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Topic: numerical challenge
Replies: 90   Last Post: Oct 26, 2012 7:41 PM

 Messages: [ Previous | Next ]
 Spehro Pefhany Posts: 25 Registered: 1/25/05
Re: numerical challenge
Posted: Oct 24, 2012 4:44 PM

On Wed, 24 Oct 2012 16:27:02 -0400, Roberto Waltman
<usenet@rwaltman.com> wrote:

>Spehro Pefhany wrote:
>>On Wed, 24 Oct 2012 15:27:12 -0400, Roberto Waltman
>><usenet@rwaltman.com> wrote:
>>

>>>John Larkin wrote:
>>>...
>>>

>>>>This is my first-pass qualifier question.
>>>>
>>>> +10V
>>>> |
>>>> |
>>>> C
>>>>+5V--------------B
>>>> E
>>>> |
>>>> 1K
>>>> |
>>>> gnd
>>>>
>>>>(drawn like a real schematic, on a whiteboard)
>>>>
>>>>What is the base voltage? (one answer: 0.6!)
>>>>What is the emitter voltage?
>>>>What is the collector voltage?
>>>>
>>>>What is the base current?
>>>>What is the emitter current?
>>>>What is the collector current?
>>>>

>>>
>>>Germanium or silicon?
>>>PNP or NPN? ;)
>>>
>>>Roberto Waltman
>>>[Running for cover...]

>>
>>For a (slightly) more advanced test..
>>

>>>> -10V
>>>> |
>>>> 1K
>>>> |
>>>> C
>>>>-5V--------------B NPN
>>>> E
>>>> |
>>>> gnd
>>>>

>One more question: What is the pressure of the magic smoke inside the
>transistor?

If it's a jellybean NPN, the E-B junction is going to be just fine
(typically they break down around 8-9V and are rated for at least 5V),
and the answers are, as JL says, going to be about the same as his
example except for the higher base current due to typically low
reverse beta. But it fits a different visual pattern, being an NPN
with E grounded-- it's probably not obvious that it's a
"collector-follower".

Date Subject Author
10/22/12 Rich Delaney
10/22/12 Phil Hobbs
10/22/12 Rich Delaney
10/23/12 Phil Hobbs
10/23/12 G. Morgan
10/23/12 Phil Hobbs
10/23/12 Robert Macy
10/23/12 Frederick Williams
10/24/12 Robert Macy
10/23/12 G. Morgan
10/24/12 Spehro Pefhany
10/22/12 William Elliot
10/23/12 William Elliot
10/26/12 Rich Delaney
10/22/12 John Larkin
10/23/12 Jeff Liebermann
10/23/12 John Larkin
10/23/12 John Fields
10/23/12 Phil Hobbs
10/23/12 John Larkin
10/23/12 John Fields
10/23/12 John Larkin
10/23/12 John Fields
10/23/12 krw@att.bizzzzzzzzzzzz
10/23/12 John Larkin
10/23/12 krw@att.bizzzzzzzzzzzz
10/24/12 rickman
10/24/12 John Larkin
10/24/12 P E Schoen
10/24/12 John Fields
10/23/12 YD
10/23/12 John Larkin
10/23/12 Jamie
10/23/12 krw@att.bizzzzzzzzzzzz
10/23/12 Sylvia Else
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 Sylvia Else
10/24/12 Robert Baer
10/25/12 krw@att.bizzzzzzzzzzzz
10/24/12 Roberto Waltman
10/24/12 Spehro Pefhany
10/24/12 tm
10/24/12 John Larkin
10/24/12 John Larkin
10/24/12 Roberto Waltman
10/24/12 Spehro Pefhany
10/24/12 Roberto Waltman
10/24/12 John Larkin
10/24/12 Jamie
10/24/12 John Larkin
10/24/12 tm
10/24/12 John Larkin
10/24/12 Jamie
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 tm
10/24/12 John Larkin
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 Jeff Liebermann
10/23/12 Les Cargill
10/23/12 P E Schoen
10/23/12 Nico Coesel
10/23/12 Sylvia Else
10/23/12 Nico Coesel
10/25/12 Rich Delaney
10/23/12 G. Morgan
10/23/12 Tim Williams
10/23/12 Sylvia Else
10/23/12 Sylvia Else
10/23/12 Robert Baer
10/24/12 William Elliot
10/24/12 Butch Malahide
10/24/12 William Elliot
10/24/12 Robert Baer
10/24/12 Robert Baer
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 Butch Malahide
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 Willem
10/24/12 Spehro Pefhany
10/24/12 krw@att.bizzzzzzzzzzzz
10/24/12 Uwe Hercksen
10/24/12 Sylvia Else
10/26/12 Rich Delaney
10/23/12 quasi
10/23/12 Robert Macy
10/23/12 John S
10/23/12 ehsjr
10/23/12 Sylvia Else
10/23/12 Mike Terry
10/23/12 Sylvia Else