I know that this may sound like a strange question, but...
Is there a way to power a F4 or F5 by way of batteries? Is there a way to split 48VDC into +/-24VDC for the power supply? I have no problem coming up with 48VDC or even higher. It may sound better or worse if at all possible. Some big caps is the PS and skip the rectifiers. Is this possible?
Most of you will be asking why? Simple, the land I am buying is a fair distance from the grid and it will cost a fortune for a line in and I will not use a generator. I will be using solar, therno-electric, and micro-hydro, to power the house. I am building a 12V TEC fridge/hot water heater, cold side fridge and the hot side to a water tank. I may build a DIY projector to run on 12v with LED as a light source. All other electric appliances are 12V or 24V with the exception of:
-HTPC media server
-FirstWatt amps
-Soldering iron 110V (need 220v)
The PC is easy. I would power the PC with a DC-DC smps and the Julia with a seperate battery. The soldering iron will need an inverter. I will use this inverter for guests gadgets and inevitable AC needs. However, I would like to keep it small and not have the need for the FW to be driven off it. It must be a relatively cheap solution otherwise I will just buy a big inverter or scrap the FW amps and build a set of chip amps for 12v-24v DC battery. All suggestion are welcome and if you have any wild and crazy ideas, I want them too.
Is there a way to power a F4 or F5 by way of batteries? Is there a way to split 48VDC into +/-24VDC for the power supply? I have no problem coming up with 48VDC or even higher. It may sound better or worse if at all possible. Some big caps is the PS and skip the rectifiers. Is this possible?
Most of you will be asking why? Simple, the land I am buying is a fair distance from the grid and it will cost a fortune for a line in and I will not use a generator. I will be using solar, therno-electric, and micro-hydro, to power the house. I am building a 12V TEC fridge/hot water heater, cold side fridge and the hot side to a water tank. I may build a DIY projector to run on 12v with LED as a light source. All other electric appliances are 12V or 24V with the exception of:
-HTPC media server
-FirstWatt amps
-Soldering iron 110V (need 220v)
The PC is easy. I would power the PC with a DC-DC smps and the Julia with a seperate battery. The soldering iron will need an inverter. I will use this inverter for guests gadgets and inevitable AC needs. However, I would like to keep it small and not have the need for the FW to be driven off it. It must be a relatively cheap solution otherwise I will just buy a big inverter or scrap the FW amps and build a set of chip amps for 12v-24v DC battery. All suggestion are welcome and if you have any wild and crazy ideas, I want them too.
If you have a battery bank that is 48vdc total, it's not hard to get +/- 24vdc at all. All you have to do is tap at the 24v point of the battery bank and call that your ground for the amp. Then anything to the positive side of this tap is your +24v and anything to the negative side is -24v. However, you're probably going to need some serious current capacity to run any of the First Watt (or any other Class A power amp) off of batteries. I reality, if you do run your amps off of batteries, and the batteries are close enough to the amps, you really don't need the big filter caps that are usually in the PS.
Peace,
Dave
P.S. For the soldering iron, you can buy ones that are designed for automotive usage that run off of 12vdc. You can also get ones that run off of lighter fluid and other flammables.
Peace,
Dave
P.S. For the soldering iron, you can buy ones that are designed for automotive usage that run off of 12vdc. You can also get ones that run off of lighter fluid and other flammables.
I like my iron, I will either mod the thing to accept 220v or sell it and buy one in that voltage which would probably be easier. However, I will need a small inverter anyway and it will be in my "mad laboratory" anyway. I have been trying to figure out how much battery I need. SLA car batteries are around 13v charged, right? How long would four 1000ah batteries last with a F5? A smps is an opton, but I still need the same amount of battery and this adds a lot to the price. They sell huge 12v and 24v batteries over there for cheap. My PS may be 3' x 2', LOL!
So aside from the battery size, how would I do it? If I have two 24V batteries, I connect them in series to make 48V. I then wire the positive rail to the positive terminal of the 48V bank, the neg to the neg and the ground in the middle where the two batteries join. It can't be that simple, can it? The extra capacitance is something I learn from my youthful car audio days. The amp likes current faster than the battery can deliver. I found this is true of unregulated PS class A/B amps anyway.
What would I do between the battery and the amp boards for protection, current regulation, and so on?
How many amps would a F5 draw off the battery? If it uses 100w per channel, or about 4A right? If that is the case a 1000AH battery should last how long?
