I need a lesson in Class D feel free to teach me 😕
seen many of EV subs with SMPS and UCD modules fail
From experience i can tell that often class D amps with SMPS fail from mains Issues .Often poor line filtering and line issues can have catastrophic failure .
Then again many of Class D amplified subs or speakers suffer from construction issues like poor soldering and inefficient vibration proof design
Let us suppose that is no longer an issue if a linear power supply is used
Then the question is what type of other protection is to be used to keep the amp running ?
Thermal protection should not be an issue and a simple circuit measuring temp over heat sink and activating a ventilator should be fine .
How about DC protection ? If amp fails do we have DC in the output ? if any of the mosfets short what will happen ?
How class D amps behave if over driven ? what is the clip like ? can clips of such an amp destroy speakers ? If so is LDR or any other input limiting mandatory ?
Intention is to replace modules of class AB G or H inside pro amps that failed with class D modules so linear PSU stays as was probably one of the heat sinks and the rest of the hardware ..
Opinions please
seen many of EV subs with SMPS and UCD modules fail
From experience i can tell that often class D amps with SMPS fail from mains Issues .Often poor line filtering and line issues can have catastrophic failure .
Then again many of Class D amplified subs or speakers suffer from construction issues like poor soldering and inefficient vibration proof design
Let us suppose that is no longer an issue if a linear power supply is used
Then the question is what type of other protection is to be used to keep the amp running ?
Thermal protection should not be an issue and a simple circuit measuring temp over heat sink and activating a ventilator should be fine .
How about DC protection ? If amp fails do we have DC in the output ? if any of the mosfets short what will happen ?
How class D amps behave if over driven ? what is the clip like ? can clips of such an amp destroy speakers ? If so is LDR or any other input limiting mandatory ?
Intention is to replace modules of class AB G or H inside pro amps that failed with class D modules so linear PSU stays as was probably one of the heat sinks and the rest of the hardware ..
Opinions please
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Class d amps generally clip the same as other classes, but in rare cases, but im not sure, feel free to correct me, the amp can latch, basicly sending dc to output, like shorted outputs, if you turn the amp of and on, it will return to normal operating state.Outputs can fail as shorts, so please use relay dc protection on have a circuit that detects dc on output that turns off the psu, but that is only aplicable to smps . Limiting is kinda needed for PA, as any kind of clipping will destroy the tweeter.
Ok then DC protection IT IS
delay turn on also
Do I expect these amps to produce thumb ? probably yes
Input limiting also
Anything else i am missing ?
delay turn on also
Do I expect these amps to produce thumb ? probably yes
Input limiting also
Anything else i am missing ?
I usually find with class d an output mosfet short blows both mosfets and blows the fuse.
On my irs2092 designs I also have a PIC micro controlling the reset line so I have power on delay and reset held on if VCC drops below 12 volts.
On my irs2092 designs I also have a PIC micro controlling the reset line so I have power on delay and reset held on if VCC drops below 12 volts.
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