I have an FBT MAXX 4a powered speaker which keeps blowing FETS (Q3).
Even with a lamp in series with the AC Line it shorts Q3, D5 & U2
SCHEMATIC HERE
All help would be be most appreciated
Even with a lamp in series with the AC Line it shorts Q3, D5 & U2
SCHEMATIC HERE
All help would be be most appreciated
MOVED FROM CLOSED THREAD IN SOLID STATE FORUM
Hi
It looks like a Class D amplifier output stage.
It's basically a pulse width modulated power switch with a low pass filter.
U2 is a MOSFET driver with high side and low side gate drive.
Check Q4 and then ohm for any low impedance or shorts on the output.
If OK, check with O-scope after disconnecting the 60V drain supply.
EDIT>If the otherside is working, use it for a reference.
Cheers
Hi
It looks like a Class D amplifier output stage.
It's basically a pulse width modulated power switch with a low pass filter.
U2 is a MOSFET driver with high side and low side gate drive.
Check Q4 and then ohm for any low impedance or shorts on the output.
If OK, check with O-scope after disconnecting the 60V drain supply.
EDIT>If the otherside is working, use it for a reference.
Cheers
@infinia Thanks very much for the assistance 🙂
If i am understanding the PWM theory part correctly.
If the amplitude of the audio signal increases or decreases to the mark/space ratio of the waveform, do higher frequency's dictate the amount of on time and lower frequency's the amount of off time on the wave form?
If i am understanding the PWM theory part correctly.
If the amplitude of the audio signal increases or decreases to the mark/space ratio of the waveform, do higher frequency's dictate the amount of on time and lower frequency's the amount of off time on the wave form?
FBT MAXX 6a
Anyone know where I could find a schematic for an FBT MAXX 6a
I tried the 4a but it is a lot different. Any help would be greatly
appreciated.
Thanks 🙂
Anyone know where I could find a schematic for an FBT MAXX 6a
I tried the 4a but it is a lot different. Any help would be greatly
appreciated.
Thanks 🙂
Schematic request.
OK,
Finally got that schematic from FBT send me your email addy if you still need it. 🙂
OK,
Finally got that schematic from FBT send me your email addy if you still need it. 🙂
FBT MAXX 6a Schematic
Hi, if you could e-mail it to me at jt2130@yahoo.com that would be great . Thanks so much, really appreciate it.
Hi, if you could e-mail it to me at jt2130@yahoo.com that would be great . Thanks so much, really appreciate it.
Re: Schematic request.
Packer
Would you be so kind to send a copy to avcadmaster@hotmail.com?
Thanks!
packer said:
Packer
Would you be so kind to send a copy to avcadmaster@hotmail.com?
Thanks!
Posting your email here (or on any open forum) may not be a good idea. Unless you like spam. Better to use the forum PM or email system and not show your email to the spambots.
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