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Sci.Electronics.Basics -> What Germanium PNP transistor do I use?
There are 46 messages in this thread.
You are currently looking at messages 40 to 46.
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Author: EeyoreDate: 09:33 18-03-07
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dingd@ferris.edu wrote:
> Phil Allison wrote:
> >
> > ** So you are refusing to post that schem ?
> >
> > Or explain where it came from ?
>
> *****Oh no, Phil. Not at all. But I have no idea how to post it
> online. Am I supposed to
> scan it in first? Or....?
Yes you would have to scan it or get someone to scan it for you.
You could post it on various sites that host image files for free. I recently
used rapidshare to do just that for example.
Graham
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Author: JoergDate: 18:54 18-03-07
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Michael A. Terrell wrote:
> Joerg wrote:
>
>>Then you must be young. My first car was built in 1969 (I got it around
>>1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
>>components in that car before installing the radio with its Ge
>>transistors: Zilch. Not even a diode.
>
>
>
> US cars were 12 volts a lot earlier than that. My '61 Ford Galaxy was
> 12 VDC. I could dig through my collection of Sams Photofact car radio
> manuals to find the exact dates, but 12 VDC was in wide use when car
> radios were still using vacuum tubes in the US.
>
My father's 1960's Ford Taunus 12M was 6V. This series was somewhat
comparable to the Ford Cortina and probably named after the German
mountain range "Taunus" near Frankfurt. 12M meant 1200cc, 15M was 1500cc
and so on. AFAIR they were built at Ford Motor Company in Cologne, Germany.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: Michael A. TerrellDate: 19:41 18-03-07
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Joerg wrote:
>
> Michael A. Terrell wrote:
> > Joerg wrote:
> >
> >>Then you must be young. My first car was built in 1969 (I got it around
> >>1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
> >>components in that car before installing the radio with its Ge
> >>transistors: Zilch. Not even a diode.
> >
> >
> >
> > US cars were 12 volts a lot earlier than that. My '61 Ford Galaxy was
> > 12 VDC. I could dig through my collection of Sams Photofact car radio
> > manuals to find the exact dates, but 12 VDC was in wide use when car
> > radios were still using vacuum tubes in the US.
> >
>
> My father's 1960's Ford Taunus 12M was 6V. This series was somewhat
> comparable to the Ford Cortina and probably named after the German
> mountain range "Taunus" near Frankfurt. 12M meant 1200cc, 15M was 1500cc
> and so on. AFAIR they were built at Ford Motor Company in Cologne, Germany.
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com
I think that VW was the lone holdout in the switch from 6 to 12
volts. I used to sell and install a lot of 6 V to 12 V converters for
'40s and '50s cars in the early '70s. I repaired a lot of them, when the
moron hooked it up wrong and took out the pair of Germanium power
transistors. There was also a 12 V positive ground to 12 V negative
ground converter for a few oddball models.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
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Author: JoergDate: 19:57 18-03-07
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ian field wrote:
> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
> news:S3_Kh.8197$yW.5299@newssvr11.news.prodigy.net...
>
>>ian field wrote:
>>
>>
>>>"Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
>>>news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
>>>
>>>
>>>
>>>
>>>>As a kid I always laughed when I saw yet another circuit proposal with a
>>>>tunnel diode or a UJT. None of the stores had any, not even the big ones
>>>>in large cities. Looked like someone just had to publish it to show off.
>>>>I built my oscillators with scavenged AF139/239. Or sometimes tubes.
>>>
>>>
>>>A few years ago I had a project published in Television Magazine which
>>>was loosely based on a Programmable Unijunction Transistor (PUT).
>>>
>>>The project met the need for testing opto-couplers that did not offer an
>>>electrical connection to the photo-transistor's base terminal making the
>>>usual "diode" tests impossible, this required a cheap simple and
minimum
>>>parts count pulse generator to drive the LED, granted regular UJTs are
>>>very rare these days so initially I looked at the PUT which is basically
>>>a thyristor with a negative (anode end) gate, my first thought is that an
>>>SCS (silicon controlled switch) - a 4-layer thyristor device with both
>>>gates available would be relatively easy for a TV engineer to obtain, and
>>>failing that, one can be constructed easily with a complementary pair of
>>>small signal transistors.
>>>
>>>However as I looked at the circuit - and the complementary asymmetry of
>>>the 4-layer device, I realised that it was possible to turn the circuit
>>>upside down and use a small TO-92 thyristor to the same effect.
>>>Thyristors of this type are quite common in TV & monitor PSUs - not
least
>>>as safety trip devices, so almost by accident the project became a dual
>>>purpose component tester.
