Help identifying components

[Vertigo]

I've been looking inside my Demeter and working on a schematic and layout. There are a few components that I'm not familiar with and I'm hoping to get help identifying them.

I have no idea what these are.

3564B3A9-09E0-4409-81F7-0E569600A9EC_1_201_a.jpeg

These are both the same thing, taken from different angles. I think PN4393 is a JFET, but I can't sort out what the 025 and 51 markings mean on the top.

1C73E0D3-45F4-4817-B7BB-8F0BE3DB8427_1_105_c.jpeg

250E1F13-D09B-416D-A02B-5FC784D81C4F_1_105_c.jpeg

Is this a 270pF capacitor? If so, can you tell what type. You can see the edge of the foil and it looks like it's encased in clear epoxy.

62EF7E03-4445-4AFD-B3E7-A52471060269_1_105_c.jpeg

I don't have the slightest idea what this is either. It appears to have been cast, looks like cast iron to me and it is not magnetic (despite looking like a magnet to me)

898A8448-2786-4649-A1F2-7840B26A4328_1_105_c.jpeg

[Vertigo]

Google isn't giving me any hits on this one either.

680DDA82-09F5-450E-9D32-9A2D2FE50D6F_1_105_c.jpeg

Channel switching FET?

6591FF24-C70C-4491-920C-A98FB5B46B9F_1_105_c.jpeg

[pompeiisneaks]

So that's a lot of components.

first pic are diodes, possibly shottke but wouldn't know for sure without more detail.

Second pic, a couple of transistors of some kind, but to know you'd need to see the front flat face of them and lookup the part number, could be jfets, mosfets, pnp/npn transistors, etc.

Third pic, if the same transistors, says they're PN4393 which are N-channel JFET's https://www.mouser.com/datasheet/2/68/p ... 541430.pdf

The next silver tube thing loosk to me like a capacitor, but I can't be sure.

Next is a full bridge rectifier in a brick, the ~ are the AC inputs and - and + are your outputs.

The next with the B60S and + seems something I've not seen, but COULD be another rectifier bridge but not sure.

Next you've got an opto isolator next to another transistor, and then to the right a J176b P channel JFET https://www.mouser.com/ProductDetail/ON ... P7Dw%3D%3D

Hope that helps. Almost always googling the letter/number combo on the front and 'datasheet' will give you data, that weird round one gives me nothing.

~Phil

[thetragichero]

270j that's a 27pf capacitor
b60s looks like a diode to me. my guess would be to half wave rectify something since it's pretty hefty
what are we looking to do to this or is this just for esses and gees?

[TUBEDUDE]

the capacitor is styrene I believe.
And the round B60 component is a bridge rectifier also.

[Vertigo]

270j that's a 27pf capacitor
b60s looks like a diode to me. my guess would be to half wave rectify something since it's pretty hefty
what are we looking to do to this or is this just for esses and gees?

Just for esses and gees.

Everyone is experiencing this pandemic in their own way. I've been diving into guitars and amps to protect my sanity. I make ultra high end one-off custom titanium bicycles for a living and my business has slowed down considerably. My shop is at home but with my 8y/o and 11y/o home all the time and doing "distance learning" I don't have many productive hours available anyway and I also don't get to sneak away twice week for a couple hours of mountain biking. My wife is a teacher, which is great since she still has a job, but she's also working 70 hrs/week trying to get a handle on all the educational platforms, communicating with parents, creating lesson plans etc...

I've always been intimidated by electronics, but it's starting to sink in and is a great way to get some much needed time apart from my family while inducing brain cramps.

Thanks for the help everyone!

[martin manning]

I make ultra high end one-off custom titanium bicycles for a living and my business has slowed down considerably.

I thought the pandemic had sparked a bike boomlet?

Here's something you can get for cheap that is actually quite useful for testing and identifying components: https://www.amazon.com/Multifunction-tr ... 149&sr=8-2 Your daughter could probably have some fun with it too.

[Vertigo]

I make ultra high end one-off custom titanium bicycles for a living and my business has slowed down considerably.

I thought the pandemic had sparked a bike boomlet?

Here's something you can get for cheap that is actually quite useful for testing and identifying components: https://www.amazon.com/Multifunction-tr ... 149&sr=8-2 Your daughter could probably have some fun with it too.

Thanks! We'll take a look at that and save it for when the rain settles in (in a few weeks). My 8 y/o will love it!

