Does the new ipad use pulse width modulation to control the brightness of the display?

Does the new ipad use pulse width modulation to control the brightness of the display? I have photophobia and migraines and am unable to use displays that use this technology due to it triggering a headache.

You'll have to go to an Apple Store and view the screen to see if it's OK for you. If a store is not convenient, buy one from Apple online and check it out. You have 14 days to return it for a full refund, no questions asked.

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Using pulse width modulated signal (square wave) to control when a signal is turned on or off

Using pulse width modulated signal (square wave) to control when a signal is turned on or off
Greetings All
I'm trying to use a labview created pulse width modulated signal (square wave) to control when a signal is turned on or off.
Here's my logic and graphic example:
1) The source wave signal is continuous
2) Use a PWM (square wave) created in labview to control when the signal is turned on or off
3) If PWM signal (amplitude) is greater than 0 play signal if PWM is not greater than 0 don't play signal.
I'm actually using this to step sequence / pulse several separate magnetic coils using my audio card (which has several audio output channels), I have a signal in labview played constantly. Than compare it to the PWM (square wave) which controls if the signal gets played on each separate channel or not. That way I can control which coil is on and off and in what sequence they are activated.
I couldn't find an edge detection for a square wave created in labview so I tried Limits but that doesn't seem to work unless I change the phase manually and that only goes from 1 to -1. I'm just trying to compare the PWM (square wave edges) already created by labview / play a signal if the pulse is greater than 0 and it turns off the signal if it's less than 0.
Should I be doing this another way
Tia
Message Edited by sal22 on 08-16-2009 06:09 PM
Message Edited by sal22 on 08-16-2009 06:10 PM
Solved!
Go to Solution.
Attachments:
PWM control signal block.png ‏23 KB
PWM control signal front.png ‏48 KB
pwm test.vi ‏36 KB

Greetings,
I tried it two ways using amplitude and levels and fft spectrum. The values don't seem to update the way I need them to (basiclly showing a 0 or a 1). I compare the Y values like you recommended but they don't ever seem to update.
tia
Message Edited by sal22 on 08-19-2009 10:05 AM
Attachments:
pwm magnitude not updating.png ‏29 KB
pwm test.vi ‏41 KB

Throttle body PID control using pulse width modulation

Hello all,
I am trying to do a PID control for a throttle body (using pulse width modulation) for a set value of feedback voltage. The process variable is the pulse width duty cycle. The throttle body is expected to be fully open at a feedback voltage of 5V and pulse width duty cycle of 42.5%. When I use the highlight execution using the attached file, I can see the throttle body fully open (the values observed are: PID output 42.5 %, feedback voltage approximately 4.7V). However, when the highlight execution is unclicked, the throttle body flutters in the closed condition (still PID output 42.5%, feedback voltage approximately 0.9 V). Can any one please help by suggesting any modification to this attached file to make this throttle body respond to the set value of feedback voltage.
Many thanks
Ajith
Attachments:
Throttle body control using PWM technique - PID.vi ‏525 KB

How did you determine your P, I, and D gains? If you have not tuned your controller, you'll get poor performance. Running with execution highlighting will slow down the execution, which will change the effect of the gains. I would start with pure proportional control (I and D = 0) with a small proportional gain, and see if it responds in approximately the way you want. If so, then your code is probably correct, and you just need to do a full tuning to get good performance. There are many resources available on the web, on this forum and elsewhere, for PID tuning. Note that since your code uses a simple PID example, and not the one from the PID toolkit, the gains do not have the units that are used in many tutorials so you'll have to correct the calculations to compensate.

Lenovo x240 and PWM (Pulse Width Modulation)

Hello everyone!
Does Lenevo Thinkpad x240 use PWM (Pulse Width Modulation) to control screen brightness?
If so, is there a flickering effect like in this video?
https://www.youtube.com/watch?v=SpDdy9jSx7Y

There is an analog modulation with which there is no pulsation at low brightness levels. For example, HP Elitebook 8740w. Watch video: http://www.youtube.com/watch?v=Dk4ckdQ9rvE
How poor the implementation of PWM (if x230 has PWM) is in this model?

