Reading VHS, S-VHS tape through a VCR?
 

1. Does any of you know how the VCR knows about when the tape ended up scrolling to the very beginning and that it no longer has to scroll it further or that it is already the end of the recording and doesn't have to pull it anymore, "read on" ?
How is it that these transparent tapes glued at the beginning and its(tapes) end aren't torn out by the VCR ?

2. Does the locking brake in the VHS cassettes manual tape rewinding (the possibility of unlocking by pressing on the hole on cassette) must be functional (must block) so that the VCR read and play the VHS tape correctly ?

3. Does the VHS cassette flap lock, which rises(flap) when you insert the cassette into the VCR, to reveal access to the tape, must be mounted (must there be a blockage that can be unlocked by pushing in its proper place, and which can even be removed completely) ? Does it not have to be (among other things to be played by a VCR) and then you can open the flap in the VHS cassette at any time without any lock ?

The transparent piece is just a leader. It's tucked into the spool, and the bonded to the tape at the other end. Most VCRs just feel it stop moving, and is really the same concept (in reverse) as a garage door opener re-opening when it detects an object. That's also why tape issues can cause a VCR to stop playing, especially when a tape is sticky.

The brake is controlled by either FF/PLAY or REW.

The tape gate ("flap") opens with the button on the side next the gate. When inserted, in one motion, several things happen in the VCR. Pushing the button to open the gate is one of those actions. If the gate is missing, it doesn't matter for playback. The gate is just there to prevent debris from getting on the tape, and thus the VCRs head (and then causing damage).

Thank you for the answers and information.

But this brake must be functional (must block tape in cassette) so that the VCR read and play the VHS tape correctly ? Or it(brake) is not necessary and this brake can be remove ?
I think it's the most important that the tape is not blocked so that releasing the brake will not help unlock it. Hence, I think that the brake is not necessary for the VHS cassette to function properly in the VCR, but as it really is, I don't know.

There is a hole on the bottom of the cassette. In the VCR pokes in and lifts the brake away from the spools. The brake is not needed for the cassette to work, but if it's not there it makes it easier for the tape to hang loose and risk getting crumpled when inserted into the VCR.

There is an infrared LED in the VCR that pokes up behind the tape and two sensors at the side of the cassette. If the cassette is at the start or end, the led will shine through the clear leader and the sensor on the respective side will pick it up.

Attachment 10415

(Images borrowed from the VCR repair faq.

There may be additional sensors looking at or sensing at the spools to help fast forward etc.

Thank you.