I want to know how these amplifiers work
The switching part of these amplifiers is digital and I want to know more about them
If you have a full service manual for one of the stetsom amplifiers, please share
Thanks
The switching part of these amplifiers is digital and I want to know more about them
If you have a full service manual for one of the stetsom amplifiers, please share
Thanks
Contrary to popular belief, these "Brazilian" amps work very simply.
Everything is managed by an IC suitably programmed to do 2 basic operations, PWM management and protections.
Usually an IC is used with a clock frequency generated by an external crystal and through internal dividers a frequency (which varies according to the battery voltage) is generated which is used to MANAGE the drivers (IR4427?) That operate the power mosfets.
Contrary to popular belief, the power supply oscillates at a rather normal frequency, perhaps only slightly higher.
Through an internal divider, the IC generates a frequency 4 times larger than that of the power supply, which is used as a carrier frequency to be mixed together with the input audio signal, so as to create the signal suitable for class D (the " mixing "is carried out by a comparator circuit on board) which is sent to 2 phase reversers.
The two reversers will send the signals suitable for the power drivers (in many STETSOM amplifiers IR2010S are used, but a different driver must be used based on the rail voltage) which will directly drive the output mosfets.
There will be 2 output stages, each with the phase inverted 180 degrees with respect to the other, these will be used in full bridge, exactly as in the 2 channel amplifiers used in bridge, but without "central node" or "common ground".
Other protection systems are implemented externally and when they are activated, a certain signal is sent to some specific pins of the IC I mentioned at the beginning, which will turn off the entire amplifier signaling the protection by means of a specific LED, turning it on or making it flash according to a code defined by the manufacturer.
Very important thing.
Since these amplifiers work in FULL BRIDGE mode, the rail voltage is single (not dual as in traditional amplifiers) and -RAIL corresponds to BATTERY GND.
This is because a central node is not necessary.
Are you have same project?(mcu smps)
I made a simple board with attiny13a but pwm feequency fixed at about 500hz and i can't change it's frequency
Do you have idea to change frequency?(40khz per rail at 48%dtc)
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Do you know what ic stetsom used for sd250.2d for class D?
I can't find this amplifier's service manual
I can't find this amplifier's service manual