Does the new iPad use Nanosys QDEF display technology?

I was wondering whether the new iPad uses Nanosys QDEF display technology in its Retina Display?

I don't usually have bad luck, though iPads seem to be the exception. I had two iPad2 with screen flaws before I gave up and decided to hold out for the iPad 3. My iPad 3 has the yellow on one side and uneven lighting. I bought my wife one yesterday because she wanted on in spite of the problems I am having. Hers is perfect, except for two dead pixels right in the middle of the screen. But the screen is uniform with no yellow, and there's no overheating or anything like that.
She is considering keeping it in spite of the dead pixels. Stuff like that doesn't bother her, I guess.

My itunes on windows7 pc does not recognize new ipad. using same cable and usb port that works for my ipod. what to do?

My itunes on windows7 pc does not recognize new ipad. using same cable and usb port that works for my ipod. what to do?
Thanks

Have you updated iTunes with the absolute latest software? If you have not in a long time, your iPad won't be recognized.

Samples Not Acquired on NI 660x or NI 6624 Devices When using pulse width, semi-period or two-edge separation buffered measurements with the NI 660x and NI 6624 on counters 0 and 1, some samples may not be acquired under certain circumstances.

In the DAQmx 9.4 Readme the following is stated:
Samples Not Acquired on NI 660x or NI 6624 Devices When using pulse width, semi-period or two-edge separation buffered measurements with the NI 660x and NI 6624 on counters 0 and 1, some samples may not be acquired under certain circumstances.
Could anyone elaborate on this? I am particularly interested in knowing under what circumstances this problem arises for the 6602 PCI devices.
How should I understand 'NI 660x and NI 6624 on counters 0 and 1'. Is it only a problem on counter 0 and 1 for the 660x or does this only apply for the 6624 devices.
/mola

Are there any NI Product Support Engineers out there who has an answer to this question and who are willing to share it with me?

Problem with setting up new Ipad Air2:I can't set up my new Ipad using new Apple ID and it keeps showing the notification that wrong email or password and try again. I can log in Itune with thesame

I can't set up my new Ipad using new Apple ID and it keeps showing the notification that wrong email or password and try again. I can log in Itune with the same ID. Please help me if you have come across the same issue. Thank you!

Contact the App store for Apple ID help. Their support link is on the right of the App store window
LN

HT201269 Is it recommended to set up a new iPad using the back up from iPhone?

Is it recommended to set up a new iPad using the back up from iPhone?

Just copy the library over to the new drive?

Got a replacement Ipad backed up the old one in the cloud but when I try to sign in with the new Ipad using my apple Id it says there are no backups avaiable

I got a replacement I pad for a damaged on- The old Ipad was backed y up in the cloud and verified on all my devices. When I activated my new Ipad using my apple ID and tried to restore backup it said none was available what can I do?

Restore from iCloud Backup; new iPad start at step 4.
1. Erase all contents and settings (Settings>General>Reset>Erase all content and settings)
2. You'll be asked twice to confirm
3. You'll see Apple logo and progress bar
4. You'll see a big iPad logo on screen
5. Configuration start
6. Set language
7. Set country
8. Enable Location Service
9. Select network, enter password and join network
10. You'll be given 3 options (a) Setup as New iPad (b) Restore from iCloud Backup (c) Restore from iTune Backup
11. Selected Restore from iCloud Backup
12. You'll be required to enter Apple ID and Password
13. Agree to Terms and Conditions
14. Select Backup file
15. You'll see progress bar
16. Red slider will appear; slide to unlock; step #1 to #16 is fast
17. Pre-installed apps will be restored first
18. Message: Purchased apps and media will now be automatically downloaded
19. You'll see a pageful of apps with Waiting/Loading/Installing
20. Message: Some apps cannot be downloaded, please sync with computer

I'm trying to prepare some new iPads using Apple Configurator and the download of IOS8 failed. The error in Apple Configurator is "Unable to download iOS 8.0. The firmware image was corrupted. Please retry the operation."

