Questions tagged [apple]

28 questions
34
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1 answer

How do volume control headphones work?

A recent question over on Android Enthusiasts got me to wondering how volume control headphones work. I don't mean volume control which works by attenuating the incoming signal, but the kind of volume control that signals to the device to increase…
Mark Booth
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2 answers

How Macbook Pro detects an external microphone through TRRS jack?

An audio port on a MBP is a combination output. If you plug in 4-conductor 3.5mm connector (TRRS) like the one on Apple earbud with microphone, it appears that that port can be use as an input. I just bought a bare male TRRS audio jack. (without…
5argon
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4
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3 answers

Understanding the Apple 1 power supply

I'm trying to understand the schematic of the Apple 1 computer power supply. Nothing surprising at first sight. Two power transformers (117 VAC -> 10 VAC / 117 VAC -> 28 VAC), two diode bridges, and four voltage regulators (+5V / -5V / +12V /…
Macmade
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3
votes
2 answers

On an Apple 12W USB Charger, how are the D+ and D- lines configured?

Looking for the voltages on the V+ and V- lines of an Apple 12W charger that corresponds to the 2.4A output.
mmize
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2
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2 answers

Trouble simulating an instrumentation amplifier on KiCad

So... I'm trying to build an EMG sensor for biofeedback purposes, but I'm having loads of trouble both on the breadboard and on the CAD side as well. I'm using a M1-processor mac mini which could be a problem regarding ngspice. Please note that I'm…
2
votes
1 answer

Apple devices - "Vibrating feel" when charging

I am absolutely not experienced when it comes to electrical stuff at all which is why I hope you can help me out on this one because I am a bit worried right now. I own a bunch of Apple devices and after making the switch to a new 2017 MacBook Pro I…
2
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0 answers

How to interface with the Apple Watch for the purpose of accessing its internal memory?

Unlike other apple products which can be directly connected to a PC via USB, the Apple Watch is completely wireless from the point it exits the factory, as far as I am aware. Aside from a 6-pin diagnostic port under the watches strap I am unaware of…
Kris
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2
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1 answer

What is the purpose of this transistor in an Apple Time Capsule?

While taking apart a 2009 Apple Time Capsule, I found a 2N3904 NPN transistor on a 2-wire cable with the emitter connected to one wire and the base and collector connected together and to the other wire. The transistor was physically attached to the…
3871968
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How are Mac AC adapters compatible when they are different voltages?

I recently had my Mac AC adapter die on me, so I just cut the end off and soldered it on to an old Lenovo AC adapter I had laying around. Since they are both 20V AC adapters, it works fine, but I am trying to understand how the AC adapters actually…
Saaif
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2 answers

Did my wireless charger melt because of another wireless charger nearby?

I got home today and immediately smelled burnt plastic. I discovered that an Apple Watch charger burned and melted (every part of the charger is original Apple.) See included photos:…
1
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0 answers

Suitable Replacement RIFA Capacitors for Apple IIE PSU

I have an Apple IIE that I'm trying to bring back to life and in my research, everything suggests replacing the RIFA capacitors in the power supply. I'm looking for suitable replacement RIFA capacitors and wondered if anyone can tell me if I'm…
1
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1 answer

Macintosh Classic video input

I want to modify or rebuild the video amplifier circuit of the Macintosh Classic so that it accepts 8 bit grayscale input. Original circuit accepts 1 bit 5V P-P video signal. First idea was just to supply it with 0-5V output from a DAC. I am not…
Farid83
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How to get working "specs" of iMac fans from logic board schematics?

I would like to salvage these three fans They come from an Apple iMac 17-Inch "Core 2 Duo" 2.0 (Late 2006 - iMac5,1 - A1208 - 2114) CPU Fan Apple Service Source P/N: 922-7641 Apple P/N (on sticker): 603-8690 Manufacturer P/N: BFB0712VHD Voltage…
1
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0 answers

How to determine proper capacitors to replace a battery for an Apple Magic Trackpad 2?

I have several Apple Magic Trackpad 2 devices and am finding that the batteries routinely go bad on these. They swell and deform the trackpad such that it doesn't stay flat with the desk / tray surface and thus out of fear of fire, etc. I removed…
ylluminate
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1 answer

How does Apple's ADB's collision resolution work?

I've read several different documentation sources explaining how Apple's asynchronous ADB protocol works. Although quite convoluted, it makes some sense of several rereads. I am having difficulty wrapping my head around how ADB's collision…
user148298
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