is it possible to drive LM1875 with psu from the computer smps. Ive checked that the HDD pow cable has yellow cable which gives +12 volts and 13 amps of current for any yellow cable. So there is not less than 100watts of power that we can expect from the smps if other parts are driven properly from a 450watts smps.
But for +12 volts single power supply how much output does LM1875 can give out? its not there in the datahseet is it equivalent to +/- 12 volts or +12 volts is equivalent to +/-6volts?
But for +12 volts single power supply how much output does LM1875 can give out? its not there in the datahseet is it equivalent to +/- 12 volts or +12 volts is equivalent to +/-6volts?
The LM1875 will work at single supply 12 volts, You can expect less than 2 watts at 8 ohms or ~3 @ 4 ohms (pre clipping). The TDA2050 is a better pick as its output will swing closer to the supply rails. These chips are better suited for much higher supply voltages.
The TDA1517 is a good single ended stereo amplifier IC. If you need more power, the BTL chips made for car stereos would be best. These ICs are designed with an output swing that can get close to the supply rails and that means more power into the load. At 12 volts, you will get around 12 watts into a 4 ohm load (pre clipping) The data sheets will say 20 or 22 watts, but that is at a ridiculous 10% distortion (well into clipping) with a 14.4 volts supply.
The TDA1517 is a good single ended stereo amplifier IC. If you need more power, the BTL chips made for car stereos would be best. These ICs are designed with an output swing that can get close to the supply rails and that means more power into the load. At 12 volts, you will get around 12 watts into a 4 ohm load (pre clipping) The data sheets will say 20 or 22 watts, but that is at a ridiculous 10% distortion (well into clipping) with a 14.4 volts supply.
I always had a doubt that National chips or ST chips which gives better quality. I like the concept of just 5 to 6 components for quad channel chips from ST which still has decent figures but I somehow feel that national chips give better quality.
The application is towards PC speakers I see many companies like Cambridge soundworks, Logitech, creative use TDA chips in their pc 2.1 and 4.1 speakers but i never saw any pc speakers using National chips. I think they are expensive and also take more parts per channel altogether.
Which is good when it comes to quality of sound.
I saw TDA7560 surprisingly it uses just few components and still I think it delivers decent sound but I really suspect the quality of these chips...
The application is towards PC speakers I see many companies like Cambridge soundworks, Logitech, creative use TDA chips in their pc 2.1 and 4.1 speakers but i never saw any pc speakers using National chips. I think they are expensive and also take more parts per channel altogether.
Which is good when it comes to quality of sound.
I saw TDA7560 surprisingly it uses just few components and still I think it delivers decent sound but I really suspect the quality of these chips...
True, but as I work repairing SMPS last 2 decades, I know that replacing the -12 common anode diodes (1A e/a) with more robust 3A (It uses the same secondary winding as the +12 out), u can get up to 5 amp from -12V line, augmenting cap filtering and eventually re-winding the -12V winding in the mutually coupled common core choke. But at power level I use, none of the above mentioned mods are necessary, but capable.
Several times I rewind the trafo to get +24V 8 amps from a standard AT PSU. And at to date, they are working fine.
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the price of 4 channel x 30watt chip costs 12 USD which is pretty high for what it offers but still cant ignore of driving with low single supply voltages....
LM1875 costs close to 2 dollars so overall I can get 4 x lm1875 clean power instead of going with TDA but the problem is the PSU which gets expensive overall...
LM1875 costs close to 2 dollars so overall I can get 4 x lm1875 clean power instead of going with TDA but the problem is the PSU which gets expensive overall...
so what happens with if im driving the 10 inch subwoofer lets consider its drawing not less than 6amps peak Then will there be any problem with smps will it die? On the smps ratings it says that at +12v we can draw about 13amperes.. How much does the rest of the system draws. I can add not less than 10000uf for the psu cap at the TDA amp which might be sufficient ( I understand there wouldnt be any ripple ) but just not to load the smps for pow hungry amp. Can the SMPS sustain for this kind of load? Or shall I have more capacitance as buffer.
no idea... so how to calculate this is out of my reach... but using computers spare power is a better choice if we want to save on the transformer and capacitors... Using one 10000uf should serve the job...
I have an idea lets consider if im getting a transformer 9v-0-9v 1 amp. But with bigger diodes can we have bank of capacitors coz... the trans costs about 10$ for 2 amps and for 4 amps its 20$ instead Im getting each 10000uf for 2$ can I have good 40amp rectification diodes and then use more capacitors after the 9-0-9v 1 amp trafo?
I have an idea lets consider if im getting a transformer 9v-0-9v 1 amp. But with bigger diodes can we have bank of capacitors coz... the trans costs about 10$ for 2 amps and for 4 amps its 20$ instead Im getting each 10000uf for 2$ can I have good 40amp rectification diodes and then use more capacitors after the 9-0-9v 1 amp trafo?
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