Power supply and creative inspire 2.1 2500 question

In summary: A fuse would be necessary to protect the speaker if the current drew exceeded the rated current of 1.5A.
  • #1
saad ahmed khan
46
0
urgent power supply and creative inspire 2.1 2500 question

hello every one

this is urgent...

i am trying to fit computer speakers in a car
the computer speakers need 12V@ 2.9 A DC
the car battery is of 12V DC but of a lot more amperes

the problem is i want to make a filtered power supply for the speakers that puts out exactly 12V DC@ 2.9A not more and not less

i know from experience that if more current is applied speakers tend to pump a lot which leads to damaged speaker cones

can you guys help me make this power supply
the input is 12V from car battery
and car batteries are mostly rated at something abt 50 AMPERES

also does anybody here own a creative inspire 2.1 speaker system model 2500

can that person tell me if it is possible to run those speakers of 12V

thanks in advance
 
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  • #2
The current drawn is the current demanded not the current supplied.
Your Car Battery will easily supply 3 times the rated current but that current isn't going to go into your speakers.
Check your basic electronic principles.
 
  • #3
i forgot to mention
2.9A is the current supplied

the circuit will take more than 2.9 amperes the circuit will not be damaged
but the excess current will go to the speakers and cause them to pump more
that i know from experience

but how would you make the filtered circuit just to make sure not more than 2.9 amperes is supplied
 
  • #4
" i am trying to fit computer speakers in a car
the computer speakers need 12V@ 2.9 A DC"

This sounds like you are trying to power a set of computer speaker that includes its own amplifier. If so, just use your car battery for the supply. The 2.9 amps is the current that the amplifier will "take" from your battery.

Regards
 
  • #5
With car audio it always pays to take the feed directly from the battery, but I doubt it'll really make much difference with just 3A or so.

And saad, the replies are correct, the 2.9A is the (rated) current the transformer will draw. If you want to ensure that no more than this is ever drawn, you could use a fuse...
 
  • #6
saad ahmed khan said:
i am trying to fit computer speakers in a car
the computer speakers need 12V@ 2.9 A DC
the car battery is of 12V DC but of a lot more amperes
The problem is that a car is NOT 12v.
The car will provide about 13.6v when the engine is running.
This is why your computer speakers will draw more current.
It has nothing to do with the fact that a car battery can source more amperes.

Probably the cleanest solution to "Filtering" in this case is to use a DC-DC converter.
 
  • #7
"also does anybody here own a creative inspire 2.1 speaker system model 2500"

i was thinking of doing the same with my 2.1, 2400 speakers. it needs 12V, 1.5A. will it effect the system if voltage goes up to 13.6V?

i agree with NoTime, using a DC-DC converter. but i would use a DC-AC converter so u can easily plug ur speaker into the converter and don't have to worry about over voltage or current.
 
  • #8
sajid07 said:
but i would use a DC-AC converter so u can easily plug ur speaker into the converter and don't have to worry about over voltage or current.
In some cases the square wave output of common DC-AC converter can cause problems.
Many things will work just fine on the square wave output.
Just a thought in case you end up with issues.
An option here would be a sine wave inverter (more expensive).

Note that the generic wall wart 12v supply provides no voltage or current regulation.
 
  • #9
tell me if it'll work. assuming the battery while engine running, gives 13.6V suppling 50A. connecting a resistor in parallel to the source taking up 48.5A. A fuse of 1.6A connected in series between the resistor and the load. ill choose the resistance of the fuse so supply would reduce from 13.6 to 12V.
so i can get 12V and 1.5A through the load, i.e. speakers. the fuse should protect the speakers if current exceeds.

NoTime, what did you mean by generic wall wart?
 
  • #10
sajid07 said:
tell me if it'll work. assuming the battery while engine running, gives 13.6V suppling 50A. connecting a resistor in parallel to the source taking up 48.5A. A fuse of 1.6A connected in series between the resistor and the load. ill choose the resistance of the fuse so supply would reduce from 13.6 to 12V.
so i can get 12V and 1.5A through the load, i.e. speakers. the fuse should protect the speakers if current exceeds.
No - It won't work.
The amp determines how much current it will draw not the battery.
Also the current is NOT constant and will vary with the volume.
With the volume set to zero the current will be only be about 0.02A.
Very much less than the max current of 1.5A.

The potential for a problem here is that 13.6v input can increase the ability of the amp to produce power.
Power is voltage times current not either one by itself.
If the amp produces more power than it was designed for it will burn out.

sajid07 said:
NoTime, what did you mean by generic wall wart?
The little black box you plug in the wall that they give you to power your amp.
 