So aside from the battery size, how would I do it? If I have two 24V batteries, I connect them in series to make 48V. I then wire the positive rail to the positive terminal of the 48V bank, the neg to the neg and the ground in the middle where the two batteries join. It can't be that simple, can it? The extra capacitance is something I learn from my youthful car audio days. The amp likes current faster than the battery can deliver. I found this is true of unregulated PS class A/B amps anyway.
What would I do between the battery and the amp boards for protection, current regulation, and so on?
How many amps would a F5 draw off the battery? If it uses 100w per channel, or about 4A right? If that is the case a 1000AH battery should last how long?
Surprise, but yes it is that easy to get the +/- 24vdc you need for the amp. In regards to the need for caps to buffer the amp from the battery, this is largely due to the distance between the battery and the amps. The longer the cable run, the more resistance and inductance between the battery and amp. This causes voltage drops and power response lags. If the batteries are in a central bank, away from the amp, then yes, you should have caps for each channel, each voltage rail (or you could have a sub battery bank near the amps) . But if the batteries are setup near the amps, and are only used for the amps, then you shouldn't have issues with this sort of lag. Soon others will disagree.
Don't bother with an SMPS in the path. Any sort of power conversion provides a further loss of available total power, thus efficiency loss. If you have the correct voltage already available, use it directly.
I don't recall if the F5 is a constant current design, but if it is, and each channel uses 4A, then you will draw 8 amps total for a 2 channel system. If you divide 1000Ah by 8 this will tell you the total amount of time you could run the amps, assuming that nothing else is running off of the batteries. Also keep in mind that you don't want to discharge the batteries too much, it will permanently damage them.
I can't answer for Zen Mods suggestion of going smaller in your current demand, or in regards to particular transistors, but I understand what he is saying. Lower your power demands for each amp channel and the batteries will last for a longer amount of time before they need a recharge.
Peace,
Dave
Don't bother with an SMPS in the path. Any sort of power conversion provides a further loss of available total power, thus efficiency loss. If you have the correct voltage already available, use it directly.
I don't recall if the F5 is a constant current design, but if it is, and each channel uses 4A, then you will draw 8 amps total for a 2 channel system. If you divide 1000Ah by 8 this will tell you the total amount of time you could run the amps, assuming that nothing else is running off of the batteries. Also keep in mind that you don't want to discharge the batteries too much, it will permanently damage them.
I can't answer for Zen Mods suggestion of going smaller in your current demand, or in regards to particular transistors, but I understand what he is saying. Lower your power demands for each amp channel and the batteries will last for a longer amount of time before they need a recharge.
Peace,
Dave
dave_gerecke said:
You could do that,BUT,you will have to consider the 'ground' points for the rest of the system.
Often RE battery banks are grounded at the negative end (0V),if you tap the center of the bank and use that as the amp ground,then the 'ground' of the amp will be floating at 1/2 of the battery bank voltage. If you were to connect the amp,to say,a preamp that's grounded at 0V,you're gonna have 1/2 of the battery bank voltage flowing through your interconnects! And we all know BIG batteries can supply BIG currents.
Just be sure to consider all of the current paths,before you start connecting things together.
DigitalJunkie said:
You could do that,BUT,you will have to consider the 'ground' points for the rest of the system.
Often RE battery banks are grounded at the negative end (0V),if you tap the center of the bank and use that as the amp ground,then the 'ground' of the amp will be floating at 1/2 of the battery bank voltage. If you were to connect the amp,to say,a preamp that's grounded at 0V,you're gonna have 1/2 of the battery bank voltage flowing through your interconnects! And we all know BIG batteries can supply BIG currents.
Just be sure to consider all of the current paths,before you start connecting things together.
Good point, I didn't think that one fully through before making the comment. If you do setup your power supply to the power amps this way, you would want to setup the rest of the system this way, otherwise you will have problems like those mentioned by DigitalJunkie. UH OH, Magic Smoke!!!!
Peace,
Dave
My set-up will be a Buffalo-ish DAC from Twisted Pear to Lundahl LL1674 trannies for I/V to Aikido 24V preamp, to the F4 or F5, to Audio Nirvana 12". The DAC is easy for batteries, the preamp all DC inside and easy for batteries and the only hiccup I can see is the amount of battery I will need. So what should I be doing then to avoid this "current" problem?
How do you avoid this with a normal "Virtual ground" PS?
Could I wire each on their own batteries and isolate each component completely except the signal?
How do you avoid this with a normal "Virtual ground" PS?
