I noticed that when I use the wireless charging of my Nokia 920, that my watch (Oceanus -- Casio actually) does not sync with the USA Atomic clock ...
I have to move the watch from the night stand where the wireless charger is to another location about 8 feet away to get it to sync. Has anyone else noticed this? I have not played with the distance needed, but it did not seem to make a difference if it was within 3 inches or 8 inches away ... but 8' works ...
I thought that the charger "shuts off" when the charging is done and then the watch should have synced later on in the night -- it tries several times a night, and the last on (at 4AM) should have been after the phone was charged and the wireless system stopped -- but I guess that it could be restarting to keep the phone charged through the night ...
Anyway, does anybody have any thoughts (or also experienced it) on the Qi charging and interference with the Atomic watch finding the time?
I vote that you write a strongly worded letter to the Atomic clock facility in Boulder, CO and tell them to fix their damn system.
Didn't try it out but the charger does not turn off - only the phone stops charging. It is still running on the power supplied from the charger instead of starting to run of the internal battery (which would start running down the battery again so the charger would have to recharge the battery which would add charging cycles that are still somewhat detremental to battery performance). It should work if you remove the phone from the charging plate though.
As to why it jams the signal from the atomic clock I can't tell you that for sure but as I always had problems to get any clocks to sync properly inside several flats it seems those signals quite often are rather weak and therefore are jammed rather easily. I guess there is no cause for concern from that.
Havnt tried this stuff lately.
http://winappleworld.com/how-wireless-charging-works/
You can check this out.
Known Interference issues
Speaking to several engineers on the topic, there are known automotive system interference issues.
Personally I can verify that my two Nokia Qi DT-900 chargers cause severe interference with outbound on-phone (non bluetooth) audio on both a Nokia Lumia 920 and an iPhone 4, just being near a non-charging but connected pad. The range of interference is several feet. Of course the iPhone is a non Qi device.
I assume muddtt is being sarcastic in the comment above.
Anyone have issues on a different pad?
A wireless charger emits a powerful magnetic field. Keep anything sensitive well out of the way.
Wireless Charging interference
RJH57108 said:
I noticed that when I use the wireless charging of my Nokia 920, that my watch (Oceanus -- Casio actually) does not sync with the USA Atomic clock ...
I have to move the watch from the night stand where the wireless charger is to another location about 8 feet away to get it to sync. Has anyone else noticed this? I have not played with the distance needed, but it did not seem to make a difference if it was within 3 inches or 8 inches away ... but 8' works ...
I thought that the charger "shuts off" when the charging is done and then the watch should have synced later on in the night -- it tries several times a night, and the last on (at 4AM) should have been after the phone was charged and the wireless system stopped -- but I guess that it could be restarting to keep the phone charged through the night ...
Anyway, does anybody have any thoughts (or also experienced it) on the Qi charging and interference with the Atomic watch finding the time?
Click to expand...
Click to collapse
My Oceanus OCW-T400 sync flawlessly on my wrist during the night where my Nokia Qi charging pad is beside the night stand next to my bed.
Depends on the location where you place the watch to sync, sometime the propagation of radio signal vary during the day and the best should be at night. Try sync it manually in different location inside your home to find the best location.
The following is some testing I did out of curiosity. My methodology is decidedly short of scientific, don't take any of it as the gospel truth/hard fact. Proving me wrong is encouraged.
It's also well into reasonably-TL;DR territory. There's a summary at the bottom.
A while back, I bought a Xiaomi power bank, and with it a reasonably powerful charger to fuel it.
During one particularly sleepness night, I'd settled down in bed with my phone - which was nearly dead after laying neglected on my desk for a couple of days - and set it charging whilst reading news and whatnot. A half hour later, I noticed that it had accumulated a surprising amount of charge, despite me using it.
Curiosity piqued, I bought a Charger Doctor sort of thing - which from here on out I'll refer to as a "monitor". It's one of these specifically (chosen based on review found here), to see how much amperage the phone actually pulls if given as much juice as it wants.
Unfortunately, these tests are a bit flawed - I have a pair of 24/28AWG micro-USB cables on order, but for the moment all I have is the input pigtail that's on the monitor (it also has a micro-USB port for input) and a short cable that came with my power bank to go between monitor and phone. I think that the input pigtail is limiting the maximum delivered amperage, because the amperage doesn't rise above the maximum observed even while in use on the charger (more on this later). I'll get another batch of samples when the new cables arrive.
