0906 current draw

tinman

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It's slow at work and I already have the hardwire kit already wired up, so, let's take a look at the current draw of this thing. All current is on the 12V (CONSTANT wire).

First up, how does the startup current look like. Upon powering up, there is a little current spike, nothing special. Then out of the blue, the CAM suck down 1.51A of current before settling down to a steady state operation. Nothing major here, but, seriously, a 12W draw every time the CAM power up?!
upload_2017-10-17_18-1-6.png

On to the regular 1080p@30fps. Not that bad. The current is going from 150mA to 300mA. The green line is the 5V, which is pretty good. Hardly any voltage ripple.
upload_2017-10-17_18-4-56.png

Going to the 720p@30fps, the parking guard mode. I was expecting the current to go down a little, since it's doing 720p instead of 1080p, but well, it doesn't appear to be so.
upload_2017-10-17_18-7-20.png

Finally, the 720p@2fps, the parking mode without any motion detected. Well, the current peaks are still the same, but if taking the average, it does appear the current draw is less.
upload_2017-10-17_18-8-35.png
 
And just in case anyone is curious. When ACC is connected, the pin #4 is pulled LOW. When ACC is disconnected, pin #4 is pulled HIGH.
 
The current spike maybe caused by the super capacitor charging.
 
Very nice testing :D and the PS is quite clean considering it's rudimentary design ;) I'd like to see someone do this with the A119 as I'm convinced that it has a higher than usual current draw :whistle:

Phil
 
The current spike maybe caused by the super capacitor charging.
Too fast, it would need a lot more power than that, the super capacitor is capable of powering the camera for several seconds, it is probably just one of the normal capacitors charging after the internal voltage regulators turn on.

The super capacitor is supposed to take more like 10 minutes to charge.

The only difference during parking guard is the amount of time the SD card is using power for writing data. But I guess that is to be expected since it has to watch for movement. Not good if you want to leave it just recording at 2fps for a week without flattening the car battery.
 
nice testing, and I have to say you have a muuuuuuuuch better oscilloscope than us :cool::cool::cool:
 
Rayman.Chan
Could you add an option in next update to disable GPS when parking mode is activated?
I enabled position stamping in my video and I can see noise in my location when parking mode is active, for sure this is wasting a bit of current.
 
it is unable to turn off GPS power when parking, but only can disable the numners stamping.
so it is not a current saving when parking.
 
Thanks @Rayman.Chan !
I noticed that it is not switching GPS off, It would be very nice improvement for next update because car is for sure not moving when in parking mode
 
Thanks for posting these screen shots!

I'm doing a project to supply power to my 2 Mini0906's so I can mount them on my motorcycle, including one "rear" camera attached to my helmet. I came to this forum to determine what size fuse(s) I would need to protect the dashcams. That power up draw in the first oscilloscope shot freaked me out. My first though was that the 2.5 Amp fuse per Mini0906 (with both cameras) I initially had in mind would pop on powerup. Then I came across an article EE World which talked about "Dealing with Inrush" (see https://www.eeworldonline.com/key-factors-in-power-supply-selection/). The article goes on to state "The usual remedy is to temporarily introduce a high resistance between the input power and rectifier in the form of an inrush current limiter. An inrush current limiter often takes the form of an NTC (negative temperature coefficient) thermistor in series with the diode bridge and sometimes in series with the filter capacitors. The thermistor gives the filter capacitor time to charge without the inrush current fully hitting the load." So, looks like I need to slap together a thermistor/diode to protect the fuse (better make that a circuit breaker) which protects the Mini0906s. Hmmm.

The second screen shot made me wonder about circuit wear after reading the last sentence in a subsequent paragraph. "It should also be said that inrush current – or specifically, the heating that can arise from inrush current – can degrade the life of electrolytic capacitors often used as input filters. The reason is that high temperatures tend to shorten the life of electrolytic capacitors. Another factor that can cause such heating is excessive ripple current." What I'm seeing in the oscilloscope is a 100% fluctuation in draw (150 to 300 mA) approximately every 100 milliseconds, so at 10 Hz, which could simply be a low enough frequency that no significant heating, thus degredation, occurs.

