How to Downgrade iOS 11 to iOS 10.3.3 on iPhone and iPad

06/10/2017 Categories: Constructeur, Logiciel Tags: , Comments off

Don’t like iOS 11 on your iPhone or iPad? You can downgrade to iOS 10.3.3 if you act quickly. Maybe you don’t like the update, maybe you find iOS 11 battery life to be poor, or app compatibility to be a problem, or perhaps you think the performance is subpar. Whatever the reason, you can easily downgrade iOS 11 if you need to, but the ability to downgrade is only available for a limited time while Apple continues to sign the prior operating system release of iOS 10.3.3.

We’ll walk through how you can downgrade iOS 11 back to iOS 10 on an iPhone or iPad.

This guide requires iTunes and a computer, internet access, an iOS 10.3.3 ISPW file, and a USB cable. There is no way to downgrade iOS 11 without iTunes and a computer.

Important note: downgrading iOS 11 to iOS 10.3.3 can cause data loss, including the removal of important data or everything on your iPhone or iPad. Thus it is critical to have a backup that is compatible with iOS 10 available before downgrading (one should have been made prior to updating to iOS 11 in the first place), this is because iOS 11 backups are not compatible with iOS 10 or other prior releases. If you only have a backup for iOS 11, then downgrading to iOS 10 may require you to update again to iOS 11 in order to restore from that iOS 11 backup. If you don’t know what you are doing and do not have adequate backups, do not attempt to downgrade or you may experience permanent data loss on the iPhone or iPad.

We’ll cover two ways to downgrade, a simple way that should work for most users, and an approach that requires Recovery Mode if the first downgrade method fails.

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Categories: Constructeur, Logiciel Tags: ,

How to Download a Full macOS High Sierra Installer App

04/10/2017 Categories: Constructeur, Logiciel Tags: , , Comments off

Many Mac users who are attempting to download macOS High Sierra from the Mac App Store will find that a small 19 MB version of “Install macOS High Sierra.app” downloads to the /Applications folder of the target Mac, rather than the complete 5.2 GB Installer application for macOS High Sierra. This is annoying because it prevents a single download from being used on multiple computers, plus the small installer requires an internet connection during usage to download the rest of the High Sierra update files. Additionally, the tiny 19 MB incomplete installer prevents users from being able to create a macOS High Sierra USB installer drive or other custom update options available through the command line, like skipping the APFS update.

This tutorial will show you a workaround trick that allows Mac users to download the full macOS High Sierra “Install macOS High Sierra.app” file at 5.2 GB with the complete installer tool set and all dmg files and associated Install macOS High Sierra.app/Contents/Resources/ tools, rather than the tiny incomplete truncated installer at 19 MB.

How to Download the Full “Install macOS High Sierra.app” Application

Warning: this method relies on a third party tool from an unverified third party source, if you are not comfortable with using unvetted and unverified software, and if you do not understand the risks associated with using potentially dubious software, do not follow this process. This is for advanced users only.

    1. Go to dosdude1.com here and download the High Sierra patcher application*
    2. Launch “MacOS High Sierra Patcher” and ignore everything about patching, instead pull down the “Tools” menu and choose “Download MacOS High Sierra”

    1. Confirm that you want to download the complete macOS High Sierra install application, and then point it to a location to save on the local hard drive

    1. The patcher app will notify you when the download is complete, when it is done downloading quit out of the patcher app

    1. Locate the “Install macOS High Sierra.app” file you downloaded, it will be the complete installer application with the full Contents/Resources/ toolkit available

* The “macOS High Sierra Patcher” application is intended for those with unsupported Macs and Hackintosh users, but any Mac user can use the app to be able to download the complete installer file from Apple servers. The source of this patcher application is a MacRumors Forums

You can confirm that you have the complete Install macOS High Sierra.app application by getting info on the file, the complete installer should be around 5.2 GB rather than the tiny 19 MB incomplete installer that requires additional downloads.

The complete macOS High Sierra installer downloaded

Why do some users get a small incomplete version of macOS High Sierra installer from the App Store?

This is not yet known, but it happens with the final version of macOS High Sierra installer as well as with some of the beta versions.

It is unclear why some users will get a 19MB version of “Install macOS High Sierra.app” when downloaded from the App Store, while others users will get the complete 5.2GB version of “Install macOS High Sierra.app” when downloading from the App Store. Interestingly, once a user ends up with the 19 MB version of the incomplete installer, that seems to be the only thing that will download for that user regardless of how many times the incomplete installer app is deleted and re downloaded.

Incomplete macOS High Sierra installer

The installer size and completeness inconsistency appears random, and has no relation to disk space, beta enrollment, software catalog, and other theories seem to be incorrect as well.

Categories: Constructeur, Logiciel Tags: , ,

How to Disable or Enable Auto-Brightness in iOS 11 for iPhone and iPad

04/10/2017 Categories: Constructeur, Logiciel Tags: , Comments off

Auto-Brightness is a screen setting on the iPhone and iPad which causes the device to automatically adjust the display brightness depending on ambient lighting conditions. For example, if you’re outdoors or in bright lighting, the screen would adjust to be brighter so that it is more visible, and if you’re in a dim room or outdoors at night, the screen would adjust to lower the brightness so that the screen isn’t as glaringly bright. Auto-brightness in iOS also can improve battery life by adjusting the brightness of the iPhone or iPad display down as the ambient lighting permits.

