).

The radiator fan is an electric motor, and starting power required is much higher IIRC. Just for that initial start. Once its running thats fine, but everytime it re-starts, it probably sucks much more amps than it does when running.

Atleast thats the logic i am using to suspect the radiator fan...

Originally Posted by DerAlte

We may be barking up the wrong tree.

...perhaps you could try out a different HU?

Am wondering the same too, especially now that the big amp has been taken out of the picture and this is still happening.

cya
R

[low_bass_makker]

I think we need to check the amp leave alone the car electrical. As when the speaker amp alone playing dips !!!!

[DerAlte]

Originally Posted by navin

a. it is not clipping but power loss. ...

I know. I think Valhalla's usage of the word corrupted my lazy geriatric brain!

Originally Posted by valhallen.282

... For an amp to clip for a second or two ...

Originally Posted by navin

... still i agree that for botht he VSL amd DLS amps to trip at exactly the same time is very strange.

Originally Posted by low_bass_makker

I think we need to check the amp leave alone the car electrical. As when the speaker amp alone playing dips !!!!

All the 3 amps plunge for a short while, so it cannot be the amp's fault.

Originally Posted by navin

... b. DA, GTO's settings are in the HU. ...

:-( and no way to take backup of settings! The only way it to patiently note down the value against each and every parameter.

[valhallen.282]

No no there's something missing here. There's something missing. @GTO sir please tell us at PRECISELY what point this happens. At a signal or in traffic as you lift off the clutch. When you brake. With a/c on a/c off. Just as you gas it. At PRECISELY what point. If it recurrs sufficiently it might be something else. But please be very clear at what point it happens.

On another note There was an old old article when me and a friend were researching electric cars that said that in certain modes the alternator is cut off while start off to prevent power losses. But the above point for understanding is very important.

[bhp_maniac]

I don't know whether anybody has discussed this here. Forgive me if so.

When saying sound is dipping for a fraction of a second, it can happen by two things.

1. Amp losing power input and thus switching off.
2. Amp not getting signal input (from HU) for a fraction which causes the issue.

My take is as Navin said, all the 3 amps switching off at the same time is kind of strange. So, what if the source of the amps are not giving the signal (HU) for a very little time, which is causing the issue? Or, GTO has confirmed that the amps are switching off and the HU is feeding signals? My suggestion is to wire a set of speakers from the HU amp itself to confirm that the HU is not the weak point here. I think the regulators inside the amps will compensate any voltage variations till 12.1V. And even if there is a thing like ELD, it might switch to high charging before the trigger voltage of 12.1? Or am I sounding stupid?

The other side of my assumption is that, even though for a fraction of a second if the HU is switching off, it will result in a reset of the "now playing" track as digital circuits are sensitive to power loss for even fraction of a second. But, what if only the pre-amp section in the HU is having the issue and the other circuitries are working as expected?