I want to power the helmet cam with a battery pack. Today I did a proof of concept ride with a cheap, rechargeable, 5,000 mAh power bank from staples (https://www.staples.ca/en/tzumi-5000-mah-slim-power-bank-53060sc/product_2880764_1-CA_1_20001). The main camera, battery, and it felt like 50 feet of rear camera cable were stuffed into my front pocket, while the "rear" camera was just stuck to the top of the helmet with 3 cable guides holding the short connector down and towards the back of the helmet. Everything worked at home, but stopped working as soon as I hit the road. I'm not sure if the jostling environment of the bike caused problems with the micro USB power or the rear camera connectors. I could also be that the rechargeable battery didn't have the juice left to power both cameras....

45397

So, a couple of questions I need to answer either by experimentation or with your help. Any insights, thoughts or even more questions I need to find answers to are sincerely appreciated!

1) Is it possible to prevent the main camera from recording to conserve power? For the helmet cam, it's challenging to either mount the main camera to the bike (hardwire rider to bike) or mount it in a stable position on the rider (a chest cam for example).

2) Can I order 2 or 3 foot rear camera cables?

3) What capacity of power bank do I need to run the dual camera setup for 4 hours?

4) What would you do about that large current inrush? I better use a 2 or 3 Amp circuit breaker instead of blowing 20 fuses while experimenting eh?

5) Anyone happen to know exactly what the peak voltage and current values are? Is 5V, 2A sufficient or should I bump either of those up a bit?

I'll start a project post once I'm a bit further along. Thanks!

 
Just use a 3A to 5A fuse and forget about all the rest. It will not blow the fuse or cause any other issues. There's not enough inrush current/time involved to blow a 3A fuse; even a 2A might do OK. Even a5A fuse will protect the wiring (the fuse's only real purpose here).

There's no point in trying to re-engineer the world when a known workable and safe solution is at hand.

Phil
 
The penny drops. Since the camera is the load it's already designed to handle it. I just need to protect against a current surge on the supply side. If I'm blowing fuses I have bigger electrical system problems to work on. Thanks!
 
Fusing doesn't protect against current surge to the cam, which could possible be a problem with cams that run on 12V, but those with 5V USB power should have that protection in the power supply via it's regulation circuit ;) And I would guess that 12V cams probably have a regulation circuit inside them, but not having one I don't know for sure.

What I do know for sure is that in my 5 or so years of deep and regular reading of this site and other places, and in running several different kinds of dashcams myself, I have never heard of anyone whose cam was damaged when it was hooked up correctly to the car save for a few cases where certain cheap hardwire kits lost regulation and sent 12V to the cam instead of 5V. Good hardwire kits don't have this problem. And this amounts to several thousands of different dashcams or more :cool:

This is why I'm saying just use a 3A to 5A fuse and forget about it. There's really no need for anything more.

Phil
 
1) Is it possible to prevent the main camera from recording to conserve power? For the helmet cam, it's challenging to either mount the main camera to the bike (hardwire rider to bike) or mount it in a stable position on the rider (a chest cam for example).
- That won't be possible. Since it was designed to be in a car, low power is not a main design element. The least amount of active current draw would be to switch to 720p recording. Another possible way is to connect a switch between the CAM and power bank, so you can manually turn off the CAM when not in use.

2) Can I order 2 or 3 foot rear camera cables?
- A better approach would be to just order another cable and manually splicing it to shorten the length.

