Hi Steve,
Thank you very much for the info. I'll be a lot smarter hanging around you guys for sure. I'll add this to my notes. I won't loose these this time. I did have all this neat stuff in Braille and all neatly in a notebook. I'd sure like to know where that notebook went. I remember I wrote all those notes with a slate and stylus.
73
Scott/N3BYY
On Dec 27, 2011, at 11:37 AM, Steve wrote:
> Scott,
>
> Let's see if I can help here.
>
> Actually, you don't have the formula quite right. You are going to take the
> reciprocal of each value as you add it, so if you connect two 100 microfarad
> capacitors in series, you don't end up with 100 but 50. The formula is 1
> over the value 1/100 plus 1/100 for the two 100 MF caps. Therefore, solving
> you would have 1/100 plus 1/100 or .01 plus .01 which is .02 over 1 equals
> 50. If you were to add another 100 MF capacitor to that series, you would
> end up with .03/100 which would be about 33 microfarads.
>
>
> Another example (and test) of the formula is to use three capacitors, 100
> microfarads, 200 microfarads and 300 microfarads, all in a circuit in
> series. The
> total (series) capacitance would be 1 / (1/100 (.01) + 1/200 (.005) + 1/300
> (.00333)) or about 54.555 microfarads. On your calculator, you would add
> the individual fractions .01 plus .005 plus .00333 which equals .0183333 and
> then put the numerator 1 infront of it to show your results back in
> microfarads which would be 54.555mf..
>
> Of course, you are right, caps in parallel is just a question of adding up
> their values, 100-+200+300 equals 600 microfarads.
>
> Steve, K8SP
>
>
> ----- Original Message -----
> From: "Carolyn Johnson" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, December 26, 2011 7:57 PM
> Subject: Re: Question on time constants
>
>
>> Hi,
>>
>> I know it's terrible, but I took my extra years ago, and all I basically
>> did
>> was remember the answers. A lot of what you learn you aren't going to use.
>> Some of it you will. If you spend a lot of time learning a lot of theory,
>> it
>> really won't help any better with passing. As long as you somewhat
>> understand what the materials are talking about. You'll take years at that
>> rate. This is just my thoughts on it. You decide for yourself how you
>> want
>> to handle your particular situation.
>>
>> Carolyn Kj4vt
>>
>>
>> --------------------------------------------------
>> From: "Scott Howell" <[log in to unmask]>
>> Sent: Monday, December 26, 2011 7:00 PM
>> To: <[log in to unmask]>
>> Subject: Question on time constants
>>
>>> Hi folks,
>>>
>>> I am studying away and hope I can call on you good folks now and then as
>>> =
>>> I try to understand the electronic theory. Ok, so I'll admit that math =
>>> is not my strong point and I'm sure some believe that Hams should know =
>>> this stuff really well and I do agree, but nevertheless I'm not going to
>>> =
>>> just memorize stuff. I don't think that will help me much because I do =
>>> need to understand the "how" and I tend to do better.
>>> So, here is my question.
>>> I'm listening to the Handiham Extra Class lecture and this gent Tony is =
>>> talking about measuring time constance. I get the general idea, but =
>>> where I'm a little confused is with capacitance and resistance as it =
>>> relates to series and parallel circuits.
>>> Of course I should recall from my studies as a Tech and General, but =
>>> that was a pile of years back and I did not put into practice what I =
>>> learned. SHould find some breadboard and stuff to play with which =
>>> probably would help a great deal.
>>> In any case, if you have two capacitors in series equals half the value =
>>> of one capacitor. SO, if I have this correct and you have two 100 micro =
>>> farad caps you would actually have just 100 micro farad caps. In other =
>>> words you add both together and then divide?
>>> For parallel do you just add the two and do not divide?
>>> What about resistors in series? I gather the resistors are doubled, so =
>>> two one hundred KOhm resistors becomes 200KOhm?
>>> Now of course if anyone has any references that I should review that =
>>> would be beneficial to my understanding/recollection, please let me =
>>> know. I unfortunately lost a lot of my notes when I moved and I had =
>>> taken copious notes on the electrical theory and I wish I still had =
>>> those.
>>> If any of this made no sense at all just let me know because I probably =
>>> did not do a good job of explaining things.
>>>
>>> 73
>>> Scott/N3BYY
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