Does not seem to be the case, or at least, the pigtail is reasonably capable. Switching to the micro-USB port actually lowered the current delivered.
It looks like short of soldering a new pigtail in (using thicker wires), there's nothing I can really do to eliminate this potential bottleneck. The pigtail is short enough anyway that it might not be adding enough resistance to make an appreciable difference.
The charger used was a Xiaomi MDY-30-EC (2A output max, Quick Charge 2.0-able apparently). In hindsight, I should have gotten an MDY-30-EH for future-proofing (2.5A/QC 3.0), but you know what they say about hindsight.
I drained the phone to 10% and set it charging, checking on it every now and then to see what it was doing. Then I proceeded to forget about it for a bit, so it kind of got away from me, but the power curve for 10%-33% proved to be fairly flat.
10% ~ 33% - ~1.58a
33% - 1.5a update: observed to still be holding 1.58a up to at least 43% in the second run
50% - 1.14a
57% - 1.05a
60% - 0.965a
79% - 0.865a
80% - 0.775a
83% - 0.645a
85% - 0.565a (0.50a)
87% - 0.505a (0.465a)
87% - 0.475a
95% - 0.165a (~0.115a)
100% - ~0.07a (intermittent)
Note that for much of the time above 60%, I had the screen on at the lock screen and auto-dimmed ("keep awake while charging" on via Development Options). It wasn't until 85% or so that I thought to check if the phone will pull additional needed power directly, instead of draining the battery. It does seem to, so at 85% and 87% I shut the screen off and recorded the draw.
As you can see, the phone will use up to 1.58 amps if given as much, and stays above 1A until 60% (where it suddenly drops to 0.96A). It's only when it reaches about 80% that the stock "fast"/travel charger becomes adequate, and 85% when a standard charger or USB connection can charge it with the screen off, and neither of those leave much if any excess capacity for the phone to consume if it's awake/being used.
Overall, it seems like quite a sane charging curve, edging into overly cautious. I'd guess this is because the battery is technically non-removable, and they didn't want people sending their phones in under warranty for the battery replacements that a more aggressive charging curve might have caused. Not that any of it mattered, what with them only ever offering a 750mA charger anyway.
Again, this test is flawed from the outset due to lack of a decent input cable. I seriously doubt it pulls much more for charging, but a proper cable might allow the phone to pull more for active use; at 10%, the current didn't go above 1.58A even while messing with it.
Fast-charging the battery might also cause longevity issues, because of potential heat build-up. Don't be an idiot like me and set it next to your pillow, only to find it under said pillow or blankets in the morning all toasty and only half charged because the safeties - yes, surprisingly we do have over-temperature safeties - kicked the charging circuit off. Also probably not the best idea to do gaming or anything else intensive on it while charging at full tilt, what with the processor's EMI shield being in direct contact with the battery and all.
Further on this: The heat build-up doesn't seem to be bad, with the phone sitting back-down on a wooden desk. In fact, the casing on the charger itself got much warmer than the back cover of the phone after half an hour of running at maximum input, to the point I started worrying about it instead.
I would tentatively say that "fast-charging" won't hurt the battery, at least, not by way of overheating it.
Some further power draw tests. Anything under .5a might be (probably is) inaccurate to some degree, and the monitor's minimum seems to be 0.07a.
Booting the phone - 0.44a (note that this isn't even enough to power the boot process what with the CPU saturation, so rebooting at <10% is probably a bad idea)
100%, screen on at launcher, brightness maximum - ~0.195a
100%, screen on at launcher, brightness minimum - below cutoff
Following is at 100%, brightness maximum:
GPS on (no satellites in view) - 0.30a
Bluetooth on (active scan) - ~0.42a
Bluetooth on (passive, unlinked) - 0.215a
Bluetooth on (actively broadcasting) - intermittent bumps to ~0.24a
CPU loaded (1.3ghz) (Passmark integer math) - ~0.78a
GPU loaded (Passmark 3d test - complex) - ~0.59a
GPU loaded (3dMark Ice Storm) - ~0.42a
3dMark physics test - ~0.68a
In summary:
We can use up to 2A chargers (possibly more if excess capacity is needed by the phone being under load while charging), despite only ever having been officially offered a 750mA charger at most. Thanks for that, Motorola.