>>
>>
>>I needed something similar at a client. At my lab I have one, a plain old
>>pencil shaped signal injector. But new TSA rules consider that a dangerous
>>items. So.... I made sure the client had some CMOS logic at hand. Took a
>>single Schmitt inverter (but a 74HC14 would also have sufficed), one
>>resistor, one cap and bingo, I had a new pulser.
>>
>>
>>>Don't be too hasty to count out the tunnel diode - according the manual,
>>>the Tek465 scope contains a couple of them.
>>
>>In their haydays those big scopes fell into the category "money is not an
>>objective" :-)
>
>
> Maybe I got the number wrong - its not one of those big "double decker
bus"
> scopes you wheel about on a trolley.
>
No, those are fairly small:
http://www.testequipmentdepot.com/usedequipment/tektronix/oscilloscopes/tek465&465b.
htm
But in their days anything that carried the name Tektronix on the front
panel was big bucks.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: Homer J SimpsonDate: 20:47 18-03-07
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"ian field" <dai.ode@ntlworld.com> wrote in message
news:b5XKh.4642$pP5.1791@newsfe3-gui.ntli.net...
> The 12V auto-electrics were well and truly established in the period I
> remember, and don't forget the first ever transistor radio used a 22-1/2V
> (tube) hearing aid battery - presumably the PP3 hadn't been invented yet.
ISTR 12 volt tube sets with synchronous rectifiers.
--
.
--
.
.
.
.
.
.
.
.
--
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Author: ian fieldDate: 11:12 19-03-07
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"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:BlkLh.8380$yW.5512@newssvr11.news.prodigy.net...
> ian field wrote:
>
>> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
>> news:S3_Kh.8197$yW.5299@newssvr11.news.prodigy.net...
>>
>>>ian field wrote:
>>>
>>>
>>>>"Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
>>>>news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
>>>>
>>>>
>>>>
>>>>
>>>>>As a kid I always laughed when I saw yet another circuit proposal
with
>>>>>a tunnel diode or a UJT. None of the stores had any, not even the
big
>>>>>ones in large cities. Looked like someone just had to publish it to
>>>>>show off. I built my oscillators with scavenged AF139/239. Or
sometimes
>>>>>tubes.
>>>>
>>>>
>>>>A few years ago I had a project published in Television Magazine which
>>>>was loosely based on a Programmable Unijunction Transistor (PUT).
>>>>
>>>>The project met the need for testing opto-couplers that did not offer an
>>>>electrical connection to the photo-transistor's base terminal making the
>>>>usual "diode" tests impossible, this required a cheap simple
and minimum
>>>>parts count pulse generator to drive the LED, granted regular UJTs are
>>>>very rare these days so initially I looked at the PUT which is basically
>>>>a thyristor with a negative (anode end) gate, my first thought is that
>>>>an SCS (silicon controlled switch) - a 4-layer thyristor device with
>>>>both gates available would be relatively easy for a TV engineer to
>>>>obtain, and failing that, one can be constructed easily with a
>>>>complementary pair of small signal transistors.
>>>>
>>>>However as I looked at the circuit - and the complementary asymmetry of
>>>>the 4-layer device, I realised that it was possible to turn the circuit
>>>>upside down and use a small TO-92 thyristor to the same effect.
>>>>Thyristors of this type are quite common in TV & monitor PSUs - not
>>>>least as safety trip devices, so almost by accident the project became a
>>>>dual purpose component tester.
>>>
>>>
>>>I needed something similar at a client. At my lab I have one, a plain old
>>>pencil shaped signal injector. But new TSA rules consider that a
>>>dangerous items. So.... I made sure the client had some CMOS logic at
>>>hand. Took a single Schmitt inverter (but a 74HC14 would also have
>>>sufficed), one resistor, one cap and bingo, I had a new pulser.
>>>
>>>
>>>>Don't be too hasty to count out the tunnel diode - according the manual,
>>>>the Tek465 scope contains a couple of them.
>>>
>>>In their haydays those big scopes fell into the category "money is not
an
>>>objective" :-)
>>
>>
>> Maybe I got the number wrong - its not one of those big "double decker
>> bus" scopes you wheel about on a trolley.
>
> No, those are fairly small:
>
>
http://www.testequipmentdepot.com/usedequipment/tektronix/oscilloscopes/tek465&465b.ht
m
>
> But in their days anything that carried the name Tektronix on the front
> panel was big bucks.
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com
Mine was free - a company I used to repair monitors for decided to downsize
and concentrate on their core business (keyboard refurb), they had a pile of
scopes in the corner which they donated to me. The lowest was a Trio S/T
10Mhz and the best was the 465, all of them had some fault or other, the 465
sometimes "goes to sleep" - it wakes up with a gentle pat on the side so for
the time being I'm content with that rather than mess with the insides if I
can get away with it.
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