Electronics > Beginners
Loud Speaker?
madires:
--- Quote from: ChrisGreece52 on May 30, 2013, 11:59:37 am ---I dont want something loud because i will mostly use my pc speaker system (25watt RMS).
--- End quote ---
Which type do you got? Stereo squawk plastic boxes, 2 tiny speakers with a subwoofer cube or something more usable?
madires:
--- Quote from: ChrisGreece52 on May 30, 2013, 12:03:18 pm ---So i wont do it because i will use frequencies as low as 30 HZ.
--- End quote ---
The 2" speakers will fall off around 100Hz very quickly, maybe even at a higher frequency.
mariush:
--- Quote ---The transformer in the picture is a 500mah 9 volt one but i will need more info about connecting it in parallel so i can increase the voltage
--- End quote ---
Dude...
You have voltage.
You have current.
Voltage multiplied by current gives you power.
That transformer is 9v 0.5 A ... that's 4.5 watts.
No matter how many you put in parallel, the voltage remains 9v, just the current doubles, triples etc
No matter how many you put in series, the current remains 0.5A, just the voltage doubles, triples etc
9v is too low for a tda2050. No matter how much current you'd have by putting transformers in parallel, you still have just 9v. If it starts at 9v, a tda2050 will only output about 1-2 audio watts, so the chip will only use about 3-5 watts (0.3-0.5 amps) out of how many amps your transformers in parallel would be able to provide.
If you put 9v transformers in series, you may have 18v, 27v, 36v ac or dc but your current will still be 0.5a
Let's say you put 3 in series to get 27v 0.5a. That's 13.5 watts. I don't know if it's 9v ac rms or 9v DC coming out of that. Let's just say 27v DC.
If you go in datasheet at the graph, you look at +/- 13v (because the graph is for split power supply) and you see the amplifier chip has the potential to output up to about 7 watts. At about 60-70% efficiency, that means that to output a single channel (one amplifier), to output about 7 watts of audio, the chip will use about 10 watts.
Your 27v 0.5a will be enough, for ONE channel.
If you put two amplifiers, one for each channel in stereo, they'll both use about 10 watts, 20 watts in total... but your power supply can only provide 13.5 watts. Your power supply is undersized, even with 3 transformers of that type in series.
Do you understand the concept that the amplifier can not output audio watts if there's not enough power at the input? If you give it 10 watts from the mains, how do you expect to get 20 audio watts?
Use that 9v transformer for other stuff, it's not suitable for audio amplifiers.
Like I said, you need something like 24v AC rms 40-60 VA (about 1.5A) to get about 20-25w of sound.
ChrisGreece52:
--- Quote from: madires on May 30, 2013, 12:48:59 pm ---
--- Quote from: ChrisGreece52 on May 30, 2013, 11:59:37 am ---I dont want something loud because i will mostly use my pc speaker system (25watt RMS).
--- End quote ---
Which type do you got? Stereo squawk plastic boxes, 2 tiny speakers with a subwoofer cube or something more usable?
--- End quote ---
Something more usable its pretty old but still going strong
Its a Logitech X-420 2.1 system.
2 satelites and one subwoofer
http://www.newegg.com/Product/Product.aspx?Item=N82E16836121010
I got it for about 7 years .... ( i did not know that it has been so long ... )
good quality wooden woofer and i think it is the best i had (and the first i had :P )
ChrisGreece52:
--- Quote from: madires on May 30, 2013, 12:53:18 pm ---
--- Quote from: ChrisGreece52 on May 30, 2013, 12:03:18 pm ---So i wont do it because i will use frequencies as low as 30 HZ.
--- End quote ---
The 2" speakers will fall off around 100Hz very quickly, maybe even at a higher frequency.
--- End quote ---
well that sucks.......
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version