The charging circuit supports bypassing the battery for direct power, if charger capacity beyond what's needed for topping the battery up is available
The screen uses a fairly tiny amount of power at minimum brightness
The screen uses a lot of power at max brightness
The GPS also uses a lot of power, roughly half that of the screen at full brightness if measurements are accurate
The GPU uses a large amount of power (note: real-world usage for the GPU outside of games is normally very bursty, but tends to get saturated a lot for UI acceleration in LP/MM)
The CPU uses a ton of power (note: real-world usage generally has the CPU napping at 300mhz where it barely consumes anything, and/or bouncing between 600mhz-1ghz)
More:
The charging circuitry seems to be able to utilize capacity above 1.585a, based on momentary spikes to 1.6a/1.64a. I'd guess my charger is a limiting factor here.
Our phone meets and exceeds Quick Charge 1.0's nebulous "30% in 30 minutes" marketing blurb/guideline.
New USB cables arrived today. Some additional things:
- Monoprice USB cables kind of suck. One can only pull slightly less than the short ribbon cable that came with my power bank, the other one pulls a good .15a less. I'll have to fiddle with them a bit to see if it's a connector pressure issue or what. Not really what I was hoping for from 24AWG cables.
- Charging starting at 5%, the phone tops out at about 1.585a, with occasional spikes (probably combined hits to CPU+GPU+disk) to 1.6-1.64a.
- The 1.585a number is only for screen on and working, actual charging seems to be capped at roundabouts 1.5a.
- The charger monitor actually has higher resistance through its micro-USB port than it does the crappy little pigtail...hooray for Made in China I guess. Maybe I'll make a new pigtail of this thick old cable end I have laying here...
- At maximum speed and the screen dimmed, with the phone sitting at ~26%, the lock screen reports 1 hour, 22 minutes until full. Not too shabby at all, if it's accurate.
For my next trick, I'll measure the time it takes to go from ~5% to 60%, since emergency charging is probably more relevant to people, and I'm a bit curious about how it compares to Qualcomm's super-special Quick Charge.
Last post, since I feel like I've gotten about as much as I can out of experimenting with my current equipment. I'll edit the first post to reflect all the information so far.
In 33 minutes, the phone recharged 38% of its capacity (coming to 43% total). This is actually into Quick Charge 1.0 territory (which seems to aim for 30% in 30 minutes using "up to" 2A), so that's pretty neat.
At this stage, unlike the earlier test, it was still pulling a steady 1.58a...with the screen off. *shrugs* I'm not sure what to make of it, maybe there's something I'm missing. It was markedly warmer in here this time, so if anything the charging circuit should have began ramping the current down sooner.
And yes, 1.58a again. I'm not sure what's going on, it just randomly decides it doesn't want to charge at full speed.
I'm wondering at this point if it's not my charger that's a limiting factor. It got fairly toasty earlier when the phone was charging balls-to-the-wall, and it's only a (supposedly) 2A adapter. I do need to buy another charger, as a household member needs a new one, maybe I'll look into getting a 3A unit...
Anyway,
In 60 minutes, it had recovered 66% (coming to 71%). I was going to go for timing 60% (which appears to be the Quick Charge 2.0 target), but instead set an actual hour timer because 1: we'd missed it anyway (60% in 30 minutes) and 2: I didn't want to wake the phone up every now and then to see what % it was at, nor did I want to leave the screen on and affect the result.
'course, the QC 1.0/2.0 targets don't mean much, because they don't specify the capacity of which you're trying to fill 30%/60%. Still, now you can brag to your friends that yea, you totally have a Quick Charge-capable phone...and it's almost true.
people do this, right? compare phone-charging e-peens? no? : \
So yea, hey. Small battery even in its day, but if you plug a big enough charger (or a capable power bank) into it, it juices up pretty fast.
This post didn't seem to get enough attention.
Very thorough and enlightening.
I think I have a 2amp charger laying around somewhere and I can plug in a fast-charge USB cable from my brother's Samsung G6 Edge.
I'll see if it speeds up charging at all.
How to avoid "reboot" on "ignition" and "sleep" on turning off the car
I have a 6,95inch autopumpkin carkit with Malyask Firmware and it actually runs just perfect.
Except for 2 things that are really annoying:
when the autoradio is already switched on but the car engine not running and I switch the start key to start the engine I get a short:"shutting down/reboot" on my carkit device and it takes a while for it's back online with all the background programs running. It shouldn't reboot/shutdown.
Maybe some wire I connected wrong? How can I avoid this? that's my first issue.
The 2nd is even more important. I use the device to keep a log on my tracks using mycartracks. And it works just fine. However, each time I get at the place of destination I have to leave the unit switched on for a while (30seconds no movement) for the mycartracks to understand my current track has to be stopped and next time a new track has to be recorded.
