Negative resistance with BJTs

On Sat, 25 Aug 2018 13:51:11 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 08/25/2018 09:38 AM, Tom Del Rosso wrote:
>> Phil Hobbs wrote:
>>> On 08/24/2018 06:47 PM, Tom Del Rosso wrote:
>>>>
>>>> Wasn't he assumed to have had a heart attack since no other cars were
>>>> involved?
>>>
>>> Could be.  Lots of folks survive heart attacks, though.
>> 
>> Sure but you can't help it if it comes while you're driving.  I knew a
>> guy who died that way, who might have survived if it happened in the
>> office.
>
>
>Or in a car with air bags, crumple zones, and a rigid passenger 
>compartment--IOW anything made in the previous 15 years or so.  The old 
>Beetle was a deathtrap.

Especially when you don't wear a seat belt.



-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

dakupoto@gmail.com wrote:
> a four layer diode, consisting of alternate p, n layers acts as a
> negative resistance, and can be realized in practice with a pair
> of NPN and PNP transistors, connected in specific ways. Now, is
> it possible to achive this a series connection of two discrete
> diodes ? I was just thinking about it.
>
   I did this 2-teminal version with one transistor sometime in 2005.
Version 4
SHEET 1 880 680
WIRE 96 64 48 64
WIRE 208 64 96 64
WIRE 304 64 208 64
WIRE 96 96 96 64
WIRE 208 112 208 64
WIRE 304 128 304 64
WIRE -32 144 -32 64
WIRE -32 144 -96 144
WIRE 32 144 -32 144
WIRE 96 208 96 192
WIRE 96 208 -96 208
WIRE 208 208 208 192
WIRE 208 208 96 208
WIRE 304 208 304 192
WIRE 304 208 208 208
FLAG -96 144 In
IOPIN -96 144 In
FLAG -96 208 In
IOPIN -96 208 In
SYMBOL diode 288 128 R0
SYMATTR InstName D1
SYMATTR Value 1N4007
SYMBOL voltage 208 96 R0
WINDOW 3 -47 135 Left 2
SYMATTR InstName Vm
SYMATTR Value Rm=16.3K
SYMBOL npn 32 96 R0
SYMATTR InstName Q1
SYMATTR Value TIP50
SYMBOL res -48 80 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value 3.58K
TEXT -112 176 Left 2 ;Vin
TEXT -88 272 Left 2 ;2-terminal negative resistance\n   used for meter 
protection.\n         (plot Vm VS Vin)

pcdhobbs@gmail.com wrote:
> You can do it with one or more tunnel diodes, but not with ordinary ones because they have no gain.
>
> You can also do it with a single transistor at AC.
>
> Cheers
>
> Phil Hobbs
>
   Also at DC, see my posting in this thread.

> 
> I stuck ferrite beads around the base leads 


put zeh beads on zeh leads

<makolber@yahoo.com> wrote in message 
news:981da395-d8a4-49fd-a5db-99e88ba32a63@googlegroups.com...
>
>>
>> I stuck ferrite beads around the base leads
>
>
> put zeh beads on zeh leads

But I am le tired.

Alright go take a nap ZEN PUT ZE BEADS ON ZE LEADS!!!

(To paraphrase an old video)

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/