I asked AI “ why do pillow type caps excist ?”

[Retroman839]

And the answer i got was

Pillow type caps," commonly known as nightcaps or sleep bonnets, exist primarily to protect your hair overnight, regulate body temperature, and reduce scalp

🤣🤣🤣🤣🤣

 

[John Bennett]

It's like it's too scared to ask you what the hell you're on about

 

[big10p]

Garbage in. Garbage out. Lol

 

[BigP_BigP]

Garbage in. Garbage out. Lol

LOL

They are also sometimes called Jellybean caps here. I wonder what it would say if you asked it that?

I am no AI but I would say its likely just because thats how someone thought to originally build them and they have hung around because have better high-frequency performance and can hold tight tolerances across a wider range of temperatures than some construction types.

 

[Fantazia2]

When you ask it clearly.

"Pillow type" capacitors commonly refer to metallized polypropylene (PP) film capacitors, which are often housed in rectangular, flat, or slightly rounded plastic cases. These components are widely used in AC motor run, power electronics, and lighting applications due to their high stability, low losses, and "self-healing" properties. [1, 2, 3, 4, 5]
Here are the key characteristics and types of these capacitors based on typical industry applications:

Key Characteristics of Film "Pillow" Capacitors

• Dielectric Material: Usually Polypropylene (PP) or Polyester (PET).
• Self-Healing: If a breakdown occurs, the metallized layer evaporates around the fault, preventing short circuits.
• Structure: Non-polarized (suitable for AC), featuring low ESR (Equivalent Series Resistance) and low inductance.
• Voltage Range: Often rated for high AC voltages (e.g., 450V AC).
• Physical Form: Typically rectangular, leaded or with faston terminals, providing a compact, stable, and durable component. [1, 2, 3, 4, 5, 6]

Common Applications

• Motor Run: Used in HVAC, washing machines, and pumps.
• Lighting: Fluorescent light ballasts.
• Power Electronics: Snubber capacitors, resonant circuits, and switching power supplies.
• Audio: High-quality loudspeaker crossover networks. [1, 2, 3, 4, 5]

Popular Examples & Specifications

• Ducati Energia 4.16.10 Series: Common 5μF or higher PP film motor run capacitors, rated for 450V AC with self-healing.
• RS PRO MRP440 Series: Polypropylene film capacitor (5 μF, 440V AC) for screw mounting.
• Dayton Audio DMPC Capacitors: Metallized polypropylene capacitors specifically designed for audio crossovers. [1, 2, 3, 4, 5]

Note: In some online contexts, "spicy pillow" is slang for a swollen, failed lithium-ion battery, but this is different from a "pillow type" capacitor component. [1]
To help you find the right component, are you looking for a specific capacitance (μF), voltage rating, or application (like motor run or audio)?

 

[Retroman839]

It's like it's too scared to ask you what the hell you're on about

I was just happy it was not able to read my brain yet 🤣

 

[Retroman839]

When you ask it clearly.

"Pillow type" capacitors commonly refer to metallized polypropylene (PP) film capacitors, which are often housed in rectangular, flat, or slightly rounded plastic cases. These components are widely used in AC motor run, power electronics, and lighting applications due to their high stability, low losses, and "self-healing" properties. [1, 2, 3, 4, 5]
Here are the key characteristics and types of these capacitors based on typical industry applications:

Key Characteristics of Film "Pillow" Capacitors

• Dielectric Material: Usually Polypropylene (PP) or Polyester (PET).
• Self-Healing: If a breakdown occurs, the metallized layer evaporates around the fault, preventing short circuits.
• Structure: Non-polarized (suitable for AC), featuring low ESR (Equivalent Series Resistance) and low inductance.
• Voltage Range: Often rated for high AC voltages (e.g., 450V AC).
• Physical Form: Typically rectangular, leaded or with faston terminals, providing a compact, stable, and durable component. [1, 2, 3, 4, 5, 6]

Common Applications

• Motor Run: Used in HVAC, washing machines, and pumps.
• Lighting: Fluorescent light ballasts.
• Power Electronics: Snubber capacitors, resonant circuits, and switching power supplies.
• Audio: High-quality loudspeaker crossover networks. [1, 2, 3, 4, 5]

Popular Examples & Specifications

• Ducati Energia 4.16.10 Series: Common 5μF or higher PP film motor run capacitors, rated for 450V AC with self-healing.
• RS PRO MRP440 Series: Polypropylene film capacitor (5 μF, 440V AC) for screw mounting.
• Dayton Audio DMPC Capacitors: Metallized polypropylene capacitors specifically designed for audio crossovers. [1, 2, 3, 4, 5]

Note: In some online contexts, "spicy pillow" is slang for a swollen, failed lithium-ion battery, but this is different from a "pillow type" capacitor component. [1]
To help you find the right component, are you looking for a specific capacitance (μF), voltage rating, or application (like motor run or audio)?

