Part Sourcing Assistance/Advice Thread

[luvdunhill]

1 minute ago, swt61 said:

I seem to remember some guy laughing at me trying to read resistors when I built Colin's amp. 🙂

Now I have one bionic eye, and can read them fine.

😂

[jamesmking]

8 hours ago, luvdunhill said:

Can anyone recommend a nice portable HD microscope to go with my new far-sightedness for soldering?

I purchased a cheap rebranded scope from amazon one a few years back for smd and pcb inspection It looks identical to this one:

https://amscope.com/collections/student-microscopes-low-power-stereo/products/se420xyz-2l

it works. My only complaints are

1. it does not have a zoom

2. its not trinocular so you can't add a camera look through it at the same time

3. there is no real X and Y adjustment. instead it pivots around which makes moving around a pcb a bit of a pain.

4. because the objective lenses are housed in a rectangular box you cant fit a ring light easily.

5. the objective lenses are not a "standard" mount and that limits you options for different lenses

 

Edited August 30 by jamesmking

[luvdunhill]

14 hours ago, jamesmking said:

I purchased a cheap rebranded scope from amazon one a few years back for smd and pcb inspection It looks identical to this one:

https://amscope.com/collections/student-microscopes-low-power-stereo/products/se420xyz-2l

it works. My only complaints are

1. it does not have a zoom

2. its not trinocular so you can't add a camera look through it at the same time

3. there is no real X and Y adjustment. instead it pivots around which makes moving around a pcb a bit of a pain.

4. because the objective lenses are housed in a rectangular box you cant fit a ring light easily.

5. the objective lenses are not a "standard" mount and that limits you options for different lenses

 

Do you use it for inspection or for assembly?

[jamesmking]

1 hour ago, luvdunhill said:

Do you use it for inspection or for assembly?

bit of both. working distance is ok for either a hot air handle or a soldering iron.

It takes some getting used to since you have a fixed defined viewing circle, you can't move your head and have to organise everything around that. 

I personally found that exact head positioning was very critical to get a good 3d perspective view and this meant I wanted to minimise the number of times I looked up away from the microscope.

Edited August 30 by jamesmking

[bbest]

Hello all!

Now FJPF2145 obsolete on Mouser. But I need to finish my T2. Where it is possible to get or how to replace them?

What you think?

[jamesmking]

3 hours ago, bbest said:

Hello all!

Now FJPF2145 obsolete on Mouser. But I need to finish my T2. Where it is possible to get or how to replace them?

What you think?

FJPF5027OTU seems to be a possibility, seems to have similar specs except lower current rating and the same pinout. 
Hfe of FJPF2145 is 20 - 40 which is the same as the O variant of the 5027

 

[bbest]

2 hours ago, jamesmking said:

FJPF5027OTU seems to be a possibility, seems to have similar specs except lower current rating and the same pinout. 
Hfe of FJPF2145 is 20 - 40 which is the same as the O variant of the 5027

 

all good, but output capasitance 60pF vs 11pF.

Edited October 13 by bbest

[Pars]

Not sure where you are at, but Octopart shows this:

https://octopart.com/search?q=FJPF2145&currency=USD&specs=0

 

[jamesmking]

2 hours ago, bbest said:

all good, but output capasitance 60pF vs 11pF.

farnell in the uk has plenty of stock of the FJPF2145 

https://uk.farnell.com/onsemi/fjpf2145tu/trans-npn-800v-5a-125deg-c-40w/dp/3368628

[Pars]

Looks like you have to buy 250 of them though...

[MLA]

On 10/13/2024 at 4:06 PM, bbest said:

On 10/13/2024 at 1:44 PM, jamesmking said:

 

all good, but output capasitance 60pF vs 11pF

Noted that and am wondering for this application; how much does it matter when used as a current source? I don't know enough of the theory to figure that one out. Help...  ?