Sometimes I'm in a hurry, I forget to wait. If that happens in the evening when returning home, next day when I start the car the unit thinks I'm still driving my track of the previous day so instead of recording a new track, its continuing the track of the previous day. So the log and statistics aren't accurate and I manually have to fix the tracks with a manually edited GPX data file which is A LOT of work!
To avoid this, when I switch off the unit, it should simply keep running in the background for a few minutes. Black screen but not shutting down altogether.
Now from what I can see, the unit however doesn't go completely offline! Because I can set it to 30 minutes or 1 hour or 2 hours in "sleep" when turning off the car and that actually does work. Because when I start the car within that time, it doesn't start from scratch but simply lights up the display and everything is already booted. So there is power in the background keeping the unit in this "sleep" modus. So there must be some internal power supply or still using the car battery for this modus? But how can I use that, to avoid the unit to go into sleep immediately after the car is turned off?
So what I want:
when I shut off the car, the unit keep running at least a few more minutes before auto sleep/shutdown
when I start the car, don't reboot/shutdown but simply keep running.
Any ideas here how to accomplish that?
Thank you all for your advise on forehand.
I know I can add an additional battery in the car behind the unit to give the unit some more power for 10 or 20 minutes and I also can design the electrical wiring to make sure the power is going to the unit and not backwards to the car battery. That's not the issue. The issue is, I think the unit has already a permanent power supply from the car battery and I simply want to wire it, that it doesn't go to sleep/shutdown instantly and doesn't reboot/shutdown upon starting the car. That must be possible without installing additional power supply.
So I hope someone has an idea how to wire it properly without me testing how to do that.
I'm curious about how much power it is using while it is in sleep, because if it is not that much I would prefer to hardly ever let it cold boot.
Ultima_Thule01 said:
I'm curious about how much power it is using while it is in sleep, because if it is not that much I would prefer to hardly ever let it cold boot.
Click to expand...
Click to collapse
You mean as in: " connect the red wire to the permanent +12V line?"
I could put an Ampere-meter between tomorrow and have a reading. Since I replaced the battery in the car, original 48Ah at 12V, with a 64Ah at 12V,
that gives me addition 16Ah.
Or, if in sleep it uses 0,5Ampere I can keep it running for 32 hours without getting below the original battery energy supply.
Or if in sleep it uses 0,2Ampere I can keep it running 80 hours without touching the original 48Ah.
But I'm sure it'll be lower than 0,1 ampere because even with the 1 hour delayed shutdown after ACC switched off, after just 10 minutes the unit is pretty cold again.
So I'm sure it draws very few Ampere in sleep modus.
But point is, in sleep all background programs don't run anymore and thus the track recording isn't working either and thus doesn't recognize that the track recording should
be stopped as the car isn't moving anymore.
duiveldoder said:
when the autoradio is already switched on but the car engine not running and I switch the start key to start the engine I get a short:"shutting down/reboot" on my carkit device and it takes a while for it's back online with all the background programs running. It shouldn't reboot/shutdown.
Click to expand...
Click to collapse
Not sure it's a wiring issue; mine does that too. Pretty sure it's because the car is designed to cut power to things when the ignition is first turning so all the battery's power can go to the starter and not get wasted on things like headlights.
Or, we both have it wired incorrectly; I'm certainly no expert.
---------- Post added at 03:43 PM ---------- Previous post was at 03:39 PM ----------
As for MyCarTracks;
I assume it's a similar issue. My dashcam constantly records 1-minute videos and pieces them together. When I take the unit out (and it loses power) the most recent file is lost because the unit was powered off before it was saved.
Perhaps both issues can be remedied by running a fused line directly to the battery (thus bypassing the the part that cuts all power when the car turns off). I'm assuming you've already adjusted the setting to try to get the head unit to sleep for two hours upon being turned off instead of instantly turning off.
NYCAR said:
Not sure it's a wiring issue; mine does that too. Pretty sure it's because the car is designed to cut power to things when the ignition is first turning so all the battery's power can go to the starter and not get wasted on things like headlights.
Or, we both have it wired incorrectly; I'm certainly no expert..
Click to expand...
Click to collapse
As engineer I can assure you everything is wired correctly and you're right the design of a car is that most of the power goes to start the engine. But it's not like you make it sound like there's a switch that cuts off power to other parts of the car.
