Following on from my very destructive opening of the previous piezo air pump in this video:-
https://www.youtube.com/watch?v=hKsZUuvtylE
I decided to buy another different style for comparison. It's arrived and since we already know what's inside the main pump case from the previous video, let's try it out and then doodle out the schematic of the power supply circuitry.
It's very similar to the first unit we looked at, but replaces the first resistor with a capacitor. It's a bit odd because the other version with three resistors was very simple and possibly more reliable. The combined value of the resistors is pretty much the same anyway.
My theory about the PTC fuse being to protect against capacitor failure or excess electrical noise causing rogue current flow is wrong. It's in series with the capacitor and two resistors that total 24K and would limit fault current in a dead short to 10mA, a third of the fuses rating. The resistors would also just dissipate a worse scenario power of just over a watt each which is well within their rating.
I get the feeling this might be one of many clones with various hashes of the same circuitry.
Someone suggested the theory of the final stage filter being to reduce mains borne signalling noise like data. That's viable, as the piezoelectric disk would act like a loudspeaker and make any noise in the audio range audible.
The disk in the body flexes at 50Hz/60Hz and makes up for the small movement with its area and speed.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
https://www.youtube.com/watch?v=hKsZUuvtylE
I decided to buy another different style for comparison. It's arrived and since we already know what's inside the main pump case from the previous video, let's try it out and then doodle out the schematic of the power supply circuitry.
It's very similar to the first unit we looked at, but replaces the first resistor with a capacitor. It's a bit odd because the other version with three resistors was very simple and possibly more reliable. The combined value of the resistors is pretty much the same anyway.
My theory about the PTC fuse being to protect against capacitor failure or excess electrical noise causing rogue current flow is wrong. It's in series with the capacitor and two resistors that total 24K and would limit fault current in a dead short to 10mA, a third of the fuses rating. The resistors would also just dissipate a worse scenario power of just over a watt each which is well within their rating.
I get the feeling this might be one of many clones with various hashes of the same circuitry.
Someone suggested the theory of the final stage filter being to reduce mains borne signalling noise like data. That's viable, as the piezoelectric disk would act like a loudspeaker and make any noise in the audio range audible.
The disk in the body flexes at 50Hz/60Hz and makes up for the small movement with its area and speed.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Thanks for the demonstration. How is piezo disk is air seal ? Is it just an adhasive or rubber gaske?
For anyone wondering. The bubbles don't add oxygen to the water in an aquarium, it's the bubbles popping on the surface that creates surface agitation which helps the oxygen exchange. In reef aquariums we use power heads to give surface agitation and coral sway
just wanna say that honestly i'm so tired of normal screwdrivers and how i twist my hand around again and again i just now use the electric screwdriver machine thingy whenever i open something that requires a lot of screwing, it's way faster and stronger than my little arms and does the job with the press of a button
Uhh CLIVE, poking a live mains powered circuit with your bare finger and taking thermal photos of same live circuit IN THE DARK, you're gonna give me nightmares! We need you to stay alive. …so, what protection do you use on your bench mains supply?
The acid is probably dissolving the airstone.
Big Clive, I lost my schematic for grid tie mains switch over circuit. Now have an inverter running a motor from battery to start then need to switch over to Genny for run. Can you year down a sola inverter for coffee and cookies?
Man I wanted to see how the pump is constructed not electronics.
To stop foaming add soap from a bar of soap a trace will kill any foaming
Way late to the party – I finally got one of these in North America – Identical power supply. How would you modify this to run on 120V? If mains supply is already the right voltage would a lower value resistor make sense to substitute for current limiting?
Copper what?
I started this video hoping to hear the words "piss flaps" again.
I got a piezo air pump and like on your i can't find where the air is coming IN the pump .. !!! I mean .. there is no spontaneous air generation in this thing .. 😀