I would like to build a pair of micro-size active speakers to be used with my girlfriend's laptop computer. I have a pair of 2" Peerless PLS-P830970 full range speakers which I would like to utilize. Its data sheet can be viewed here:
http://www.tymphany.com/files/PLS-P830970 Rev1_0.pdf
TDA 2822M chip amplifier would be very simple to use and it should be possible to power it directly from the USB +5V line.
I reckon a standard USB port can provide about 2½ watts of power. Would it be okay for a pair of TDA 2822M chip amps?
I've also considered adding a micro-size (3", 4"?) subwoofer speaker to augment the mid-bass response a bit, but would the power output from a standard USB port be inadequate for that?
http://www.tymphany.com/files/PLS-P830970 Rev1_0.pdf
TDA 2822M chip amplifier would be very simple to use and it should be possible to power it directly from the USB +5V line.
I reckon a standard USB port can provide about 2½ watts of power. Would it be okay for a pair of TDA 2822M chip amps?
I've also considered adding a micro-size (3", 4"?) subwoofer speaker to augment the mid-bass response a bit, but would the power output from a standard USB port be inadequate for that?
Attachments
Hi,
The reality is you will be totally wasting your (expensive)
time attempting to do this, its simply not worth the effort.
These are great for the minimal cost and USB powered :
Amazon.com: Logitech S150 USB Speakers with Digital Sound: Electronics
rgds, sreten.
The reality is you will be totally wasting your (expensive)
time attempting to do this, its simply not worth the effort.
These are great for the minimal cost and USB powered :
Amazon.com: Logitech S150 USB Speakers with Digital Sound: Electronics
rgds, sreten.
I have built both the stereo and bridged mono amplifiers on a prototype board and they seem to work fine. I used a 9V battery as a power supply during testing.
I also tried to add a simple op-amp lowpass filter circuit into the bridged mono amp to drive a 4" TB as a tiny bass speaker; however I get only strange 'burping' sounds and see the speaker cone rapidly moving back and forth even when no input signal is applied.
I tried the attached circuit with op-amp chips LM358, TLC2272, LF353 and MC1458P. The component values used were:
Cin = Cout = 10 uF
R1 = R2 = 22k
C1 = 100 nF
C2 = 200 nF
I also tried to add a simple op-amp lowpass filter circuit into the bridged mono amp to drive a 4" TB as a tiny bass speaker; however I get only strange 'burping' sounds and see the speaker cone rapidly moving back and forth even when no input signal is applied.
I tried the attached circuit with op-amp chips LM358, TLC2272, LF353 and MC1458P. The component values used were:
Cin = Cout = 10 uF
R1 = R2 = 22k
C1 = 100 nF
C2 = 200 nF
Attachments
Thats either a ground loop coming through your RCA connectors. (if the line-in cable is still connected to something which is running from mains, try using an iphone/ipod/laptop (not plugged into the wall). or you are picking up interference some other way. Or you've got an oscillation somewhere in the circuit, somewhere a resistor and capacitor are causing an oscillation. A capacitor is being charged by a resistor and the cap is discharging, rinse and repeat. http://en.wikipedia.org/wiki/RC_oscillator
I bought one of these and was quite happy: Stylish Portable USB Powered Laptop/PC Speaker (USB Jack) - Free Shipping - DealExtreme
That usb speaker off dx sounds great by the way, and is fairly loud up to a point, but its nice and clear and loud up until then.
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I have tested the TDA2822M amp chip in both stereo and mono (bridged) operating modes, but I soon became really put off by the amount of static background noise it produces. We find it unbearable even for this kind of miniature laptop sound system. After applying power to the circuit without any input (but cable connected), the sound from the speaker(s) is like somebody just turned on a fan.
Both configurations (stereo/mono) exhibit this behavior and it seems like I have to choose another amplifer IC to be used in this project...
Both configurations (stereo/mono) exhibit this behavior and it seems like I have to choose another amplifer IC to be used in this project...
http://www.diyaudio.com/forums/full...r-speakers-what-you-can-get-25-usd-15gbp.html
Hi,
The above is far better than a simple driver in a box with an amplifier.
rgds, sreten.
Hi,
The above is far better than a simple driver in a box with an amplifier.
rgds, sreten.
schematic diagram audio amplifier tba820
That is definitely not the fault of the TDA2822.
There could be many reasons why... and without seeing the construction/layout etc and putting a scope on it I wouldn't want to guess but the TDA2822 isn't the fault.
Haven't checked my thread in a while. Thanks for your replies.
I have built a stereo amplifier with an amplifier chip (AN7522) from an old car radio. I followed the schematic on the datasheet. The amplifier uses a 12VAC wall cube as a power supply and it has an LM317 voltage regulator IC with additional transistor.
The heat sink is originally from a broken car audio amplifier and it's clearly too big. I might change it to a smaller one to save some space.
I have built a stereo amplifier with an amplifier chip (AN7522) from an old car radio. I followed the schematic on the datasheet. The amplifier uses a 12VAC wall cube as a power supply and it has an LM317 voltage regulator IC with additional transistor.
The heat sink is originally from a broken car audio amplifier and it's clearly too big. I might change it to a smaller one to save some space.
Attachments
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