The theory behind it is very simple: The inner resistor of the car engine is simply much lower than the other devices. So all the current goes through there and not enough current through headlights and car stereo.
it's like this: you have a flow of 100 liters of water per second. 1 watermill needs 20 l/s and another 20l/s and few others each 10l/s now you split the water stream in 2 parts. 1 part is 10cm deep and 10cm wide and the other part is 10cm deep and 90cm wide (that's the car engine)
of course for all the other users there isn't enough water anymore.. used to be initially, but now not anymore. So I don't really cut them off, it's just most of the water goes through the 90x10 canal.
If I close that canal of 90x10, I still have my 10x10 left, but now there's again 100l/s so it just flows faster (higher voltage) (which is 12Volt as the battery doesn't get higher) which means logically while you still have 12volts on your car engine starter, the voltage of the rest drops
along with the current(ampere)
so you don't have anything in your car that switches off or cuts the current/voltage of headlights, radio, etc. It's just you're opening with the car engine a wide canal that allows massive ampere and all the 12volt on it, so not much left for the other users.
To avoid this, I could install a 2nd 12 volt battery behind the car radio, with a 1-way diode and a small 50Watt 0,3Ohm to prevent a shortcut parallel with the car battery so it's loaded together with the car battery but when starting the car engine there's no voltage drop behind it to the car radio
nor is there any current flowing backwards. that would work. But obviously INSIDE the radio there's a condensator or internal battery strong enough to keep the unit in sleep mode for at least 1 hour and that should be sufficient to instead of sleeping 1 hour keep it running for a few minutes.
That's a firmware question. Since there are firmware guys here online, malyask i.e. one of them might be able to reprogram the firmware so I don't need to install additional equipment.
NYCAR said:
As for MyCarTracks;
I assume it's a similar issue. My dashcam constantly records 1-minute videos and pieces them together. When I take the unit out (and it loses power) the most recent file is lost because the unit was powered off before it was saved.
Perhaps both issues can be remedied by running a fused line directly to the battery (thus bypassing the the part that cuts all power when the car turns off). I'm assuming you've already adjusted the setting to try to get the head unit to sleep for two hours upon being turned off instead of instantly turning off.
Click to expand...
Click to collapse
yes tried that. but "sleeping" before shutdown is really shutting down all background software including Wireless so that's no help. Also when having an additional power unit that could maintain the unit to keep running for at least 1 hour, taking out the car keys would still
put the unit into sleep
It's really the firmware that needs to be changed a bit.
What about a 330uF capacitor on the ACC+, behind a diode? I did that the first day after I've installed my HU, never regretted.
sorinakis said:
What about a 330uF capacitor on the ACC+, behind a diode? I did that the first day after I've installed my HU, never regretted.
Click to expand...
Click to collapse
330microfarad? That's enough? Wow! Never expected that few energy would be sufficient.
Can you state the precise brand, model, of the capacitor? of if you can't remeber anymore, what type: i.e. 14 Volts, 330uF, and Elektrolyt, Frolyt, etc?
btw, if I switch off the car and thus 0V on the acc+, how long the unit still has before shutting off?
I mean, I really need it to keep going for at least 1 minute that's the absolute minimum. 330uF won't be enough I'm sure. But if you can overcome 3 or 4 seconds already,
it means, I'd need a 20 times larger capacity of course. thus 6000-7000uF
With a 330uF/25v behind a 1N4001 (both recovered from some old project), I get about 8 seconds of holding the HU on. My problem was that, after turning off the car but leaving the radio on (on ACC), when I wanted to turn the engine on, the HU was shutting-down then coming back.
I think that, for keeping the HU on ~30 seconds, I would go with a 2200uF/25v (be prepared with a 4700uF in case you don't get enough time with the 2200). The HU gets it's main power from BAT+, the ACC+ just goes to a GPIO pin and sends a "soft power" signal, hence you don't get a huge power consumption on that rail.
If you are going that route, why not a timer delay with a 555? Please keep in mind that I am just throwing terms around. I did some 555 projects in the past, but nothing that required enough power to run a head unit.
This might be something.
https://www.amazon.com/GERI-Delay-R...rd_wg=sN6Ca&psc=1&refRID=7HA9ZFGPQZ8VSQT19K05
in the same line: why not using a PIC and programming the time interval to the second? or why not using an Arduino timer? or a TCO RTC such as DS3231? although valid questions, I see no need for such complication when, as I said before, the power consumption on the ACC+ rail is negligible, so a simple R/C (without external R) would do the job. Of course, any other implementation of any kind of timer will work.
