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Could be the 1970s version of The Tomorrow People, later episodes of which had the main characters use wrist devices called "jaunting bands" to control their teleportation (in earlier episodes they used belts). The term "jaunting" for teleportation was a shout-out to Alfred Bester's novel The Stars My Destination. I believe the series did feature the occasional time travel story.
Edited by Aspectifer
Might also be The Girl From Tomorrow/Tomorrow's End. I'm only going from memory myself but it seems to fit.
Better dead than smeg.
Seconding The Tomorrow People as a suggestion. There's a scene with a bridge like you describe in the first episode.
(Definitely not The Girl from Tomorrow.)
Live-action, right?
I seek the name of a TV-Serial for children/Teens from ´80s:
Some children, maybe with an adult as leader, are able to teleport and/or time travel. I think that they are using a wristband.
In one scene, one or more of the children jump of a bridge and disapeer i a bright oval light. It could be a British show. I think that in one episode they go back i time to the middel age and help some local kids.
I know that is not much to go on.
Thanks,
René