When I was a kid we had a television that used an ultrasonic remote. Not quite like this one though, ours did use batteries. But, similarly, it was dead simple with only three buttons. One for on/off volume (each time you clicked it the TV would reduce in volume with three distinct settings, then the fourth click would turn the TV off) and the other two for ‘channel up’ and ‘channel down’. The TV’s mechanical tuner would very audibly ‘chunk, chunk, chunk’ up or down each time you hit the button.
And yes, our dog hated it as he could hear the ultrasonic signal, and yes, jangling keys near the TV could cause it change volume, turn off or on, or the channel to change.
When I was a kid we had a television that used an ultrasonic remote. Not quite like this one though, ours did use batteries. But, similarly, it was dead simple with only three buttons. One for on/off volume (each time you clicked it the TV would reduce in volume with three distinct settings, then the fourth click would turn the TV off) and the other two for ‘channel up’ and ‘channel down’. The TV’s mechanical tuner would very audibly ‘chunk, chunk, chunk’ up or down each time you hit the button.
And yes, our dog hated it as he could hear the ultrasonic signal, and yes, jangling keys near the TV could cause it change volume, turn off or on, or the channel to change.