NYCAR said:
If you are going that route, why not a timer delay with a 555? Please keep in mind that I am just throwing terms around. I did some 555 projects in the past, but nothing that required enough power to run a head unit.
This might be something.
https://www.amazon.com/GERI-Delay-R...rd_wg=sN6Ca&psc=1&refRID=7HA9ZFGPQZ8VSQT19K05
Click to expand...
Click to collapse
Although I can see how this GERI Delay Relay will work postponing a switch-on, but how will it delay a switch off command?
If it's a signal, it's clear it can do that. But a car unit doesn't work that way (correct me if I'm wrong). It's a +12volt means switching on and once the voltage drops to 0Volt it's going into shutdown/sleep
This GERI catches a 12V signal to switch on and another 12V to switch off. So it just sends the voltage as an impulse, if I got it right? But not that it maintains the voltage over a longer period of time.
So I don't see how it could work with a car unit?
A capacitor indeed can maintain the 12V for a longer period (depending on the capacity and frolyt, elektrolyt, etc.) it will drop eventually to 11 volts.. then 10 volts...
and then a sudden drop to 2 or 1 volts. That's basically how the capacitor works and any voltage over 9.5 or 9.8 the head unit won't consider to shut down.
I know at 8 volts it's shutting down and at 10,5 it won't shut down. Not sure exactly where the exact value is where it will consider shutdown or remain powered.
I did a project in the past where;
1) Constant voltage went into a pin
2) Switched voltage went into another pin
3) When the switch at "2" was turned off, there would still be output for a certain period of time, then it turned off.
As for the GERI not being correct; I have no reason to dispute you. I am certainly not an electrical engineer and the project I mentioned above took hours of research on my end because that is not my background at all.
I did see other boards that appear to be exactly what is needed (and cost only two bucks on ebay), but they delay shutoff to a maximum of ten seconds and seem outside the parameters of what OP needs.
As I have proven my knowledge to be well below that of other people on this thread, I'll keep quiet now.
NYCAR said:
I did a project in the past where;
1) Constant voltage went into a pin
2) Switched voltage went into another pin
3) When the switch at "2" was turned off, there would still be output for a certain period of time, then it turned off.
As for the GERI not being correct; I have no reason to dispute you. I am certainly not an electrical engineer and the project I mentioned above took hours of research on my end because that is not my background at all.
I did see other boards that appear to be exactly what is needed (and cost only two bucks on ebay), but they delay shutoff to a maximum of ten seconds and seem outside the parameters of what OP needs.
As I have proven my knowledge to be well below that of other people on this thread, I'll keep quiet now.
Click to expand...
Click to collapse
Hi NYCAR,
from your response I figure you understood me saying that I knew how it all works.
I probably didn't write correct what I wanted to ask, because I didn't actually want to say anything but my whole previous response was meant as :"QUESTION"
everything I wrote was meant as a question.. asking like:'does it do this?" or "does it work like that?"
My questions, because on the pictures I can only see a 100uF capacitor. So logically if the 12V on the input size drops, it can maintain 12V on the output only as long as 100uF will last.
Also I don't really get the AC one side and DC other side. In a car I only have DC, at least in my car.
But I doubt there are that many cars that can handle AC as normal car batteries are all DC logically.
You'd first have a DC/AC convertor
But I might just get it all wrong. That's why asking.
But I think for simplicity, the previous answer with the capacitor is the easiest part. logically current only flows through a closed circuit.
So with a diode prevent backwards current, you'll force the full ampere through the HU.
And I found, based on the technical advise from the other poster, this one https://octopart.com/ecr1ept472mff751631-jianghai-24161819
which should be able to keep the unit running for a while. If 330UF keeps the unit running for 7 more seconds, assume 5.
Than 4700 will be at least 71 seconds which is more than my 60seconds which I need as minimum.
Actually the minimum I have with mycartracks is 10 seconds but I always set it to 30 seconds so the unit doesn't think at each stop sign/traffic light, etc
that I am starting a new track. That's why I set it to 30 seconds. So when I switch off the car, I need 30 seconds for the mycartrack to understand the recording must be stopped.
than I need another 2-3 seconds to save the track and another 2-3 seconds to upload online. That's why I consider 60 seconds a safe value and with 71 seconds I'm over that
and that's based on 5 seconds on a 330uF but 330uF actually gives you 7 seconds. So I have more than enough reserves with just a little 2USD piece of hardware
As posted, the ACC doesn't really draw much Ampere so any cheap capacitor will do I guess.
