You can get small project enclosures to put them in. Some PVC pipe and end caps could also work.
I would probably just use some good quality, adhesive heat shrink if they are out of the way though.
Adding on to this line of thinking, maybe a thin plastic tube and epoxy to encase it with the solder joints. (Bonus points for using thermal epoxy, since it is a resistor after all.)
I have seen Bigclive on YouTube encase resistors and a diode rectifier in standard epoxy for use in lighting, so heat probably won’t be an issue now that I think of it.
don’t really accomplish anything. The first line is bit shifting to the right 8, and then you just bitwise and it resulting in the same thing. For example, starting with input_bin:
So, every time you go through a cycle of the for loop, you’ll just start with the same values in upper_byte, and lower_byte. To sequentially output each shifted value, you’ll instead want something like:
Note: Lemmy has a bug where it doesn’t format some symbols correctly, so the left angle bracket gets formatted as <. The same issue exists for the right angle bracket, the ampersand, and I would presume others.
The “typical application circuits” on page 2 in the datasheet ww1.microchip.com/…/MCP1700-Data-Sheet-20001826F.… shows both input and output being decoupled with a 1µF cap, have you tried that? I haven’t worked with the MCP1700, but I have had other LDOs fry themselves because the decoupling malfunctioned.
I’m not saying that your LDOs are fried. What I am saying is that some LDOs don’t take too kindly on not having the company of some nice caps.
What just caught my eye is that the datasheet specifies ceramic non-polar caps. That seems a bit weird. Just drawing a non-polar would have made sense, but specifying that it is a ceramic is strange. Using a ceramic makes sense, I mean there are 5 times the ceramic 1uF caps on digikey than there are electrolytics, but it should be technologically agnostic… I’d probably try to get some 1uF ceramics for testing.
Well I guess, I’ve got a sweeping function gen and a 4ch DSO… I’m gonna look into that and get back.
Caveat: my engineering diploma in embedded electronics is 10 years old, and it’s been awhile since I’ve done more than just the odd solder job. So it’s going to take a little while.
@gondezee when you say “plot a frequency sweep” what you’re looking for is just the usual voltage/time graph from a scope? No resistance in parallel to the capacitor for discharge? No fixed resistance in series? No x/y graphing funny business?
Or are you looking for a bode plot? I was hesitant in my first response because I thought I remembered Dave doing a bode plot with a sweeping gen and a scope, but I wasn’t sure if I could find it. I could m.youtube.com/watch?v=uMH2hGvqhlE
I think I’ve managed to do what you asked, let me know if I messed it up.
I got my function gen to do 6.1-12 in two decades x100 and x1000. The sweeps are almost linear after the first 500ms, meaning that each horizontal division of each 200ms denotes the following:
I’d agree with the tip of that ground plane is close to the high voltage part. And there’s still space left on the right.
The ULN2003A claims to have the flyback diodes and they’re connected. So you don’t need another set.
I’m not an electronic expert myself. But I don’t get why the fuses are the way they are. Most of the times I see boards having one fuse and when it’s blown, the whole board is separated from electricity. You’re kind of splitting it up 3 ways.
And the 5A of the fuses doesn’t match with the 10A rating of the relais or the 400W you wrote for the connectors. But I get that you have maybe 6 motors moving simultaneously.
(And why do you have the N trace to the connectors split in the middle and a whole other trace going all the way around? Is that to balance things when there’s much current going over that single trace? Or to match the 2 fuse design?)
The main reason for splitting up the relays into two sets is that with 10A traces the connector pins would violate minimum separation distances. I would have to get even larger connectors. The ones in the design have 5 mm pitch.
I’m assuming the original board also did this for the same reason although their board is set up for 8 motors split into sets of 4.
I’ve also had some trouble sourcing a 10A fuse suited for inductive loads but I’m sure I could find one with some more time.
The whole board is on its own house circuit fused with a 16A breaker.
Thanks for explaining. Yeah, I’m sure it’s pretty much alright with your circuit breaker. I suppose your main concern for having the fuses is so that those relais can’t start a fire once the current is between 10A and 16A for too long. I was just thinking about failure modes. And having something fail, the fuse blow and then half the board still has 230V feels a bit strange. But I guess it’s alright. I’m not an expert anyways.
I saw those PCB mounted 5V power supplies coming up in ESP32-projects before. I always thought they were some cheap chinese stuff and you shouldn’t trust them. But if they have a proper fuse inside and do proper 5V… Maybe I need to change my mind and start digging deeper.
