As a resistor, there isn’t a forward or backwards. Diodes and some capacitors perhaps, but resistors have no forward or reverse bias. Upside down might be a problem because all the electrons will fall out. /s
I dont think the resistors are faulty but the design. Resistors (especially low-ish value 22Ohm ones) are meant to dissipate energy as heat. Putting them in a cramped housing made of plastic, then using them to dissipate high power is going to build up heat in there. There could also be another component faulty that puts too much current into the resistors. They are probably part of the balancing circuit.
They are 22ohm resistors. You can see they are resistor by the marking R on the pcb. The first two digit is the value (22), the last is the multiplier (0), so it would be 22*10^0 =22 ohm
Maybe I’m looking at the wrong thing, but I don’t see melted plastic. I see a collapsed bubble (a “fisheye”) in the conformal coating that is providing moisture resistance to the components.
This trick might be more useful for people who are budget constrained. In the past I’ve resorted to cutting the plastic between the headers (making them unusable), so this is a nice alternative without the need for another tool. If budget wasn’t an issue I’d likely buy a much nicer iron and an extra wide knife-style tip.
Haha, I’ve done that too. However sometimes it rips the pads off or otherwise damages the vias. So instead I cut them along the other axis (parallel to the PCB), then remove the remaining nibs.
These days I mostly use a hot air rework station though. In my city this is integrated with many soldering stations on the market, for maybe an extra 10$. I think mine is Yihua brand, it’s quite OK.
I was ready to shit on this but I could definetely see some uses when there are a lot of through hole pins. I’d be a little worried about keeping the heat distribution even though.
I thought it might be useful to move the iron back and forth a little for long rows. Wouldn’t be perfectly even but would be better than concentrating heat in the center.
Hmmm… It does tick a lot of the boxes, but the ethernet protocol is way too complex with all of its layers and not reasonably implementable on a low-power microcontroller. Also it requires separate hubs for connecting multiple devices together unlike i2c, which is daisy chainable.
Indeed, I was looking for a simpler and lower level protocol. Thanks for mentioning the network protocol anyway, because I have never heard of CoAP until now. It may come in handy in the future (or maybe for someone else reading the post).
Thank you for your suggestions. Rs-485 seems to be what I was looking for. CAN could also work, but is it reasonably implementable? So far everyone who I spoke with about CAN said that it is a rather complex protocol with a lots of finicky details and an extra long standard. Perhaps I have just talked to the wrong people. I will look into it more thoroughly, and thanks again.
Thank you for your suggestion. Is it really that easy to implement? So far the people I talked with irl told me otherwise, but I will look into it and judge myself whether I am up to the task.
Exactly, hard/easy depends on your background. It’s been almost 20 years since I worked with it, I’m sure there are ready made libraries or chips implementing 99% of the protocol these days.
Something weird happened... So I edited my comment: Ive used those exact relays, 3 in a single prototype that I was tinkering with quite a lot, so what worked best for me in the end was mounting a DIN rail into my enclosure (Any box would probably work for you? I needed IP65 so I used a proper box with glands for incoming wires.) And then the relay boards were hot glued to DIN rail mounts... (The relay boards are then lined perpendicular to the DIN rail) That ensured that I could add or remove the rails as needed.
The rest of my circuit is also mounted on another DIN rail... Also allowing me to swap out main boards as I programmed/ upgraded them with minimal effort.
This was all connected by DIY 'ribbon cable' so that plugging and unplugging was also a breeze..
Granted this all might be overkill for you? Ive also have had projects that still live in shoeboxes and they work but obviously it all depends on your use cases?
Just remember, if you go the box route, to make your life easier, make sure the box is big enough to work in if anything is to be mounted permanently. Its a massive headache trying to feed one wire past all the others into the hole if you are working 20mm from the edge of your box.
Hope this helps!
(Second edit):
I read like my arse... If youre installing inside the switchboard and already have din rails, then a rail mount would be the most convienient solution
I ended up using spacers so that it does not come in contact with the metal box enclosure. Thanks for pointing out the mountijg holes. It was right there and I never noticed haha. I feel like an idiot.
askelectronics
Oldest
This magazine is from a federated server and may be incomplete. Browse more on the original instance.