  • #11
sajid07 said:
"i agree with NoTime, using a DC-DC converter. but i would use a DC-AC converter so u can easily plug ur speaker into the converter and don't have to worry about over voltage or current.


I think you may be getting confused, or else your initial post was missing something. You said you needed 12V 2.9A DC and now you are talking about a DC-AC converter.

If your AMP wants to draw more than 2.9A and 2.9A is all there is available then the volts will drop in the AMP. You could use a DC-DC converter but a simple 12V regulator or even a simple zener diode regulator will give you a smooth enough 12V signal for your AMP.

You obviously want to use something not compatible with the CAR stereo e.g. IPOD.
Have you got a Stereo in the car already?
If so you can get tape convertors that you put into the cassette slot and then can plug in any device with a headphone socket and it plays through the Cars speakers.
 
  • #12
Panda said:
a simple 12V regulator or even a simple zener diode regulator will give you a smooth enough 12V signal for your AMP.
Most 12v regulators require about 14v to operate properly.

A zener, or the equivalent in a circuit since the normal zener internal resistance is too high, needs to dissipate about 20w in this case.
Thats quite a bit of heat to get rid of.
 
  • #13
guys your right, i totally forgot volume depends on current.
thx
 
  • #14
hi again guys

the computer speakers are being used to replace the car speakers
the car speakers are very old and its cheaper to get computer speakers than car speakers for providing good sound

i first used a 7812 regulator but that did not work properly because its not capable of providing 2.9A. then i looked up an NTE1912 but was not sure wether it would work with a supply of 12V
then i got tired of it and used a 5A car fuse (i could not find a 3A car fuse) i will replace that with a 3A fuse later on.
that took care of the power supply and the speakers worked properly.
then i hit another snag. that was the input to the speakers from the car tape. the car tape is a very old one and does not have any line out options for using with amplifiers. i first directly connected the speakers to the input.
but the power to the speakers was about 30Watt. hence the amplifier of the speakers worked well at very low volumes. any higher and the distortion was too great. then i thought that since the sound signal to the speakers is AC so i thought "why not use a step down transformer" so i took 2X 2A 220V to 12V transformers. connected the 220V side to the car speakers and used the 12V side as input for the amplifier.
the sound was ok but it was a bit too low. the amplifier when used in it original setting provides awesome sound but it did not go to that level in the car. but still the sound quality is pretty good.

but i want to improve this as the way of taking the input is not exactly proper
i just had the materials to hand and improvised.
please tell me if you guys have any suggestions, or if there is a proper circuit for providing a proper input can anybody send me the circuit diagram
my email id is guess_whosak@hotmail.com
 
  • #15
Wire an op-amp to the signal from your tape deck. Something like an LM386 should work great (last I can recall). If you use a power transformer, you're going to have a lot of problems with getting the sound frequencies through. It'll probably sound really "tinny". Try finding an audio transformer if you want to go that route. Jenson is known to make some nice ones.
 
  • #16
thanks triden
i am thinking too about the audio transformer
i asked some electronic shop owners in my area thet were also saying that there is some sort of transformer for my application but no one could point out exactly what it was
do you have any pics or links about the transformer
 

1. How do I properly connect my power supply to the Creative Inspire 2.1 2500?

To properly connect your power supply to the Creative Inspire 2.1 2500, first make sure that the power supply is compatible with the speaker system. Then, locate the power input on the back of the subwoofer and plug in the power supply. Finally, plug the other end of the power supply into a working power outlet.

2. What is the power output of the Creative Inspire 2.1 2500?

The Creative Inspire 2.1 2500 has a power output of 25 watts for the subwoofer and 10 watts for each satellite speaker, giving it a total power output of 45 watts.

3. Can I use a different power supply for the Creative Inspire 2.1 2500?

It is not recommended to use a different power supply for the Creative Inspire 2.1 2500 as it may not be compatible and could potentially damage the speaker system. It is best to use the power supply that was specifically designed for this speaker system.

4. Can I leave the power supply plugged in all the time?

Yes, you can leave the power supply plugged in all the time as long as it is not overheating or causing any issues. However, it is recommended to unplug the power supply when not in use for extended periods of time to conserve energy and prevent any potential hazards.

5. What should I do if my power supply is not working?

If your power supply is not working, first check to make sure it is properly connected and that the power outlet is functioning. If the power supply still does not work, you may need to replace it with a new one. Contact the manufacturer for further assistance if needed.

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