What's this please? (Component Advice)

[G7PSK]

STPS20S100CT

That 5 is an S

http://www.alldatasheet.com/datasheet-pdf/pdf/111350/STMICROELECTRONICS/STPS20S100CT.html

Thanks for the reply.
It more a shoddy diode than a schottky diode The PWM is supposed to be rated at 10 amps but this diode gets to hot to touch at 1.4 amps and the writing is duff as well as the 5 is written as an S

[SeanB]

Probably a regular 1A silicon die in a plastic package ( bet the back is poorly moulded and very small as well) sold as the expensive part.

[nelsonro]

Hi, blown my poor rigol dg1022 to hell with a short on the gnd to a live power rail  does anyone know what this is? it's right before the output and 2 pads are connecting the the signal to the output while 2 other pads are connected to gnd, problem is this part has become almost a short to gnd on the signal and as such there is no signal coming out of the rigol, the unit works fine if i just bridge the pads but don't what to risk working without this protection whatever it is

[amyk]

You'll need a clearer picture than that, and perhaps show the component in context on the board.

[SeanB]

I am going to guess it is a common mode RF choke, or a transient suppressor device that clamps overvoltage to ground.

http://www.yuden.co.jp/or/product/category/emisuppression/CM01S600T.html

Is a start to look.

[nelsonro]

more images, the sinal is very clean even without the part, from the side the part looks like it has a cylindrical core glued in place so maybe as SeanB said it's a rf choke?

edit: thinking of cutting the part if it helps

[PA0PBZ]

The better quality picture you posted together with the pcb makes it almost certain it is an output filter, some kind of LC combination circuit.

[nelsonro]

Thanks for the help, gave me a few ideas for new things to put there 

[richcj10]

I have SOT23 package that has the value 01CL on it.
I have the schematic it is in attached.

[nelsonro]

looks like a mosfet or transistor to short 5v to gnd in case of battery over-voltage, better to blow a fuse than a battery i guess. that or someone messed-up the schematic, the datasheet for the battery charger does have a few use cases with mosfets in it but none in the bat pin

[TerraHertz]

With this thing I know what it is, more or less, but can't find data. Only a few incidental mentions of it being used.

It's by Ortel Corp USA. Model PD050-PM   S/N P791.

It's a high bandwidth fiber-optic to photo-diode, with an SMA output connector. I was buying something else from an ebay seller in the USA, and this was only $20 and could go in the same box. The fiber had an obvious kink near the optical connector, and now on arrival, shining a laser through the fiber, yes the glass core was snapped. I cut it off there - still leaving 50cm of fiber on the sensor.

So now I'm also looking for a 2nd hand kit for terminating fiber in these connectors. Actually have been for a while, but not really trying. Here's more motivation.

Would anyone have an old Ortel data book, by any chance? I'd never even heard of them.

[madires]

So now I'm also looking for a 2nd hand kit for terminating fiber in these connectors. Actually have been for a while, but not really trying. Here's more motivation.

The connector at the right seems to be a FC/PC. Is it the same connector as at the back of the diode? A short patch cable should cost about US$ 15-20. I'd choose a SC or LC connector for the non-diode side, since FC/PC is really outdated. And please also check if there's any marking on the current fiber which would indicate if it's single or multimode (something like 9/125 or 50/125).

[TerraHertz]

So now I'm also looking for a 2nd hand kit for terminating fiber in these connectors. Actually have been for a while, but not really trying. Here's more motivation.

The connector at the right seems to be a FC/PC. Is it the same connector as at the back of the diode? A short patch cable should cost about US$ 15-20. I'd choose a SC or LC connector for the non-diode side, since FC/PC is really outdated. And please also check if there's any marking on the current fiber which would indicate if it's single or multimode (something like 9/125 or 50/125).

Unfortunately, the fiber is terminated directly into the sensor. Glued in, with heatshrink cover. It's very likely the fiber is terminated very directly to the actual sensor inside. So, I need to put a new connector on the other end.

I don't know anything about coms fiber standards, connectors, etc. I do have various Cisco routers and stuff, some with fiber connectors (that I've never used.) But mainly I was thinking this might be useful for a project unrelated to coms. The objective would be to examine the light output from something, that might contain components up into the GHz range. So I more need a way to couple the fiber to a lens system, like a C mount small camera lens.

Can you suggest a url for a good review of current fiber connector types, and pros/cons?

There's no marking I can see in the fiber. The sheath seems to be fairly stiff nylon(?) tubing about 1mm dia, with a fiber fairly loose inside the hollow core.

[madires]

Unfortunately, the fiber is terminated directly into the sensor. Glued in, with heatshrink cover. It's very likely the fiber is terminated very directly to the actual sensor inside. So, I need to put a new connector on the other end.

Then the next best thing would be to look for someone with the proper tools to attach a new connector.

Can you suggest a url for a good review of current fiber connector types, and pros/cons?

http://en.wikipedia.org/wiki/Fiber_connectors :-) SC is fine. And if you need something else later on there are back-to-back adapters and patch cables with different connectors at both sides.

There's no marking I can see in the fiber. The sheath seems to be fairly stiff nylon(?) tubing about 1mm dia, with a fiber fairly loose inside the hollow core.

That's a pity because the marking would tell us roughly which transmission windows are to be expected.

[TerraHertz]

http://en.wikipedia.org/wiki/Fiber_connectors :-) SC is fine. And if you need something else later on there are back-to-back adapters and patch cables with different connectors at both sides.