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Categories: Constructeur, Logiciel Tags: ,

People or Object counter Circuit diagram using IC 555 and IC 4026

26/06/2017 Categories: Électronique, Matériel Tags: Comments off

People / Object counter circuit have a wide variety of applications in Banks, Hospitals, factories etc. This project focuses on building an effective counter using IR as a sensing element and capable of counting from 0 to 999. This project uses Two simple IC’s ( IC 555 & IC 4026 ) with IR transmitter and Receiver to detect the incoming people/object.

This Project comprises of Three parts

  1. IR Transmitter
  2. IR Receiver
  3. 7 Segment drivers

IR TRANSMITTER:

Freq = 1.45 / ( R3 + 2R1 ) C2IR transmitter was wired around Astable multivibrator using IC 555. As we all know that multivibrator produce square wave pulses and we gotta fix the frequency of the output signal as 38 Khz since we are about to use TSOP 1738 an Infra red sensor which is capable of detecting signals of 38 Khz. The frequency of the astable depends on R1,R3 and C2. So lets do some math

         = 1.45 / (470 + 2 * 1690 ) * 100 * 10

         = 37.6 Khz

So we have fixed the IR frequency of 38 Khz and now Transmitter part is done.

Please note that i have used a simple IR transceiver module (brown board  – right top) for this project to make things simple. You can use use IR module like i did if you have any. If not build the IR transmitter using IC 555 as shown in above circuit. The receiver part was given in the below circuit diagram.

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Categories: Électronique, Matériel Tags:

Residual-current device

21/06/2017 Categories: Matériel, Sécurité Tags: , Comments off
From Wikipedia, the free encyclopedia
« GFCI » and « Trip Switch » redirect here. For the financial center ranking, see Global Financial Centres Index. For the song, see Trip Switch (song).
A residual-current device (RCD), or residual-current circuit breaker (RCCB), is a device that instantly breaks an electric circuit to prevent serious harm from an ongoing electric shock. Injury may still occur in some cases, for example if a human falls after receiving a shock. In the United States and Canada, the device is more commonly known as a ground fault circuit interrupter (GFCI), ground fault interrupter (GFI) or an appliance leakage current interrupter (ALCI). In the United Kingdom, these are better known by their initials RCD, and a combined RCD+MCB (miniature circuit breaker) is known as a RCBO (residual-current circuit breaker with overcurrent protection). In Australia, they are sometimes known as safety switches or an RCD. An earth leakage circuit breaker (ELCB) may be a residual-current device, although an older type of voltage-operated earth leakage circuit breaker also exists. In German-speaking countries the device is sometimes known as FI where the F stands for fault (Fehler) and I for the symbol that represents electric current.
 
These electrical wiring devices are designed to quickly and automatically disconnect a circuit when it detects that the electric current is not balanced between the energized (line) conductor(s) and the return (neutral) conductor. Under normal circumstances, these two wires are expected to carry matching currents, and any difference can indicate a short circuit or other electrical anomaly is present, such as leakage. Leakage can indicate a shock hazard (or shock in progress) which is a potential danger to a person. Current leakage can result in harm or death due to electric shock, especially if the leaking electric current passes through the torso of a human. A current of around 30 mA (0.030 amperes) is potentially sufficient to cause cardiac arrest or serious harm if it persists for more than a small fraction of a second. RCDs are designed to disconnect the conducting wires quickly enough to prevent serious injury from such shocks, commonly described as the RCD being « tripped ».

An RCD does not provide protection against unexpected or dangerously high current (called spikes or surges) when current is flowing in the usual wires in the circuit, therefore it cannot replace a fuse or protect against overheating or fire risk due to overcurrent (overload) or short circuits if the fault does not lead to current leakage. Therefore, RCDs are often used or integrated as a single product along with some kind of circuit breaker, such as a fuse or miniature circuit breaker (MCB), which adds protection in the event of excessive current in the circuit (the resulting RCD with overcurrent protection called an RCBO). RCDs also cannot detect the situation where a human accidentally touches both conductors at the same time, since the flow of current through an expected device, an unexpected route, or a human, are indistinguishable if the current returns through the expected conductor.

RCDs are usually testable and resettable devices. Commonly they include a button that when pressed, safely creates a small leakage condition, and a switch that reconnects the conductors when a fault condition has been cleared. Depending upon their design, some RCDs disconnect both the energized and return conductors upon a fault, while others only disconnect the energized conductor and rely upon the return conductor being at ground (earth) potential. The former are commonly known as « double-pole » designs; the latter as « single-pole » designs. If the fault has left the return wire « floating » or not at its expected ground potential for any reason, then a single-pole RCD will leave this conductor still connected to the circuit when it detects the fault.

[one-third-first]A two-pole, or double-pole, residual-current device. The test button and connect/disconnect switch are colored blue. A fault will trigger the switch to its down (off) position, which in this device would disconnect both conductors.[/one-third-first]
[one-third]

  • Log-log graph of the effect of alternating current I of duration Tpassing from left hand to feet as defined in IEC publication 60479-1.[1]

[/one-third]
[one-third]

1: Electromagnet with help electronics
2: Current transformer secondary winding
3: Transformer core
4: Test push-button
L: Line conductor
N: Neutral conductor

[/one-third]

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Categories: Matériel, Sécurité Tags: ,