Electrical Engineering V3 - Developers

[QUOTE=LoneWolf_Recon;51309346]With the tools that you have bypassing the battery will be quite problematic. You'd need a much finer point soldering iron tip and smaller solder. However you might be able to jury rig some sort of fake battery using a tutorial like [URL="http://www.instructables.com/id/How-to-use-phone-without-battery/?ALLSTEPS"]this[/URL], that way all you need is a direct power supply right to the battery terminals.[/QUOTE] I saw that tutorial but the battery plug on the Nexus 5 differs so much from the battery edges in his example :(

You could attempt to dismantle the battery and re-use the connector that's already there (it'll likely be attached to protection circuitry). But that comes with its own dangers, and though that battery is swollen as it is and likely no longer too volatile (I once stabbed an old swollen phone battery with a heavy metal rod to try and show my co-workers what happens when they go up (outside of course), and nothing at all happened, not even smoke), I personally wouldn't risk it. Though considering the length of connector present on the old battery, it may be possible to simply cut the connector off of the old battery and solder directly onto it. Assuming you can adequately scrape that insulating layer off, that should just be copper underneath.

Yeah, what he said^ Don't open the battery. Just take off the cover, chop off the connector and solder the wires to the leads.

I decided to investigate the battery more and underneath the exterior I found a connector. [sp](it was kinda scary because once I cut through the outer layer of the battery a strange aroma started seeping out)[/sp] This is what I've done so far: [thumb]http://i.imgur.com/VVdDLJr.jpg[/thumb] [thumb]http://i.imgur.com/Ix6yl5D.jpg[/thumb] [thumb]http://i.imgur.com/tOYWmSL.jpg[/thumb] But when I tried it, it didn't turn on. I noticed the wires were frayed so I removed all the soldering I had done and made clear cuts on the wire insulation. I'm gonna try it again and see what happens. Question, can connecting the USB charger directly to the phone make it explode? Is there some sort of power reduction between the USB power going into the battery and the battery feeding the power to the phone?

[QUOTE=foszor;51313983]I decided to investigate the battery more and underneath the exterior I found a connector. [sp](it was kinda scary because once I cut through the outer layer of the battery a strange aroma started seeping out)[/sp] This is what I've done so far: [thumb]http://i.imgur.com/VVdDLJr.jpg[/thumb] [thumb]http://i.imgur.com/Ix6yl5D.jpg[/thumb] [thumb]http://i.imgur.com/tOYWmSL.jpg[/thumb] But when I tried it, it didn't turn on. I noticed the wires were frayed so I removed all the soldering I had done and made clear cuts on the wire insulation. I'm gonna try it again and see what happens. Question, can connecting the USB charger directly to the phone make it explode? Is there some sort of power reduction between the USB power going into the battery and the battery feeding the power to the phone?[/QUOTE] Uhm you are not supposed to apply 5V at that connector. It might work, it might not. Max voltage of a phone Li-Ion cell is normally 4.2V. I dont think you'll get it to work. Phones and other battery appliances stop working if they see something weird going on at the battery. You see that IC? That is the Fuel guage or BMS - you can be sure that the phone wont start if the BMS is telling something is up.

It shouldn't be too hard to design a circuit with an LM317 that provides the voltage you need for it to operate. I would also check for continuity across the component marked "P" as I think that's a fuse, make sure you didn't accidentally get it too hot because that could also likely be a point of failure. Failing that, as I previously suggested, simply remove the connector from the board entirely. The battery monitoring circuitry is no longer needed as you're not relying on a battery, but I would still try and find a 3-5 amp fuse to put in series as a precaution. You'll also likely have to spoof the temperature output with either your own PTC device (positive-temperature co-efficient, just a fancy term for "thermistor") or just wire in a resistor of a certain value. I would also suggest using a 4V supply to ensure you don't cause over-voltage issues.

The cheapskate method is to (ab)use the natural voltage drop of a regular rectifier to drop the voltage, so two ordinary silicium diodes in series will drop 5volt to around 3.6 volt. [editline]6th November 2016[/editline] But I know some devices need to be fooled about the NTC resistor normally in the battery, so measuring the value of the thermal resistor in the battery at room temperature and replacing it with a 'fixed' resistor with approx, value fools it.

But yeah, solder your supply directly to the solderjoint of the ribbon cable to prevent the BMS from controlling the output. And set your power supply to 3,5-4,1V.