Idk about mixing 10A relais and 5A traces and connectors. Everytime I buy some shelly stuff, I just have a look at the print on the relais before I wire something up. That’d be wrong in case someone had made the traces smaller. But I guess you can just write 5A MAX on the pcb and everyone can see that, even if one day somebody else does some maintenance. In this case you obviously need a 5A fuse.
increase the resistors by a factor of 100 or so and add a very small cap across the lower one. The cap inside the ADC is absolutely tiny, pF at best. So a 100nF cap would easily do the trick and supply the voltage as required.
I believe this lead configuration was designed to help with vibration resistance at very low cost, negating the need for a glue down. It could also be a bit more compatible with conformal coating? I suspect they’re special order on account of the leads and maybe the dimensions (could be demanding at the time), and the space constraints didn’t really allow them to claim a full 680μF.
I’ve never tried super hard, but I’ve never manged to source these from anywhere. I think this technique has mostly been replaced by multi-lead (three to five) configurations. I don’t think I’ve seen these from anything built in the last 20 years or so. I suspect you’ll have to retrofit to get things running again.
There’s some risk but I’ve managed to make a standard snap-in capacitor work by using a pair of pliers to rotate one of the leads on it’s rivet and bending both leads for the proper angle. This doesn’t help with vibration so I’d recommend fixing it with selastic as well.
Alternately you can modify the board to fit standard capacitor leads if everything lines up ok. Don’t forget that the PTH in the mounting holes might be connecting planes on opposite sides of the board. Make some sturdy vias if necessary.
If you’re really feeling froggy you can take a page from the vintage electronic restoration handbook and (kind of) restuff the cap. It’s usually done to be pretty, but in this case you could do it without care for looks and only in order to retain the terminals. This may be unwieldy given the size. I imagine it’d essentially be cutting the base off, wiring it to the new cap, and gooping everything together neatly with silicone.
I concur on the retrofit. It’s a two layer board, and the negative and positive rails are on opposite sides. I should be able to reuse the slot for the negative rail and make a slot for the positive (bottom side) rail. That way I can still get snapin terminals, as I’m concerned about the cross section of terminals if I had to resort to some round ø1.0mm pins.
I considered the approach you suggest with turning the terminals on the rivet, but all the riveted terminals I’ve seen have been potted partly, so I’d be concerned that turning them would put stress on the rivet and internal connection. That hasn’t been an issue for you? Anyway the caps I’ve found are just short of 20€ a piece, and I’m cheap, so I don’t feel like playing around.
Restuff the caps? Has anybody ever called you a cowboy? 🤠 I guess you could do that from an aesthetic POV, and maybe with enough selastic it would work. But somewhere in the back of my mind I know that it will fail at the worst time, and I’ll have to retrofit some other caps anyway… Only this time it’ll be raining and 2°C when I have to take the inverter apart.
Thanks for the idea of retrofitting. I was so stuck sourcing a drop in replacement that I hadn’t really considered that approach. The real estate is there to take a drill press with a 1mm drill and make a slot for normal snapin connectors. It’ll even maintain the same center, somewhat at least. Time to play with some selastic!
I’d be concerned that turning them would put stress on the rivet and internal connection. That hasn’t been an issue for you?
Hasn’t come up yet in a handful of tries over the years. The clamping force in the ones I was working with was insufficient to turn the rivet when the lead was rotated so I don’t suspect damage. The potted/sealed caps wouldn’t tolerate this at all, nor would any given particularly well riveted model. I totally understand not wanting to get weird with expensive parts. The one’s I was working with were only a few USD. https://discuss.tchncs.de/pictrs/image/0037be12-4142-480e-b8ea-db83ea241f1f.jpeg
I figured I’d dig through the junk pile and see if I could demonstrate. On the left is an Elna CE-W series 470μF 200WV, Ø30mmx50mm I had lying around, probably from the late 80s/early 90s. These are likely from an old switching supply, back when they made them specifically for US 120V mains. Just included it for fun as I wasn’t sure I still had one around.
The one on the right is an unbranded 1200μF 200WV Ø30mmDx35mm with a 2011 datecode. I used the pliers in the background to give one of the leads a 90deg turn. It’s dodgy with such thin leads as these, but it can be done. Solder tie lugs are much better as they have a flat square lead shape that’s less likely to tear off. So definitely possible, but definitely dodgy.
Restuff the caps? Has anybody ever called you a cowboy?
I don’t always have the best ideas, but I do tend to have a lot of them. :)
I try to cast a wide net cause it’s not always obvious what priorities folks have in their repairs. I doubt anyone would care about the aesthetics, for sure, but you would get to do all your arts and crafts work without involving the board itself, which could make some folks nervous.
Time to play with some selastic!