The pandemic did kick off a boom and it has affected different parts of the industry in different ways. Early on when people realized they were going to be stuck at home but before they realized how their finances were going to be affected, the entire industry saw a boom across all price points. I'm sure the injection of $$ into the hands of regular folks helped that along. My orders went up a tick (I only do 1-2 bikes per month anyway) and the tire kicking spiked considerably. Over the course of the past six months, the low and mid market stayed strong...people have more time to ride and EVERYONE wants their 30 y/o bike to be serviced. The top end has slowed quite a bit, I'm hearing this from a lot of peers too. Predictably, there's a supply issue that has affected everyone. I only sell complete bikes (a lot of other frame builders are happy to sell just frames) for a few reasons, but the supply problems have hit me hard, especially from my main drivetrain and brake supplier. I waited months for some small parts to complete a top tier build back in June and just lost a sale because the stock levels won't be replenished until nearly December for the components I needed (and that date will likely slide further away as we get nearer to it.) Anyhow, big impact to cash flow but it's OK because we live very modestly specifically so I could always make a choice to put the needs of our kids above all else. It's not easy, I need some solitude and this is a good way to get it for the time being.

[martin manning]

Interesting. I am a roadie since the early '70's, and used to hang out on the frame list quite a bit.

[Ten Over]

Is this a 270pF capacitor? If so, can you tell what type. You can see the edge of the foil and it looks like it's encased in clear epoxy.

That is a 270pF capacitor composed of polystyrene dielectric fused to foil. I still have some of these on hand that I bought from Mouser in the nineties. Amazingly enough, they are still available from Mouser and the part number is still 23PS127.

[Vertigo]

Is this a 270pF capacitor? If so, can you tell what type. You can see the edge of the foil and it looks like it's encased in clear epoxy.

That is a 270pF capacitor composed of polystyrene dielectric fused to foil. I still have some of these on hand that I bought from Mouser in the nineties. Amazingly enough, they are still available from Mouser and the part number is still 23PS127.

Thank you!

[Vertigo]

Interesting. I am a roadie since the early '70's, and used to hang out on the frame list quite a bit.

Do you have good ride options where you are?

"gravel" bikes are the hot thing for curly bar bikes right now but the industry powers are loathe to admit that they're essentially the same as mountain bikes from the late 80's but with 700C wheels. For folks who like to ride drop bar bikes, they're pretty great and from my perspective they've also been a very good vehicle to get aging buyers to set aside some ego and to get properly fit on a bicycle with a reach and handlebar height that matches how their body works rather than the "slam that stem" mentality that leaves them eternally uncomfortable. They also happen to be super comfortable on the road with fatter, lower pressure tires and less aggressive handling characteristics. The past decade has seen some impressive technology changes in bicycles, even if you ignore e-Bikes.

[martin manning]

I have lots of good pavement available, urban environment one way, and (after a half-dozen miles) low-traffic country roads the other. I've seen the gravel bike thing catching on. Seems kind of like a ruggedized rando bike, no?

[Vertigo]

I have lots of good pavement available, urban environment one way, and (after a half-dozen miles) low-traffic country roads the other. I've seen the gravel bike thing catching on. Seems kind of like a ruggedized rando bike, no?

Similar in fit, but not handling.

Traditionally, randonee/brevet/audax bikes were made so they could carry weight over the fork, sometimes just a bar bag, sometimes panniers or a small porteur style rack. Because of this they were built with somewhat steep head angles in the 73/74° range and the forks were built with more rake/offset. This made a bike with less "trail" than is typical which also has less "wheel flop". It reduces the effort required to steer the bike when you have both more weight over the front wheel and an added swing weight which reduces the immediacy of your steering input. These types of bikes typically are well mannered with a loaded front wheel, but less so when the load is taken off (low trail bikes in general tend to get squirrely when the front end isn't loaded.) they're also often difficult to ride hands free.

Gravel bikes generally will have a slacker head tube angle, less rake in the fork and will end up with a longer wheel base and more trail. All of those factors make for a MUCH more stable ride at speed and also decreases the tendency for the front end to dig in loose conditions. Tweaking the front-center and wheelbase can also gain some clearance from toe overlap which can be an issue for anyone on a bike smaller than about a 56cm. If you've ever dug into geometry charts and looked at the smaller sizes, the bike MFGs typically spec slack head angles specifically to prevent overlap (in reality, just about anyone on those tiny frames should be riding 650C wheels anyway, but it's another point of pride for some people to be on 700C for some reason). Anyhow, if you were able to find a Bridgestone catalogue from the late 80's, Grant Peterson was speccing drop bars on all the mountain bikes back then. Other than the different wheel size and sloping top tubes of modern bikes, gravel bikes are essentially the same beasts as Bridgestone MTB's of over 30 years ago. Those and all the John Tomac fanboys who put drop bars on their mountain bikes to emulate him...it was fairly common in that time period.

[martin manning]

Ah yes, good point about the front end geometry. I made a study of bike geometry and an Excel tool (see: http://www.os2.dhs.org/~john/Bicycle_Geometry/), and also of handling characteristics. Fascinating stuff! Junking up your thread here, but...