Not past tense but past participle always?

Hi. Would you say that the kinds that I am trying to work with (if you get what they are by the examples below) are things that suppose to be either present or past participle and not a past tense (although some might look like participles in form)? Are words in bold letters all past participles? And for these kinds of phrases, do you think no past tenses should be used?

Stranded in an island where there seemed no one inhabiting, he tried to contact someone to help him.

Equipted/Armed with pens and pencils, he went to the test site to take the test.

Touched by his generosity, he felt good all the way home.