Is this the shoulder joint you're speaking of? The 3 solder spots? [thumb]http://i.imgur.com/64jDnfW.jpg[/thumb] [editline]5th November 2016[/editline] Looking at the picture of the battery, top center text says 3.8v. [thumb]http://i.imgur.com/U2ve8nP.jpg[/thumb] Could I use something like this as the wall plug after soldering directly to the ribbon? [url]https://www.amazon.com/dp/B005REEWYY[/url]

The solder points on the circuit board, yes. You can de-solder the connector from that and then solder on your wires directly to the connector. As for a power supply, [url=https://www.amazon.com/DROK-Regulator-Converter-Switching-Stabilizers/dp/B00Q48BRFO/ref=sr_1_9?s=electronics&ie=UTF8&qid=1478408389&sr=1-9&keywords=adjustable+power+supply]this[/url] might be a safe bet.

[img]https://a.uguu.se/GqdjKTgpGItN.jpg[/img] [quote]I wasn't aware I could solder directly to steel plate until I found this baby.[/quote]

My foreman used non-electric irons to solder sheet metal together for weather-proof flashings and such. Not even gas-powered, you literally stick them in a miniature furnace, and they're little more than a copper head on an iron rod with a wooden handle. :v:

[t]http://i.imgur.com/ZgSD8kq.jpg[/t] [t]https://i.imgur.com/yGthuA0.jpg[/t] Almost done, it's going to look fantastic once I polish it to a nice shine. As for the base it will mount on I'm going to use 12mm chipboard with a wood veneer, probably black walnut.

So. My favorite thing to pick up off the side of the road lately has been treadmills. Usually I'll get some decent stuff from them, at minimum a high power PMDC motor, an AC to DC PWM driver, Reed/hall effect, 15A breaker, and some cables. At most, little fans, an incline linear actuator (AC bi-directional) motor, among other stuff. But they almost always got logic and control board's as a single main board. Which is useless unless I'm building a treadmill. But this treadmill is the simplest I've ever seen. It uses a pot to control the pwm driver and everything is pretty much isolated. Even the miles/speed indicator is separate, it's actually only battery powered and only reads a reed switch. This thing is so cute. [T]http://i.imgur.com/dZpcb5b.jpg[/t] Even threw the motor portion back together so I could spin it up. [T]http://i.imgur.com/WAmc96o.jpg[/t] [T]http://i.imgur.com/lXHgMpj.jpg[/t]

As an altium user, i'm really liking circuitmaker. Way better than eagle with no real restrictions and an auto router that doesn't suck (well, it's altium's autorouter). It's basically altium with no simulation tools and a more user friendly UI but they have changed the keyboard shortcuts for some fuckin reason...

[QUOTE=aydin690;51356826]As an altium user, i'm really liking circuitmaker. Way better than eagle with no real restrictions and an auto router that doesn't suck (well, it's altium's autorouter). It's basically altium with no simulation tools and a more user friendly UI but they have changed the keyboard shortcuts for some fuckin reason...[/QUOTE] Altium is p. fucking good but it still feels like a monster to work with (I'm still new to it) compared with Diptrace.

I switched from Altium to Multisim / Utilboard, works a lot better in my opinion and it has very good circuit simulation built in.

Are there any power resistors that are NOT coil wound? [editline]13th November 2016[/editline] Nevermind, apparently non-inductive power resistors are a thing. [editline]13th November 2016[/editline] But they are all large and expensive :why:. I guess i'm just gonna put a ton of metal oxide resistors in parallel like an idiot.

Just add a fancy cooling assembly and nobody will notice.

[QUOTE=aydin690;51367468]Are there any power resistors that are NOT coil wound? [editline]13th November 2016[/editline] Nevermind, apparently non-inductive power resistors are a thing. [editline]13th November 2016[/editline] But they are all large and expensive :why:. I guess i'm just gonna put a ton of metal oxide resistors in parallel like an idiot.[/QUOTE] You could always use a pencil (Provided you remove the wood around it).

[QUOTE=LoneWolf_Recon;51367576]You could always use a pencil (Provided you remove the wood around it).[/QUOTE] And if you hook it up to a high load, the wood will remove itself. Easy!

Do you guys know any good dealers for Nixie Tubes? I live in The Netherlands but I can't really find a shop where they sell.

[QUOTE=Staneh;51375159]Do you guys know any good dealers for Nixie Tubes? I live in The Netherlands but I can't really find a shop where they sell.[/QUOTE] ebay. IN-12A (ИН-12А) are pretty good value, you can get 6 for about €18.