Self healing —/
Like wow..
Now that’s impressive

Spicy pillow !
Wow …. How far down this rabbit hole we going !…

Thanks for the explanations.

They sound better than the common cylinder type ..

Is it production cost that makes the cylinder type the common ?

 

[Bods]

I was trying to get a straight answer on a dumb video my brother sent me trying to show me how much difference putting some foil behind ya radiator makes as well as a 4mm sheet of perspex over the front of his bay window, he was outside measuring his wall with infrared thermometer and said here you can see where the radiator is which is under where the bay window sticks out above, flat wall underneath is warmer than the wall each side, it was about 1 degree warmer under the bay because that's where the radiator is and even with his foil its still loosing more heat through the inside blocks, the foil, the cavity wall insulation and outside bricks

My reply was it's probably warmer because under the bay it's probably trapping the heat in slightly more than each side being open to elements but I just got a load of abuse back from him calling me an idiot this was in Feb when it was quite cold
So when I got home from work I measured my outside wall, I don't have foil on the wall behind radiator and it's in front of a bay window just like his with flat wall under it and I got exactly same results bricks same temprature with it being about 1 degree warmer and the higher upto the bottom of bay it was even warmer, the main proof he was talking nonsense is my heating hadn't been on all day so no heat loss at all

Couldn't get a straight answer from AI, banging on about all sorts of crap about heat loss, thermal bridging, solar thermal lag,
Bay windows are common sources of heat loss in older homes because they often lack proper insulation within the wall or floor cavity underneath them
saying the wall under bay doesn't have insulation,well it does, the lack of insulation top and bottom of bay etc

Even when pointed out it was night time, no heating on, cavity wall insulation present, flat wall still getting nonsense and finally got a bit of a straight answer

Reduced Airflow and Exposure
Jutting out means the bay area is more exposed to cold nighttime winds. However, this same exposure can create stagnant air pockets (microclimates) sheltered from the wind. Combined with heat escaping from the home, these sheltered corners hold onto radiated heat slightly longer than a flat wall exposed to direct wind

I gave in

 

[BigP_BigP]

Self healing —/
Like wow..
Now that’s impressive

Spicy pillow !
Wow …. How far down this rabbit hole we going !…

Thanks for the explanations.

They sound better than the common cylinder type ..

Is it production cost that makes the cylinder type the common ?

They are highly suited for some applications like filtering high frequency noise before an IC and not as good at others like a smoothing Cap on a PSU. So its horses for courses.

 

[John Bennett]

Self healing —/
Like wow..
Now that’s impressive


They sound better than the common cylinder type ..

Is it production cost that makes the cylinder type the common ?

If by 'cylinder', you mean electrolytics - the main reason they're everywhere is the capacity is much, much higher than the other types of capacitors. Sadly they do have their downsides, especially robustness, so in some industries/applications, you try to get away with substituting lots of the other types if you can.

I don't know how much of a big deal the concept of self-healing is - tantalums are supposed to self-heal but they can certainly let out the smoke when they go!

 

[Retroman839]

If by 'cylinder', you mean electrolytics - the main reason they're everywhere is the capacity is much, much higher than the other types of capacitors. Sadly they do have their downsides, especially robustness, so in some industries/applications, you try to get away with substituting lots of the other types if you can.

I don't know how much of a big deal the concept of self-healing is - tantalums are supposed to self-heal but they can certainly let out the smoke when they go!

Haha ..

Yeh I had an alectrolyite flare up and burn down infront of me the other week ..

The appliance still works
Same as my inductance hob..

That was spitting little
Smoke rockets out had that terible acrid smell of electronics burning …
But still works as normal.

Don’t worry I have smoke alarms all over house interlinked ..

I thought it wouldn’t work anymore but it does só I continue to use it for now .