SD12kD inside view - How it works

[murilo 10+ year member]

Hello

With this basic highlights we can discuss a little bit how the amplifier works.

A- Power transformers: they are connected to the battery positive +12V (or any voltage in the 8-18V range) and to the Power supply FETs, which will open and close (controlled by the microprocessor) and generate an AC voltage on their outputs.

B- Power Supply FETs: explained on A. Each one is rated at 202A continuous, but they can handle up to 4x this number by working pulsed. Working in PWM mode, the time they stay opened changes all the time in order to control the power supply voltage and not damage the output stage. This is why our amplifiers work from 8V to 18V or even more.

C- Power diodes: Just as in a alternator, they rectify the alternating voltage into DC voltage.

D- Capacitor bank: Provide the capacitance needed to eliminate the pulsating ripple. After the Capacitors the voltage on the SD12kD can be up to 250Vdc.

E- Output FETs: 16 units working in H-bridge mode (means that all voltage RMS from power supply is provided to the load). Being a D class amplifier they work in PWM mode to build a sine shaped signal.

F- Current detection: shunt resistors measure the current from the power supply and send the information to the brain of the amplifier, the 20MHz microprocessor. If a short-circuit occur on the output, the microprocessor shut down the power supply, as an example.

G- Output filter: Being a low-pass filter, it will clean the high-frequency modulating signal from the output stage, allowing only the audio-range signal to pass.

H- Microprocessor and drivers, together they control all the switching devices (FETs) and monitor the protections.

Click to read more...

 

[Johnny Law.Lulz 5,000+ posts]

How is this different from any other amp ?

 

[theMessenjah44 10+ year member]

sexy

 

[Mass Car Audio 10+ year member]

Nice little write up, It should help out some people that want to know how a class d amp processes the signal.

Do you guy's have a test sheet I can see of this amp ? I'm seriously thinking of buying one.

 

[murilo 10+ year member]

Nice little write up, It should help out some people that want to know how a class d amp processes the signal.
Do you guy's have a test sheet I can see of this amp ? I'm seriously thinking of buying one.

Hello, in some time we will have CEA-2006 specs for all models, until then we have only 12.6V and 16V power measurements (12kW and 18kW)

 

[S.B.C. 10+ year member]

Good stuff Murilo

Still waiting on my 2 sd8k's //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Spooney 10+ year member]

its hard to tell from the pic but it doesn't look as if there is much if anything that physically holds the circuit board inside of the heatsink besides the legs of all the fets. it would seem that without the circuit board being mounted down that these amps would be prone to vibration related failure(like legs snapping off of fets). there is a lot of weight on that board . i hope that there is something securing that board down. it would be a shame to hit a pothole and lose an amp.

 

[SPLaudio 5,000+ posts]

look closer between the fets there is screws all the way down both sides of the pcb and i bet some in the middle...