I'm trying to prepare some new iPads using Apple Configurator and the download of IOS8 failed.
The error in Apple Configurator is "Unable to download iOS 8.0. The firmware image was corrupted. Please retry the operation."
Is there a way to get the Apple Configurator to try to re-download iOS 8?

Apple Support had me delete the image file from the following location:
~/Library/Containers/com.apple.configurator/Data/Library/Caches/com.apple.confi gurator/firmware/
The file name was iPad3,4_8.0_12A365_Restore.ipsw
I deleted this file and ran the prepare again and it download the iOS 8 ok and successfully prepared the iPad.

Cannot Find Pulse Width Modulation(FPGA, Use in SCTL)

Hello All,
Can someone tell me where I can find Pulse Width Modulation (FPGA, Use in SCTL).vi? I couldn't find it in LabVIEW Example Finder.
Thanks
Message Edited by John Edwards on 02-01-2009 09:30 PM
Solved!
Go to Solution.

Here it is...
Attachments:
Pulse Width Modulation (FPGA, Use in SCTL).vi ‏43 KB

My old pc with my music does not come up with device when I connect y new iPad using USB

My old pc with my iTunes music library does not see a device when I connect new iPad using usb

iPad not appearing in iTunes
http://www.apple.com/support/ipad/assistant/itunes/
iOS: Device not recognized in iTunes for Mac OS X
http://support.apple.com/kb/TS1591
iOS: Device not recognized in iTunes for Windows
http://support.apple.com/kb/TS1538
IOS: Syncing with iTunes
http://support.apple.com/kb/HT1386
Apple - Support - iPad - Syncing
http://www.apple.com/support/ipad/syncing/
ITunes: Syncing media content to your iOS devices
http://support.apple.com/kb/ht1351
 Cheers, Tom

Pulse width modulated signals

Is it possible to generate a fixed frequency with variable duty cycle signals using counter/timer channels of my DAQ 700?
If yes, is there any example I could download?
If no, I am looking for a DAQ card that can handle
the job, I'd appreciate any recommendation.
Another part of my project is to read in a analog signal while generating this pulse width modulated
signal. So far I am not very lucky with one DAQ,
I am thinking of getting two. Does it sound overkill?
Please help.
Thanks

Could you provide a timing diagram for your digital signal?
I am a firm believer that a digital output device such as an NI timer can create any signal, given the proper software or hardware. I once did a high speed, gated, triggered data acquisition with only a single NI timer chip on the AT MIO 16E-1. It required about 75 feet of BNC cable, more PFI wires than you can imagine, four external logic devices (AND and OR, NAND and NOR boxes) all interconnected and basically tangled. I don't think I could repeat that setup without my documentation, but the point is, it worked.
The most important thing from that example is that I used a timing diagram. These are so vital in digital IO and timer applications that its not funny.
If you can't determine ho
w to do what you need from a timing diagram, just send me a copy, let me know what the basic specs are of the DAQ 700 (how many counters, interconnect capabilities, etc) and I can try to help.
Good luck.
As far as reading the analog signal at the same time...well, look at my example. I generated the trigger/gate signal with the card, and then read in the analog data (on several channels simultaneously.)

Pulse width modulation with daq mx

Im trying to change the pulse width modulation on the fly with daq mx. All I have found so far are examples useing traditional DAQ, but not DaqMX. It would be a lot easier if I were to use DaqMX since I will be useing other daq applications in my program and would rather use mx.

Does this help?
Attachments:
PWM-Counter_Output_Folder.zip ‏63 KB

Does the new ipad use pulse width modulation to control the brightness of the display?

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