"Marshon" wrote in message
...
Hi guys,

Throw me a bone here.......
....What is really starting to bug me is trying to locate a source of
information for alternative parts, especially transistors. I have
acumulated literally hundreds of parts, ...


'suck and see'
Sounds like a new Matel toy...

Simon,
You claim to be no dummy, so... You know what you have, so look at the
application and take what you have that fits the application the best, then
tweek away...er, uh, rather optimize for your choice. The 2N2222 will
probably work on 99% of the projects anyway....

I vote... start suckin'...

--
Steve N, K,9;d, c. i My email has no u's.

Marshon wrote:
Hi guys,

Throw me a bone here.......
Although I only have my UK Foundation licence, I'm not quite a novice
when it comes to circuits. I worked for many years as an IT systems
engineer, can read a schematic, and understand what a circuit is
doing.
What is really starting to bug me is trying to locate a source of
information for alternative parts, especially transistors. I have
acumulated literally hundreds of parts, but I can guarantee that for
any given project I wont have the exact quoted part and will have to
order in a part costing pennies with handling and delivery in pounds.
Maddening to be sure.
Does anyone know of a site that gives a list of alternative or
equivalent parts? As an example, I have hundreds of 2N2222 transistors
but the requirement is for a single BC547 of which I have none. The
datasheets would suggest that the 2N2222 would do the job, but is it
always going to be a 'suck it and see'?

Any advice gratefully received.

Simon (MW3CUR)
When looking at transistors to see if one on hand would be a suitable
sub for one called for in a design the important paramters are the
max voltage ratings (VCBO, VEBO and VCEO), the current gain (Hfe) and
the transfer or cutoff frequency Ft ratings. If the device must handle
any power then look at the power dissipation rating (PD) and max current
ratings (Ic). Be aware that some ratings such as Hfe and Ft are
made under certain operating conditions, IE: a transistor could have a
low current gain at low collector current, but a moderate to high gain
at high currents. That's great for a power amp, but not so good for a
small signal amplifier. If you have a curve tracer (Heath IT-1121 is a
nice inexpensive unit that shows up on ebay from time to time, you need
an external scope for this one) you can identify unknown transistors.

Marshon wrote:
Hi guys,

Throw me a bone here.......
Although I only have my UK Foundation licence, I'm not quite a novice
when it comes to circuits. I worked for many years as an IT systems
engineer, can read a schematic, and understand what a circuit is
doing.
What is really starting to bug me is trying to locate a source of
information for alternative parts, especially transistors. I have
acumulated literally hundreds of parts, but I can guarantee that for
any given project I wont have the exact quoted part and will have to
order in a part costing pennies with handling and delivery in pounds.
Maddening to be sure.
Does anyone know of a site that gives a list of alternative or
equivalent parts? As an example, I have hundreds of 2N2222 transistors
but the requirement is for a single BC547 of which I have none. The
datasheets would suggest that the 2N2222 would do the job, but is it
always going to be a 'suck it and see'?

Any advice gratefully received.

Simon (MW3CUR)
When looking at transistors to see if one on hand would be a suitable
sub for one called for in a design the important paramters are the
max voltage ratings (VCBO, VEBO and VCEO), the current gain (Hfe) and
the transfer or cutoff frequency Ft ratings. If the device must handle
any power then look at the power dissipation rating (PD) and max current
ratings (Ic). Be aware that some ratings such as Hfe and Ft are
made under certain operating conditions, IE: a transistor could have a
low current gain at low collector current, but a moderate to high gain
at high currents. That's great for a power amp, but not so good for a
small signal amplifier. If you have a curve tracer (Heath IT-1121 is a
nice inexpensive unit that shows up on ebay from time to time, you need
an external scope for this one) you can identify unknown transistors.

"Marshon" schreef in bericht
...
Throw me a bone here.......
Sorry....it bounces back off my screen !
Now if you could laugh at it, and if this message reaches this newsgroup, I
will send the list !

Hi guys,

Throw me a bone here.......
Although I only have my UK Foundation licence, I'm not quite a novice
when it comes to circuits. I worked for many years as an IT systems
engineer, can read a schematic, and understand what a circuit is
doing.
What is really starting to bug me is trying to locate a source of
information for alternative parts, especially transistors. I have
acumulated literally hundreds of parts, but I can guarantee that for
any given project I wont have the exact quoted part and will have to
order in a part costing pennies with handling and delivery in pounds.
Maddening to be sure.
Does anyone know of a site that gives a list of alternative or
equivalent parts? As an example, I have hundreds of 2N2222 transistors
but the requirement is for a single BC547 of which I have none. The
datasheets would suggest that the 2N2222 would do the job, but is it
always going to be a 'suck it and see'?

Any advice gratefully received.

Simon (MW3CUR)

"Marshon" schreef in bericht
...
Throw me a bone here.......
Sorry....it bounces back off my screen !
Now if you could laugh at it, and if this message reaches this newsgroup, I
will send the list !

Hi guys,

Throw me a bone here.......
Although I only have my UK Foundation licence, I'm not quite a novice
when it comes to circuits. I worked for many years as an IT systems
engineer, can read a schematic, and understand what a circuit is
doing.
What is really starting to bug me is trying to locate a source of
information for alternative parts, especially transistors. I have
acumulated literally hundreds of parts, but I can guarantee that for
any given project I wont have the exact quoted part and will have to
order in a part costing pennies with handling and delivery in pounds.
Maddening to be sure.
Does anyone know of a site that gives a list of alternative or
equivalent parts? As an example, I have hundreds of 2N2222 transistors
but the requirement is for a single BC547 of which I have none. The
datasheets would suggest that the 2N2222 would do the job, but is it
always going to be a 'suck it and see'?

Any advice gratefully received.

Simon (MW3CUR)

http://w1.859.telia.com/~u85920178/

harry has loads of stuff using 2222/ or 547/s

http://w1.859.telia.com/~u85920178/

harry has loads of stuff using 2222/ or 547/s

On Thu, 29 Apr 2004 11:58:17 +0100, Marshon
wrote:

Thanks to everybody who took the time and effort to reply, and those
who mailed me directly.
Having taken all comments on board, I went for the nearest match to
the original datasheet. Everything works as intended and is up and
running.

Thanks again guys!

Simon (MW3CUR)

On Thu, 29 Apr 2004 11:58:17 +0100, Marshon
wrote:

Thanks to everybody who took the time and effort to reply, and those
who mailed me directly.
Having taken all comments on board, I went for the nearest match to
the original datasheet. Everything works as intended and is up and
running.

Thanks again guys!

Simon (MW3CUR)