Battery Power for our Systems?

[roog]

However, one area I found batteries useful is DIY - building your own gear.

He he, this made me smile, as a teenager my parents wouldn’t let me use mains to power my projects, so I was stuck with using batteries, what they didn’t realise Is that I quickly learnt about switch mode step up supplies and with access to big 12V lead acid batteries before you know it I had access to hundreds and thousands of volts. I also learnt to respect charged capacitors!

 

[Cbdb2]

How does distortion, as in adding a small amount of 120, 180hz etc. make it harder to rectify. The 60hz 120v is all noise/distortion if DC is what you want. Linear supplies are only connected to the incoming AC for a small portion of the 60hz cycle, creating current spikes, so the amount of "distortion" after the diode bridge is huge even if the AC in is a perfect sine.
Do the people who come up with this nonsense even know how power supplies work?

 

[DonR]

How does distortion, as in adding a small amount of 120, 180hz etc. make it harder to rectify. The 60hz 120v is all noise/distortion if DC is what you want. Linear supplies are only connected to the incoming AC for a small portion of the 60hz cycle, creating current spikes, so the amount of "distortion" after the diode bridge is huge even if the AC in is a perfect sine.
Do the people who come up with this nonsense even know how power supplies work?

No, they don't or yes they do but hope the customer doesn't.

 

[MRC01]

How does distortion, as in adding a small amount of 120, 180hz etc. make it harder to rectify. The 60hz 120v is all noise/distortion if DC is what you want. ...

Technically speaking, wouldn't power supply harmonics be noise rather than distortion? I think of distortion as something correlated to the signal being reproduced.

 

[DonR]

Technically speaking, wouldn't power supply harmonics be noise rather than distortion? I think of distortion as something correlated to the signal being reproduced.

Well... it's distorting the desired DC.

 

[egellings]

I hung a scope on a 9V alkaline battery (AC coupling) and looked at the residue on the DC with a 2mV/square setting, and it looked as if I had tied the probe tip & the ground clip together. The battery appeared to be dead silent in that test setting.

 

[DonR]

I hung a scope on a 9V alkaline battery (AC coupling) and looked at the residue on the DC with a 2mV/square setting, and it looked as if I had tied the probe tip & the ground clip together. The battery appeared to be dead silent in that test setting.

That isn't enough resolution. To achieve a 24-bit noise floor you need a voltage reference that has less than 0.5uV ripple.

 

[egellings]

I'd need to amplify the noise of the battery before viewing it, and likely the amplifier noise would mask out the battery noise. At any rate, the battery noise is so low that I will not worry about it. Other noise sources swamp it.

 

[73hadd]

My goodness @RoyB this IS the future.

As you stated "I'm looking at it as not only a noise/performance issue"....

All of the AC to DC conversion is a waste. All of the DC back to AC is a waste. Anything that natively runs on DC should have a way to connect the DC directly.

Yes the "practicality" is not there yet, as it is early days for people with access to DC in their home. No harm in trying it out yourself. Yes there will be some DC-DC power supply complexity. Have fun and let us know how it works out!

 

[roog]

The Firm that I worked for looked at the practicalities of installing a DC mesh between desks, a plug and play system linked to batteries and PVs. The output would be DC to power devices at 19V directly.
sadly our calculations showed that this would only be practical when the office IT equipment was more like an iPad in terms of load, perhaps one day.

 

[73hadd]

The Firm that I worked for looked at the practicalities of installing a DC mesh between desks, a plug and play system linked to batteries and PVs. The output would be DC to power devices at 19V directly.
sadly our calculations showed that this would only be practical when the office IT equipment was more like an iPad in terms of load, perhaps one day.

Ugh. I hate how right you are. DC distribution in a house would require a lot of thick wire that isn't there today.

 

[jbags]

I like this topic because much of the cost of audio components is in the power supply, and chassis. Most of us have multiple components all with their own power supplies that convert AC power to DC. It is redundant and costly. Why not just use one power supple, and a 12V lead acid battery? Maybe this is just for the DIY crowd.

 

[freemansteve]

Batteries?
Pointless for a stereo.
Totally excellent for my home servers, routers and BB modems!
The so-called "pure sine" inverters are probably noisier than most mains, not that it matters for almost all stereo gear these days.

 

[eyes-on-you]

I played around with the batteries for my DAC pre-amp and electronic crossovers and as stated above it works fine but you can get just as good performance with a good AC power supply so it is not really necessary. To get batteries working right you still need large caps for filtering and more importantly to reduce the internal resistance as seen by the component. The other big issue I ran into was getting a good "split rail supply" which is required internally for any amp or pre-amp. Many people use 2 batteries in series and take the common from the middle of the 2 batteries but since batteries are not identical and age differently you will end up with unequal voltage on your split rail supply which is not good. The other solution is to build a "voltage splitter" which is not too hard for line level stuff (certainly adds complication and reduces efficiency) but gets really hard for high power applications like a power amp. Batteries seem like a good idea at first but the more you dig into it the more it does not make sense. If you want to play around with DIY stuff it can be fun though.

Reminds me ASR Emitter

 

[freemansteve]

You'd need multiple 12v batteries in series, which would still need regulation (potentially adding noise), in order to get decent volume though. You could have a DC-DC up convertor, but that is probably worse than simply using mains - switching power supplies are cheaper than many of the IC packages on many stereos.

 

[Head_Unit]

I've been thinking

STOP IT!!! You are supposed to blindly follow authority!!!
My thought: connect a Tesla battery to run the stereo

 

[chips666]

Those were the days...

 

[Leporello]

This is what we have been waiting for.

Stromtank S 1000 computer-controlled battery power source

The Kingdom of Audiophiledom rests on a paradox. Inanimate audio systems and rooms aim to deliver music that animates our senses and touches our souls. The inherently lifeless exists to bring music to life.

www.stereophile.com

 

[JeffS7444]

This is what we have been waiting for.

Stromtank S 1000 computer-controlled battery power source

The Kingdom of Audiophiledom rests on a paradox. Inanimate audio systems and rooms aim to deliver music that animates our senses and touches our souls. The inherently lifeless exists to bring music to life.

www.stereophile.com

Or you could just devise a super-efficient system around an ordinary USB-PD power bank.

 

[egellings]

So, you power your AC device with a DC source that first must be converted to AC to power the AC device that uses conventional power transformers, and then you convert it back into DC again inside the device. Seems a bit roundabout to me. Maybe the more you whip the cream, the smoother it gets.