Trying to work out where the noise is coming from on this Fosi Tube03.
With gain at maximum, input shorted, I can see a 270Hz and 18kHz spike in the audible band.
cybergibbons
@cybergibbons@infosec.exchange
- 1.3K Followers
- 135 Following
- 460 Posts
That fucking cyclist from Twitter.
So, in an ideal world each capacitor will charge to 20% of 12V....
But we don't live in an ideal world.
At least they should have balancing resistors across them. Other super/ultracapacitor designs I have seen use shunts to make sure they charge equally.
It's specced up to 15V - so that's 3V per capacitor.
The capacitors are unmarked. Are they 3V rated? If so, 15V is dangerously close given the lack of balancing.
Ok, sorry, that's not quite true. There are 3 small SMD capacitors.
C6 is literally going from ground to ground. This is not a sign of quality.
"They possess with the combination of the latest ultracapacitor and lithium battery technologies and thus can completely change the way people use the audio power amplifiers."
Mate, that just looks like 5 cheap ultracapacitors.
Well, it's got 12V in and 12V out. An extruded aluminum case.
That's about it.
No current rating. Just 12V.
What is going on people.
Without further ado, we have another weird piece of Aliexpress gear.
The "2024 New Hades 24V/12V Sonic Scientific Hades DC In 24V, the world's most terrifying energy module"
Is it terrifying? What does it even do?
At 0.8A it has 270mV of ripple at 100Hz.
At 1A, you have another oscillation with the end result being over 2.4V of ripple. Dank.
There are the following on the output side of the regulator:
2*1000uF
2*220uF
1*100nF
Pretty sure that once the ripple goes beyond a certain point, it's game over.
Although it can supply 5V... as soon as you go up to 0.8A and above, it starts to struggle.
It looks like this is combination of two things.
The transformer is a tiny 3.5VA jobby so has terrible regulation, and you get too close for the linear regulator to work.
But also they made some odd choices on capacitors....