I was looking at some of the IRS2092S amps and ran across this one with AC input for power on and speaker protection. This seems unnecessary to require 110/220 for amp power on just to prevent speaker power on and off thump.
Has anyone tested these? Maybe someone could explain the benefits of this design.
Has anyone tested these? Maybe someone could explain the benefits of this design.
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Sure, they could have built the speaker protection function to require another external power supply. They incorporated the power supply into the module for convenience I guess. Up to you to decide if you think that's a good idea or not.
I guess I've just never seen a power amp with a direct ac line from the psu like this before. Seems like a separate dc input would work as well?
It really doesn't look like that part of the circuit has proper clearance/creepage for mains voltage. You might be able to bypass that onboard supply and use an external one once you figure out what voltage it outputs.
There's no onboard PSU on that module - if there was, why would you need a separate PSU as well? (not to mention that there are no PSU parts on the amplifier PCB). Pretty sure that they have just added a mains sense circuit for the speaker protection circuit - because unlike most of these small amp modules you can actually see a speaker protection relay on this one.
OK so you're saying they're are using something like this for the sense circuit (speaker protection)?
https://www.instructables.com/AC-Mains-Detector-Circuit/
https://www.instructables.com/AC-Mains-Detector-Circuit/
Yes, although the exact circuit isn't known of course. Note also that you can quite clearly see a 4-pin DIP component (usually an optocoupler) next to the red input.
There's obvious components for a buck converter there, but maybe that's just for powering the fan? I still find the lack of mains clearance to other components questionable.
Those components are a) tiny and b) right next to the fan power connector - evidence enough for me 😀
With AC mains terminal
https://www.amazon.com/IRS2092S-Power-Amplifier-Digital-Channel/dp/B0BSH2FJQD
Without AC mains terminal
https://www.amazon.com/IRS2092S-Digital-Amplifier-Singel-Channel/dp/B0C7Z557B1
https://www.amazon.com/IRS2092S-Power-Amplifier-Digital-Channel/dp/B0BSH2FJQD
Without AC mains terminal
https://www.amazon.com/IRS2092S-Digital-Amplifier-Singel-Channel/dp/B0C7Z557B1