But anyway thank you for pointing out the GERI! As I will buy one anyway but for another project of mine for which this device is perfect
I'm sure you explained correctly. I should have mentioned in my post that I was only stating what I meant as a way to 1) explain what I intended by my initial advice and 2) show my ignorance in electronics to hopefully forgive the fact that I posted a link to a device that you say is completely incorrect for the intended project.
NYCAR said:
I'm sure you explained correctly. I should have mentioned in my post that I was only stating what I meant as a way to 1) explain what I intended by my initial advice and 2) show my ignorance in electronics to hopefully forgive the fact that I posted a link to a device that you say is completely incorrect for the intended project.
Click to expand...
Click to collapse
And I want to say that I don't know if it's completely incorrect
Just doesn't seem to do what I intend to do. But maybe it does, that's why my questioning.
I studied some more on the device and found now this, at least that's how I assume it to work:
As far as I can tell, on the NO output you always have the DC input. So if it's 12V than it remains 12V.
You switch on 0 Volt, it goes to 0 Volt.
But you have this:'timer running' the moment DC goes to 0V
the relay will switch from the NO to the NC output so you have now 12V on the NC. So for a fraction of a second Voltage will drop to 0V.
That might be short enough for the unit to continue running but it might also be too long. So it might, that the HU still goes into power off.
But even if it's fast enough, assume that it is fast enough relaying, the timer now starts. Meanwhile, the car start is finished and I have +12V on the NO again
but the timer is running. Again a short 0V drop.
It doesn't say anywhere, that it'll now reset the timer so next time I go to 0V on the DC again (stop the car engine) the timer again gives me 30 or more seconds.
So basically, if it does reset the timer when 12+ again is on the ACC then it might work, apart from the short 0V drops during the relay switching.
To overcome the relay switching, I might put a capacitor behind the relay to handle that. But it already has a capacitor on the board, so maybe it's just for that.
But 100uF seems very few to fulfill this function. But 4000uF would be an overkill in this situation.
All in all, it might work. Problem I have with it, is that the manual/description is not conclusive to me and 100uF seems a bit few (I must admit that's just out of my stomach)
because if the relay does it's work in 0,00001 seconds 100uF will be more than enough.
Either way, I won't need a 4700uF or even 10.000uF capacitor with this solution if it resets the timer again and again each time +12V is put on it.
So that's my main question. Will the timer be reset each time +12V is on it?
Since this device is only sold in the USA, I need to know precise functionality before I order it to Europe.
I have to send it to a friend of mine in the USA who always takes care of me for US-Only deliveries and then sends it to me here in Europe.
So it's very important I know exactly what I get when I order it. Not for the money, I have enough of that. But waiting 3-4 weeks for shipments .. I don't like waiting hehehe
I'm wondering how much mA the car radio uses on the ACC?
Pure theoretical the Capacitor of 330uF has 0,0003F at 12V
and F = As/V makes As = F*V = 0.0036
If A is now let's say 20mA then 0,0036 would be enough for 0,18 seconds
if it's 2mA then it would be enough for 1,8 seconds
Above it is said, with 330uF it can keep the 12V on the unit (or 9,5 where it switches off) for 6-7 seconds.
which means the current on the ACC should be around 0,6mA?
Is that correct? (ehm, I know it should be less in reality because Voltage drops while the capacitor is unloading but just assume it keeps up for the sake of easy math, I mean it doesn't have to be exact science here just raw getting close to it)
Than a 22000uF at 12 volts with 0,6mA would be enough for, theoretical 440 seconds = over 6 minutes..
But would the ACC really be 0,6mA? I understand it's just a signal and not really powering the device. But 0,6mA?
seems a bit too few for me.
Wait let me get this straight, you guys are discussing ways of keeping from turning off when you crank the engine?
That's really complicated thinking you're doing in that case.
I'm a car electronics technician, I install all kinds of doodads in cars.
What happens is your head unit has a solid 12v coming in, noted as +30.
It also has a 12v coming in when the key is turned to acc.
The one going to your head unit likely drops when the engine is cranked.
If you want to fix that issue it's simply a matter of running a wire, with a fuse of course, 4A will do, from your car's ignition switch to your head unit.
The ignition switch has 2 'switched' 12v wires coming out, one drops to 0v on crank and the other stays up, tee the wire you're running off that, solder it up and use it to connect to your head unit's 12v switched input.
SolidusNL said:
Wait let me get this straight, you guys are discussing ways of keeping from turning off when you crank the engine?
