Canon QL19 and QL25 use trap needle for shutter priority auto exposure. The metered manual can also be used. Konica Auto S2 is another trap needle shutter priority auto exposure camera. Konica Auto S2's trap needle mechanism is more complicated. They are all mechanical which something I like over electronic cameras.The meter needle is used for opening the right f stop opening.
The aperture priority camera from this period used electronics. The most famous one is Yashica Electro 35. I will post this repairs later on.