Could I wire each on their own batteries and isolate each component completely except the signal?
Hello khundude, not knowing the schematics of the various equipment you mention, it's hard to say the proper way to wire things up. If you can post links to the schematics for all of your equipment, people can look at the power supply demands for each and recommend proper wiring from that.
Peace,
Dave
Peace,
Dave
The DAC needs +6VDC and +3.3VDC. I would use a vreg for this. The preamp requires +24vdc and the amps require +/-24VDC. Each amp would draw 8A, the DAC is less than 100mA and the preamp will draw about about 1A. This is at their respective voltages.
I think that I must use four 12v batteries with the ground in the middle. This would be + on the right and - on the left. In the middle I would wire the DAC on the first +12V and both the B+24v preamps go to the first two. This would give me +25.2, +12.6, 0, -12.6, -25.2. Does this sound right?
I think that I must use four 12v batteries with the ground in the middle. This would be + on the right and - on the left. In the middle I would wire the DAC on the first +12V and both the B+24v preamps go to the first two. This would give me +25.2, +12.6, 0, -12.6, -25.2. Does this sound right?
I had a similar but different problem. I live in North America, nearly every piece of hifi is made to run of 117 volts ac. I have a swimming pool pump in a shed it runs of 220volt. I wanted hifi outside. Solution #1 was to use an old AT computer power supply, 12volts at 5amps and 5 volts at 15 amps. The 5 volts powers some lights. Most computer power supplies have a 110/220 switch. Get a decent car stereo and volia! hifi, well maybe not really hifi. My son wanted more volume for his "parties". So he bought for me on fathers day a 4x50watt car stereo. The at power supply wasn't enough. I found a 15volt 3 amp linear power supply in a surplus store that was wired for 220volts. I changed the output to 13.8 volts and bought a 750 car battery that has more than enough juice for the new car stereo. With 4 speakers all set up and cranking, the battery has easily outlasted every party so far. When the pool pump is running the battery is charging. Most people that have to supply their own hydro power seem to count every watt that is used. Too many cloudy days and oops no fridge oops no heat oops no water pump. They would never use Class A power amps, way too wasteful of energy. Class d might be a better option for you.
True. The First Rule of RE/off-grid power: Conservation is cheaper (and easier) than generation. Extra solar panels and batteries are $pendy.
If you're hell-bent on using the big beastly amps,the isolated split supply with batteries that you mention should work out fine. It will need to have it's own charger though (seperate solar panels/wind genny/whatever).
Four big 1000ah batteries cost about $400. The truck alternator, $100. Thermo-electric generator, $100. $600 for two class A amps, balanced preamp, DAC is very cheap! Tranformers would cost $300, PS for FW $100, PS for preamp $100, PS for DAC with shunt regs $400. Batteries are also cheaper to run. The power is almost free, how much would I spend on power in the next 10 years? So I would initially spend more on PS for AC line and have to pay for power and it will likely sound worse.
Guys, why don't you try this one. solar power generator. I think it will help you. Leave me a comment. Thanks
I'm wondering, where are you getting 1000AH batteries for $100 a piece? I have these Exide Orbital 34XCD units that are rated at 50AH and cost $175 Ea. They weigh 50lbs each. If I had 1000AH of these things that would be 20 batteries! If I had 48Volts worth, that would be 80 batteries!!! At 50lbs ea. that's 4000lbs and $14,000. I have seen such a pile of batteries before but $100?
I would guess you do have a good bank of batteries for a home, with reserve and all but, I'm just interested, what rate is this rating at. Marketing for batteries has lots of influential bull%^ & "specs" and it gets a little squirly sometimes. Not to mention the non-linearity of battery charge/discharge rates. For instance, that 50AH rate for my Exide battery is the typical US standard of 20hr. That is, it will do 2.5A continuos drain for 20 hours. It will sustain a continuous drain of 25A for about 1.66 hours. It will last about 30 seconds at 1000A.
I suppose I should go into the math of what you probably need for the sound system instead but, it easily gets confusing...
The biggest question is, how long do you need to listen before you need a recharge?
$100?I would guess you do have a good bank of batteries for a home, with reserve and all but, I'm just interested, what rate is this rating at. Marketing for batteries has lots of influential bull%^ & "specs" and it gets a little squirly sometimes. Not to mention the non-linearity of battery charge/discharge rates. For instance, that 50AH rate for my Exide battery is the typical US standard of 20hr. That is, it will do 2.5A continuos drain for 20 hours. It will sustain a continuous drain of 25A for about 1.66 hours. It will last about 30 seconds at 1000A.