Ha ha ha... no matter *how* many times I tell myself to search first, ask 2nd, I still get caught doing that sometimes. Old pre-internet habit. Anyway, thanks.

There's no marking I can see in the fiber. The sheath seems to be fairly stiff nylon(?) tubing about 1mm dia, with a fiber fairly loose inside the hollow core.

That's a pity because the marking would tell us roughly which transmission windows are to be expected.

Ah. That's something that didn't occur to me. I just presumed the transmission spectra would be flat. I would like to find out. Hopefully when (if) I find the data for this, it will include that info. If not, I have a 20cm length of the fiber with a connector on one end. Could put a connector on the other end too. But would a 20cm length be enough to do transmission spectra measurement? Perhaps not.

I don't suppose it's possible to tell, by looking at the fiber under a microscope?

Well, all this should wait till I find the data. I can probably determine if the sensor is working, even before putting a connector on the free end of the fiber.
It's nice that it has a male SMA. It can mount directly on an input of my HP 54121T 20GHz scope. Assuming it doesn't need a bias supply, which it might.

[madires]

I don't suppose it's possible to tell, by looking at the fiber under a microscope?

If you got a ruler with a µm scale :-) But you could check the relative difference between the core and the cladding. Multimode has usualy a 50µm (sometimes 62.5) core and a 125µm cladding (hence the marking 50/125) . Singlemode is 9/125 typically.

[TerraHertz]

If you got a ruler with a µm scale :-)

Heh. It's called a micrometer.  I do.

But you could check the relative difference between the core and the cladding. Multimode has usualy a 50µm (sometimes 62.5) core and a 125µm cladding (hence the marking 50/125) . Singlemode is 9/125 typically.

After slitting a bit of the outer nylon sheath, then slitting off a few mm of the next sheath under magnification (it's some kind of silicone stuff I think, quite soft), the fiber is indeed 0.125mm (125um).  But it seems to be glass, and I can't think of any way to determine the size of the core. The core and cladding are just two different density glasses melded together, right?

[SeanB]

Technically it is an outer cladding cylinder over an inner rod then fused together and drawn into a fibre, but yes it is one single unit even though the composition of the glass changes between outside and centre.

[mswhin63]

Hi, Can anyone tell me what kind of sensor it is that is in the photo please. Just cleaning out some parts.

[JoannaK]

Help!

I'm in a middle of repairing an Scooter CDI unit (from Hyosung SF50) and while de-potting/examining the system I found a 3 legged part with following desriptions I think is faulty.

- 3 legs, black and looks like regular to-92 transistor.  (thus no picture)
- At the component, there are 2 lines of markings:   P4M   and   3X
- PCB Silkscreen has making   Q5  ... (so most likely transistor, perhaps Fet?)
- All 3 legs are shorted together internallty (2ohms or less.. ) 

This part is located next of 2N3904 transistor and NEC 2P4M thyristor which are connected together and to best of my knowleldge do the capasitor discharge that causes the ingnition to fire.

Totally unrelated, but this cdi unit has embedded AT90S2313 -4PI microcontroller and I located In circuit programming header (unpopopulated, though) so it might be possible to read back the code/data of those CDI module.

[PA0PBZ]

- At the component, there are 2 lines of markings:   P4M   and   3X
This part is located next of 2N3904 transistor and NEC 2P4M thyristor which are connected together and to best of my knowleldge do the capasitor discharge that causes the ingnition to fire.

Coincidence?

[JoannaK]

It may indeed well be, that the unknown part is/was NEC made. Unfortunately NEC sold that part of the company to Renesas some years ago.

Also these parts are so old, that the best bet would be searching the Obsolete-bin, but so far no luck
http://www.renesas.eu/req/obsolete_search.do?event=discontinuedSearch

[PA0PBZ]

This link says it is a 500V 0.4A Thyristor: http://articulo.mercadolibre.cl/MLC-412226324-p4m-p4m-03-03p4m-thyristor-tiristor-scr-to-92-500v-04a-_JM

[JoannaK]

Thank you.

As far as I know it's quite common for thyristors to fail to total short (essnetially fuse together permanently), and the location/wiring suppports the idea of second SCR ..

There seems to be quite a many similar high-volt thyristors available at to-92 case. And of those that I have checked, even pinout compatible. So I'll go and purchase some BT149G or MCR100-6G tomorrow (assuming I find some at local shop) and will try if that was the problem.

(edit)
 I attached pic of the part, it really looks like one PA0PBZ linked. )
PS: I know.. I shoudl take pics with real camera and not try to *** up with a phone.

[Alexei.Polkhanov]

eBay?    I don't trust that site for accuracy. I'm planning to make a decent PSU from parts i have in a basement or in my mind, my cardboard box transformer PSU burned out the compact bridge rectifier again dispite the forced cooling of the fan while testing a small schematic, 25A should be fair enough, but 250A is better chances to survive accidental shortcuts. Although it is similar or same as the one in that link._

?2-25 - is a diode 25A, digit that follows it mean voltage class. for example ?2-25-4 means 25A, 400V. Letter '?' means D in Cyrillic for diode. I was 10 years old 30 years ago - they were already history back then

Model: ?2-25-4
Type: power, rectifier
Max reverse voltage(V):400
Max forward current(?): 25
Anode:
Cathode: body
Thread: ?12
Max temp: 130°C
(Voltage drop?) Vfm ?1.8V
Max reverse current Irm ?18mA
?30mm