Random Component Questions

[Cotowar]

Okay, so I was in Radio Shack today, and I came across several variations of the same component. I was wondering what the difference between them is. For example,

Ceramic Disc Capacitor vs. Electrolytic Capacitor
Surface mount vs pins
They also had capacitors with a lead coming out each end and some with both leads on the same end. What does it matter?

Different types of resistors, I can't remember exactly the name of them.

They had these rectangle shaped ones, but they were the same resistance as the tiny little common kinds. The rectangle ones were white, and the little ones had the bands on them. What's the difference?

Also, how do they make the resistors so resistive without making them physically larger? I mean, if you have 3 purple bands and a gold band, thats a heck of a lot bigger than a 1 Ω resistor. How do they make them so different without changing the size?

Whats the difference between a MOSFET, PNP, and NPN? Couldn't you interchange the PNP and NPN if you switched the connecting circuitry around? I don't know, so please don't get irritated by the level of simplicity of these questions.

Oh, and what the heck is "magnet wire"? How is it different from regular stranded or solid wire? It doesn't look any different...

That's about it for now, I'll post more dumb questions later as I come up with them.

 

[bacterozoid]

Okay, so I was in Radio Shack today, and I came across several variations of the same component. I was wondering what the difference between them is. For example,

Ceramic Disc Capacitor vs. Electrolytic Capacitor
-Electrolytics are polarized (put them in backwards and they can explode) and have higher capicatances than ceramics. Ceramics are your lower values and have some different properties in general.

See:
Ceramic capacitor - Wikipedia, the free encyclopedia
Electrolytic capacitor - Wikipedia, the free encyclopedia


Surface mount vs pins
They also had capacitors with a lead coming out each end and some with both leads on the same end. What does it matter?
I don't know that it does. The ones with leads on both ends are called axial. The other ones are radial.

Link: Electronics 2000 | Capacitor Code Calculator

Different types of resistors, I can't remember exactly the name of them.

They had these rectangle shaped ones, but they were the same resistance as the tiny little common kinds. The rectangle ones were white, and the little ones had the bands on them. What's the difference?
The big rectangle ones are high power resistors. If you have a lot of power (watts), you need either a blue resistor or one of the larger rectangle ones. I believe those are like 1Watt. If you don't have a high power resistor and you need one, it's likely to just get really hot and burn up. Usually you don't need these. The bands on the smaller resistors tell you the resistance value.

Link: Graphical Resistance Calculator

Also, how do they make the resistors so resistive without making them physically larger? I mean, if you have 3 purple bands and a gold band, thats a heck of a lot bigger than a 1 Ω resistor. How do they make them so different without changing the size?
Magic, I guess. They are just made differently - the materials have different properties which conduct current better or worse

Whats the difference between a MOSFET, PNP, and NPN? Couldn't you interchange the PNP and NPN if you switched the connecting circuitry around? I don't know, so please don't get irritated by the level of simplicity of these questions.
Yes, you can use PNPs and NPNs in the same circuits if you just switch up your supplies and a couple other things. You can even take entire courses dedicated to these guys and do that all you want! You have to basic transistor classes: FET and BJT. Honestly, I forget the major differences and applications since I'm not a big analog guy. But don't fear, I know there are plenty of analog gurus out there that will be more than happy to answer this one.

Oh, and what the heck is "magnet wire"? How is it different from regular stranded or solid wire? It doesn't look any different...

That's about it for now, I'll post more dumb questions later as I come up with them.

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Remember, you can always Google a lot of this stuff if you have quick questions. Happy to help though! (Oh, and if you're going to buy a lot of parts, try not to buy them at radio shack or equivalent. You'll overpay. Design your circuit and get things from another source if you can...if the shipping works out well you'll save a lot of money in the long run.

 

[Cotowar]

Yea, I was just looking around at what all was out there. I don't really need a lot of stuff right now, at least for the ideas I have on paper. I would rather pay $2 for a part than pay $0.40 on line and add $10 in shipping. I do know what you mean though, thats why best buy and circuit city have lost my business to newegg and tigerdirect.

 

[stevez]

Two books in my collection that would help you with questions such as these:

ARRL Handbook for Radio Amateurs - they publish one every year.

Practical Electronics for Inventors by Paul Scherz - I am sure there are other books.

Magnet wire is usually solid copper with a varnish or plastic coating - used for winding magnets, motors, inductors.

 

[Hero999]

Radial, axial and surface mount are just different package types for capacitors and other components.

The resistance value doesn't affect the size of a resistor because the resistance of different materials varies hugly. Try measuring the resistance of a 1cm³ cube of coper and a 1cm³ of plastic with a multimeter and you'll find that one reads 0Ω and the other reads infinity which means >20,000,000Ω in the case with most multimeters. As bacterozoid says they just use different materials.