100nF vs. 0.1uF

"N pole" means "north-seeking", not "like the north pole of the Earth."

Cheers

Phil Hobbs (Whose Grade 11 physics teacher pointed this out back in 1975.)

Sounds like a combination volume/tone control. ;)

(500M x 3 pF = 1.5 ms, i.e. 100 Hz @ -3 dB)

Cheers

Phil Hobbs

Grin. Well I spent a good part of a day, trying to figure it out. Several compasses (in case one became polarized the wrong way.) Checking the local earth's field in the building, winding my own coil... lots of curling of fingers in right hand rule. You start to question all your assumptions... maybe I never understood the right hand rule in the first place... The good thing about figuring it out for yourself, is you never forget. George H.

You should have seen the look on the guy's face at the parts house when I handed him the old pot, and told him that I needed a new one. ;-)

QWERTY was designed to slow down typists so that it was harder for them make the mechanical bits of typewriters move fast enough to interfere with one another.

The electrical sign convention was arbitrary, but QWERTY was perfectly deliberate.

It's still used in Roman numerals for that purpose.

Where do you think the usage came from?

I only wish! That's one of the bad things about growing old. My presence of mind is better in that at 2 PM I can tell you what I had for lunch now (I tend to ignore unimportant details) but I recently was without email while I relearned what needed to be done to get Eudora to work with authentication. Because of the multiple issues I didn't recognize that the problem was really a bad password. The hosting provider didn't remember any of this either and just said they didn't support perfectly good email clients that are no longer maintained.

In the digital world caps are pretty easy, 100 uF means tantalum, 0.1 uF means ceramic MCC as does 10 nF. There are no others.

I'd better chuck out all my 0.1uF electrolytics then.

NT

Why would you have 0.1 uF electrolytics? Why wouldn't you use a 0.1 uF MLCC?

I use a lot more values than that, even for wholly digital boards. MCUs clock noise gets filtered with self-resonant caps, for instance.

The diode symbol mimics a point-contact device. You find a nice spot on the crystal for the cat whisker, then hit it with a pulse of current. That causes some of the whisker metal to alloy with the substrate, forming a P region.

Cheers

Phil Hobbs