That's really complicated thinking you're doing in that case.
I'm a car electronics technician, I install all kinds of doodads in cars.
What happens is your head unit has a solid 12v coming in, noted as +30.
It also has a 12v coming in when the key is turned to acc.
The one going to your head unit likely drops when the engine is cranked.
If you want to fix that issue it's simply a matter of running a wire, with a fuse of course, 4A will do, from your car's ignition switch to your head unit.
The ignition switch has 2 'switched' 12v wires coming out, one drops to 0v on crank and the other stays up, tee the wire you're running off that, solder it up and use it to connect to your head unit's 12v switched input.
Click to expand...
Click to collapse
I can say you're the man. That's Genius I never thought of that. It means that the Yellow Constant +12 I should get from the ignition switch the done that does not drop to 0V during starts up.?
llaugerm said:
I can say you're the man. That's Genius I never thought of that. It means that the Yellow Constant +12 I should get from the ignition switch the done that does not drop to 0V during starts up.?
Click to expand...
Click to collapse
Exactly, you connect the one that doesn't drop during cranking to the yellow wire, that usually drops low when cranking. That way the radio starts up as soon as you switch the ACC on, and not after starting the engine.
1- i had same issue. Capacitor solve my problem, and will solve yours too
Can't figure this out for the life of me. I can wirelessly charge at any time except for if I'm using wireless android auto. Is this a temperature protection thing or is it a bug?
I have a damaged USB port so I'm stuck wireless for now. Samsung S21 Ultra
I think this has nothing to do with AA, but like you already guessed with a temperature problem. My P30 Pro is also getting really hot when wireless charging + AA and after some time I put it myself out of the charging station of my car and let it cool down, but it never stopped by itself till now
I don't know where you live...but with the hot temperatures we have now in Europe I also have the temperature issue.
I could charge my phone for only 2-3 minutes before reaching more than 40°C. At this temperature the charging current goes down and in fact I lose battery level in stead of gaining battery charge.
Therefore I'm trying now the ESR charger with cooling fan. ESR calls the cooling function Cryoboost.
With this charger I can now charge the phone for 10-15 minutes until it reaches 40°C.
Afterwards I have to let the phone cool down for 3-4 minutes and then I can put it back on the charger.
As I said, I'm currently testing the ESR charger.
So far it is a lot better with an active cooling fan, but not a perfect solution.
In the past days I also had some long trips. During 2 hour trips I charged the phone for 10-15 minutes, took it off and let it cool down and then put it back on the charger. With this strategy I gained in total 10% in 2 hours.
A lot better than before, but not perfect...
Long time experience with wireless AA and long trips (Galaxy S20). This is definitely a temp issue; after few hours of traveling wireless charging stops (with phone getting pretty warm) and battery drains. As this only happens after 5-8 hours of driving (depending outside temp? Use of android?) I put a wire to charge phone in the car and when it happens (only on long rides, more than 5-6 hours continue) I put the phone on the wired charger.
Solution with charger with cooling sounds interesting - I have never heard of it. Can You put link and your experience on the thread please? Thanks!
My experience is: it is a lot better than without cooling.
Nevertheless...as long as it is warm outside you have to cool the phone down in front of an AC ventilator of the car for 3 minutes after 15 minutes of charging. This is the case at around 26-28°C or higher or when the car was outside in the sun for long time. After driving around 20-30 minutes with the AC on, the car cools down enough to leave the phone on the charger for long time.
At temperatures of 33°C and more you really have to cool the phone down every 15 minutes during driving.
If the outside temperatures are high, but there is no sun, you can just leave the phone on the charger without worries.
At temperatures below 25°C it is also no problem to leave the phone on the charger.
Moreover I made tasker scripts:
- when the phone is put on the charger, it will tell me that it is charged and the current battery level
- when the charging is stopped, it will tell me that the charging is stopped and the current battery level
- as soon as I reach a battery temperature of 39.6°C, it will tell me that the phone battery is hot
- as soon as the battery temperature drops below 36°C, it will tell me that the battery temperature is normal
Therefore I have to say, yes it is better than without a cooling fan, but the temperature issue still exists. I could raise the outside temperature until when I can charge without worries.
So far I am happy with the solution as it is possible to gain battery level on long drives.
That's a nice solution (with tasker) - but as the battery status/charging also shows up as an icon on AA I just check the icon regularly during drivingn and when it stops charging put the phone on the wired charger. Works well on the long trips.