In portable CD players, exactly how is it that the Anti-Skip Protection, (or Electronic Shock Protection, or G-Protection) works?
My current hypothesis is that it records the allotted time (Anywhere from Ten to Forty Five seconds worth) of a song, and is able to detect when the laser skips the CD.
As a side note, Sony boasts their G-Protection as working even better…Does anyone have any clue, or are they just marketing the same skip protection under a new name to sell more units?
http://www.epinions.com/elec-review-9DD-2562E855-3A38DF18-prod2
TeChNiCaL Stuff, How G-Protection Works
G-Protection works in two components, physically and through a memory buffer. The physical part is always “on”, even when G-Protection is turned off, and helps to stabilize the laser, ensuring smooth playback. The buffer part comes into play when G-Protection is switched on and stores up to 40 seconds of music in case the physical aspect of G-Protection fails. The memory also works to conserve battery by having the laser read ahead for about 10 seconds, shut off, and that read another 10 seconds. This way, the laser is not on all the time, conserving a small amount of battery. Ok, so I’m sure that there is more to it, but this is a simple explanation of how it works.
That pretty much clears it up for me. I never considered the Anti-Skip time was limited to conserve battery life, that makes a lot of sense.
Actually…that’s not really how G-Protection, or any form of CD Anti-skip protection work. What happens, is the when you turn on the buffer form of anti-skip, the motor speeds up, and starts reading information from the cd at a faster rate than normal. Instead of sending it straight to the headphone jack, it first sends the musical information to a memory buffer. That’s why the music stops for a second if you turn anti-skip on in the middle of a song. When the buffer is full, it contains the advertised amount of music in it, rendering the cd player “skip proof” for that amount of time. However,
is simply not true. If it worked this way, then the cd would skip quite easily if you managed to shock it just before the buffer was due to refill. Instead, the laser is constantly reading, and constantly making sure the buffer is full. In reality, using anti-skip actually decreases battery life. Running that motor faster eats up more battery life.
Hope this helps
Why does my cd player turn on w/ the anti skip protection off? To conserve power? or just to annoy the $#!+ out of me?
Which model do you have?
Some models just start up with a specific set of defaults.
Mine personally starts with the x-bass enabled. Ticks me off too.
It might be because of the conserving power reason though. Usually turning off the anti-skip can give you a lot more battery life. When manufacturers quote battery life on the packaging, it’s almost always with anti-skip turned off.
While I agree with most of your post, I think that once the buffer is full, the CD will read at normal speed (becuase the buffer empties at regular speed, the sound isn’t played back faster) therefore the additional battery drain is not caused by the CD constantly spinning faster, but rather the power required to use the memory in the CD player.
There…I was looking all over for something to cite…Finally found it.
From Notes on the Troubleshooting and Repair of Compact Disc Players and CDROM Drives
So, we derive from this that while the cd player’s anti-skip is on, the motor is running at a higher speed, and this is the main cause of the added power drain.
The way to tell that it constantly stays at a higher speed is to listen. You don’t hear the motor spin up or down at all. IF you’ve got a window on the top of the cd, you should notice a basic uniform speed.
Yes, it seems you are correct, I don’t recall seeing the CD spin up or down, so it must be constantly running at a higher speed. The question is why? I would think it would save power to only run at 2x while filling or refilling the buffer, but to go back to 1x under normal circumstances. Perhaps changing the motor speed cuases even more of a power loss.