Please email me the spec for MC7909CT and MC7924CT. I can't seem to locate these spec from vishay website. Is fairchild the same as vishay? Please kindly advise. Thanks.
MC is Motorola. Many manufacturers produced regulators with same number. Most of case the first letters: manufacturer's code. (LM= National, KA=Samsung etc.)
These are common, garden variety, "everybody makes one" negative voltage regulators. As Sebi pointed out, the first letters represent the manufacturer.
Using www.google.com , type in MC7909CT , and dozens of pages are returned. Most with spec sheets.