If you have time for the shipping you can get some Kafuter K-704N from aliexpress et. al. pretty cheap. It’s exactly the white selastic used for electronic holddown. Also the datasheet for whichever capacitor you order should have details for the recommended board footprint and drill size so you can be sure things will line up.
Thanks for all your input, it’s been fantastic. And the ideas thing? Right there with you pal.
For future reference, I found a source for the cap. Turns out that setting your parametric filter to exactly 660uF was the trick. Found chemo-con EKHJ451VSN661MA59M on mouser with a moq of “only” 200@12€… But digikey sells them individually at the same price.
I hope you know the consequences of having batteries in parallel? I mean, if they have different voltages you’ll get some current going between the batteries until they equalize. And the consequence of having one in reverse is probably also much worse than having them in series.
I don’t know. You’re connecting the two batteries. The one that has more voltage will charge the battery with less voltage. And because it’s just a strip of copper between the two, without significant resistance, it’ll happen fast. The thing limiting current flow is probably the internal resistance of the battery itself. And for example alkaline batteries, you’re not supposed to charge them.
I haven’t tried what exactly happens. AA batteries aren’t as powerful as for example Li-Ion batteries. So you’ll probably be alright. Maybe in the worst case one battery gets hot and smells funny. But I don’t think this will cause a proper fire. If it’s only a bit, it’ll get a bit warm and you waste some energy, that’s probably it.
If you connect one in reverse I’m not so sure anymore. I once had a rechargeable battery that was connected in reverse get really really hot and bulge. Once you do things like this with Li-Ion rechargeable batteries, I think you’re in the realm of starting a fire.
a display driver that connects to that flat ribbon cable to the display.
a MCU or computer to host your programming and send commands to the display driver
power, wether it’s battery, USB, or induction…
You can separate the screen from the driver and have the e paper show the last image. The one thing I’d be worried about is how fragile the components are on the side of the rapper display itself as well as the ribbon cable.
Also, you mention 150+ cards. Think of the time it would take to change each one separately with a dock. Connecting the display to the driver is not hot pluggable you would likely need to power cycle the whole thing at every card. Plus the damage risk of constantly connecting the fragile connectors.
Thanks, I was aware of some of those obstacles. But this adds a little more detail, to the point where I don’t think it would be economical to repurpose this for this. It sounds like my idea may be possible with current off the shelf tags, but I think the dock would end up being way larger than I was initially imagining. It also seems like I am looking at like a minimum of $500 in parts for a prototype, even if I were somehow able to get the tags for $2 a piece.
You misunderstand the dock interface. The plan would be to insert the ribbon into something more durablee to bridge into the dock to be more like a cartridge. The dock will be expensive as I would plan for either all or most of the “cards” to be docked at once. It wouldn’t be a insert, wait, insert wait, instead it would be insert all the cards into their slots after play.
I also realized that the dock will need to be a little more complex then I originally thought as well. A lot of games have extensive burn and draw mechanisms leading to an extensive set of cards. What you could do is only have the amount of cards you would need in the base set for most of these games that are actually in play at any given time. The rest of the “cards” could be held in the “docks” memory, then “printed” when you draw a new card. It would add a little bit of time to the games, but you could dramatically cut the amount of physical “cards” or tags you need for many games.
You could potentially modify a game to work with those cards. Making cards able to change state or add extra states (that would usually be extra cards) to a single screen. I like your idea. Maybe the idea would not be a retro fitting but a ground up new mechanics for the mage?
I found a few references to this exact model on candlepowerforums.com which I believe has more folks who own(ed) incandescent lights. Not that has been such a long time, but LED technology advanced very quickly. Not sure if that will help your search.
Arduino and esp32 are both good places to start. On YouTube look up ralph s bacon I think he is - He does lots of microcontroller stuff, and of course the likes of big clive will teach you all about basic electronic circuits.
If you’re a complete newbie, get a kit and work through the tutorials.
Stuff you’ll need at first is a microcontroller, prototyping breadboard and a few components (should all come in the kit of you go that route). When you have something that works that you want to keep, you can think about a cheap (ish) soldering station and either veroboard, or look into getting your own boards made.
A multimeter will help a lot (cheapish will do) and depending on how deep you get, a bench power supply and an oscilloscope, but you can live without those for a while.
Get good quality solder, and using extra food quality flux changed the game for me. If you are an older person, magnification really helps too!
Get components in 10’s or more as you’ll save a little and it doesn’t matter much if you let out the magic smoke. For hobby stuff, Alix is your friend.
You want to get into microcontroller programming somehow. The Raspberry Pi Pico may be a good target to start with. The documentation is well made and you have the choice to either use C++ or Python for programming.
askelectronics
Top
This magazine is from a federated server and may be incomplete. Browse more on the original instance.