Shitty thermal design 101. The holes int the PCB correspond to holes in a large aluminum heatsink. 6 TO-92 packages and 2 small NTC thermistors are meant to interface with the heatsink. The problem is there's no way of applying tension on them so they sit in loosely. The manufacturer, Behringer, just drowned each component in thermal compound and let the sit freely in the holes. [img]http://i.imgur.com/JUjzaWul.jpg?1[/img] Gooped parts. None failed but other larger devices attached to the heat sink did fail, which I want to blame on the thermistors not even touching the aluminum. [img]http://i.imgur.com/3FN7LsZl.jpg?1[/img] I ended up trimming some stiff rubber and jamming it into the holes alongside the parts so they at least have something pressing them tight against the heatsink.

:sick: I swear, half of the consumer electronics manufactures think that thermal compound is the magic white stuff that solves all their problems without actually designing proper thermal management.

[QUOTE=LoneWolf_Recon;51379998]:sick: I swear, half of the consumer electronics manufactures think that thermal compound is the magic white stuff that solves all their problems without actually designing proper thermal management.[/QUOTE] Bad thermal design really feels intentional sometimes like in later model plasma TVs. I've fixed several that have had fan mounts along the top but were never populated so your 5 year old TV throwing off 500W of heat from 30 or so IGBTs and diode arrays would fail way prematurely. I left the cover off one and the heatsinks on both sustain boards sat at 70 to 80C. Having a quiet 80mm fan on the hottest heatsink took it down to 40C. It's just stupid.

[QUOTE=No_Excuses;51380164]Bad thermal design really feels intentional sometimes like in later model plasma TVs. I've fixed several that have had fan mounts along the top but were never populated so your 5 year old TV throwing off 500W of heat from 30 or so IGBTs and diode arrays would fail way prematurely. I left the cover off one and the heatsinks on both sustain boards sat at 70 to 80C. Having a quiet 80mm fan on the hottest heatsink took it down to 40C. It's just stupid.[/QUOTE] Locations of the boards, as well. Friend of mine had to re-flow one of the boards in a monitor of his that was mounted in the upper section of the monitor. He was able to easily relocated it to a lower part of the board so that the heat from literally everything else wouldn't bother it anymore.

[QUOTE=No_Excuses;51378378]Shitty thermal design 101. The holes int the PCB correspond to holes in a large aluminum heatsink. 6 TO-92 packages and 2 small NTC thermistors are meant to interface with the heatsink. The problem is there's no way of applying tension on them so they sit in loosely. The manufacturer, Behringer, just drowned each component in thermal compound and let the sit freely in the holes. [img]http://i.imgur.com/JUjzaWul.jpg?1[/img] Gooped parts. None failed but other larger devices attached to the heat sink did fail, which I want to blame on the thermistors not even touching the aluminum. [img]http://i.imgur.com/3FN7LsZl.jpg?1[/img] I ended up trimming some stiff rubber and jamming it into the holes alongside the parts so they at least have something pressing them tight against the heatsink.[/QUOTE] honestly as soon as you said behringer I was completely unsurprised what is that for? is it something audio related? I have a behringer 4 channel mixer that's the noisiest flattest motherfucker I've ever heard. Behringer is pretty much as low of quality as you can get in the audio world. And while pro audio can get retarded, studio gear usually avoids that and Behringer is why you pay more for your studio gear [editline]17th November 2016[/editline] Like, Scarlettrite and Alesis are examples of how you can do cheap right. The Alesis 3630 and its mild defects defined french house, but the thing is a fucking brick and just can't be killed

[QUOTE=paindoc;51388564]honestly as soon as you said behringer I was completely unsurprised what is that for? is it something audio related? I have a behringer 4 channel mixer that's the noisiest flattest motherfucker I've ever heard. Behringer is pretty much as low of quality as you can get in the audio world. And while pro audio can get retarded, studio gear usually avoids that and Behringer is why you pay more for your studio gear [editline]17th November 2016[/editline] Like, Scarlettrite and Alesis are examples of how you can do cheap right. The Alesis 3630 and its mild defects defined french house, but the thing is a fucking brick and just can't be killed[/QUOTE] I've worked on a few Behringer products and I'm getting a bad taste in my mouth from them. They look pretty but internally it feels cheap. This here is an Behringer EPQ2000 2 channel amplifier.

Could somebody give me some advice/reading material on soldering? I really suck at it, and I actually need to get good with soldering, because I'm starting to deal with [i]really[/i] tiny pins at my job-slash-research place. Maybe I could get a PCB with pads of various standard sizes to practice on?