I suppose I should go into the math of what you probably need for the sound system instead but, it easily gets confusing...
The biggest question is, how long do you need to listen before you need a recharge?
O.K. so, if it were me, I'd like to have at least 5 hours of listening without a recharge. Sure more would be better but some of us would like a relatively thought out estimation of what this would take. I'm not powering the rest of my house and I can recharge overnight or whenever. In your home in the boonies, you don't always have that luxury. You may not have sun, you may not have running water power(ice?), you may not have wind, and even if your on the grid, the ice that froze the river can bring down the lines too.
So, a std F5 is going draw 2.6A continuos from 4 12V batteries. Maybe, for the sake of estimating, all your other pre, TT, CD, DAC, etc. draws another 2.4A. That's 5A total continuos current draw from the 48V battery bank.
Batteries like my Exide 34XCD will perform well for many hundreds, maybe thousands, of recharges if only discharged to 50%. This is a good rule of thumb to shoot for. In other words, take your battery requirement and double it, to maintain the highest reliability and battery life.
I wanted 5 hours of 5A I need a 25AH battery. But, just in the case the grid is down, or I'm having a big continuos party or I just want the best reliability and battery life I need a 50AH battery
When I was younger, I did exactly that. I had a floating "river stereo" that tubed down the river for 4-5 hours every weekend. Amongst other things it had an AM/FM cassette deck, a 100w/ch Carver amp, a 100W/ch JVC amp, a fan and an opamp based active crossover - EQ circuit. With the music blasting, as long as it wasn't playing the 1812 ovature, a current measurement would average over 5 amps. After 4-5 hours, we still had power to blast it on the way home. the battery I was using was less than 50AH. After all that. the battery would be down to 10.5-11V. The standard (US) method for rating AH is the Time x Current that it takes to discharge the battery to 1.75V/cell (10.5V for a 12V battery). My river system did just about that.
One other thing. You would find it difficult to match the peak current capability of a descent battery for the money.
Insane?
So, a std F5 is going draw 2.6A continuos from 4 12V batteries. Maybe, for the sake of estimating, all your other pre, TT, CD, DAC, etc. draws another 2.4A. That's 5A total continuos current draw from the 48V battery bank.
Batteries like my Exide 34XCD will perform well for many hundreds, maybe thousands, of recharges if only discharged to 50%. This is a good rule of thumb to shoot for. In other words, take your battery requirement and double it, to maintain the highest reliability and battery life.
I wanted 5 hours of 5A
I need a 25AH battery. But, just in the case the grid is down, or I'm having a big continuos party or I just want the best reliability and battery life I need a 50AH battery When I was younger, I did exactly that. I had a floating "river stereo" that tubed down the river for 4-5 hours every weekend. Amongst other things it had an AM/FM cassette deck, a 100w/ch Carver amp, a 100W/ch JVC amp, a fan and an opamp based active crossover - EQ circuit. With the music blasting, as long as it wasn't playing the 1812 ovature, a current measurement would average over 5 amps. After 4-5 hours, we still had power to blast it on the way home. the battery I was using was less than 50AH. After all that. the battery would be down to 10.5-11V. The standard (US) method for rating AH is the Time x Current that it takes to discharge the battery to 1.75V/cell (10.5V for a 12V battery). My river system did just about that.
One other thing. You would find it difficult to match the peak current capability of a descent battery for the money.
Insane?
It sounds like heaven in many ways, but what are you going to do for an internet connection?
You have the Audio Nirvanas. You may like the class A amps, but they really are crazy when you could have a Sonic Impact or other TA2024 amp that would run off 12V, tolerate a fully charged 12V battery section, give you plenty of volume and run forever off 1000Ah x 4 You can then run everything off 12V with regulators to provide the lesser voltages (switch mode if you wanted), everything can have the same ground, and even if you had linear regs the power wastage would be comparatively trivial.
w
You have the Audio Nirvanas. You may like the class A amps, but they really are crazy when you could have a Sonic Impact or other TA2024 amp that would run off 12V, tolerate a fully charged 12V battery section, give you plenty of volume and run forever off 1000Ah x 4 You can then run everything off 12V with regulators to provide the lesser voltages (switch mode if you wanted), everything can have the same ground, and even if you had linear regs the power wastage would be comparatively trivial.
w
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