3) What capacity of power bank do I need to run the dual camera setup for 4 hours?
- Well, going by the scope shot, normal current draw averages ~250mA @5V, or ~1.25W. For simplicity sake, let's just say in one hour it would consume ~(1.25W60minutes), ~75W. Now just pick a power bank that could source that much power for 475W

4) What would you do about that large current inrush? I better use a 2 or 3 Amp circuit breaker instead of blowing 20 fuses while experimenting eh?
- I agree with SawMaster. The scope shot of the 12V was because that was the most convenient place to measurement current without desoldering some components on the CAM or stripping a USB wire. As for the spike, because it's from the 12V line, I believe that's from the DC-DC regulator from the hardwire kit that step down the 12V to 5V for the actual CAM voltage. Taking away hardwire kit, I doubt there would be that much of a spike, so just go for a simple fuse.

5) Anyone happen to know exactly what the peak voltage and current values are? Is 5V, 2A sufficient or should I bump either of those up a bit?
- That should be fine, assuming the assumption that the spike is from hardwire kit
 
1. The main camera only works when the DVR is turned on, it is impossible to turn them on or off separately, this is one single device. An additional camera is therefore called an additional one, because it is only an addition to a monoblock, which is called a DVR.

2. The manufacturer or the seller may be able to answer this question, you need to send him a request, it is unlikely that the forum will be able to solve such a narrow non-standard question except perhaps DIY.

3. Calculations for power and capacity can be carried out like this:
Normal current draw averages ~250mA @5V, or ~1.25W (0.25A*5V=1.25W)
The amount of energy needed to operate the DVR for 1 hour will be 1,25 Wh (1.25W1h=1.25), and within 4 hours - 3Wh (1.25W4h=3)
The PowerBank with a capacity of 5000 mAh (5Ah) has an energy of 18.5 Wh (5Ah*3.7V=18.5).

4. Applying a 2 or 3 Amp circuit breaker is a good solution!

5. 5V and 2A are quite enough, almost all DVRs in the world work on such parameters, do not worry if you have already been given a recommendation on this issue.
Peak values of current and voltage matter more for research purposes than for practical use and there is no need to take some extremely urgent measures to get rid of it.
Although there are DIY modules that allow you to smoothly turn on the load (in this case, this is a DVR). Once upon a time craftsmen installed such devices for smoothly turning on halogen lamps in headlamps to extend their lifespan. If you need it - you can find such a module somewhere on Amazon or ebay :)
 
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Sorry for my english© :)
Of course 1.25 Wh * 4 hours will be = 5 Wh
3. Calculations for power and capacity ...
The amount of energy needed to operate the DVR for 1 hour will be 1,25 Wh (1.25W1h=1.25), and within 4 hours - 3Wh (1.25W * 4h=3)

PS: And at the same time, the energy of a car battery, for example, with a capacity of 62 Ah, is 744 Wh (62Ah * 12V = 744), and even if you use only 10% of this capacity (and this will be 74,4 Wh), it is still quite a lot.
The volume of such energy - 74,4 Wh is comparable to the energy of a 20000 mAh Power Bank (20 Ah * 3.7V = 74 Wh).
 
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1) Is it possible to prevent the main camera from recording to conserve power? For the helmet cam, it's challenging to either mount the main camera to the bike (hardwire rider to bike) or mount it in a stable position on the rider (a chest cam for example).
maybe you can consider K2S, both the remote cameras have cables, and you can only use the CAM1

2) Can I order 2 or 3 foot rear camera cables?
K2S have 2 meters short cable for motocycle use.

3) What capacity of power bank do I need to run the dual camera setup for 4 hours?
5V*0.5A*4hours/80%/3.7V=3000Ah, so a 5000mAh power bank will fill you but must be a good quality one.

4) What would you do about that large current inrush? I better use a 2 or 3 Amp circuit breaker instead of blowing 20 fuses while experimenting eh?
3A fuse fuse is much more than needed. we use a 24V3A PTC fuse in 0906 cigar charger and there is 0 negative feedback.

5) Anyone happen to know exactly what the peak voltage and current values are? Is 5V, 2A sufficient or should I bump either of those up a bit?
I think it is input Aluminum Electrolytic Capacitor recharging. it is around 5mS, will not impact fuse.
 
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