Saturday, October 20, 2012

Relative Clock/Timer/Alarm


Towards the end of the '80s, when I started out in electronics, one day I decided to make a special alarm clock: one, that, when the time comes, switches on some device in my room - be it a radio, TV or anything else. At the time microcontrollers were not easy to find and I didn't even know how to deal with them anyway, and so I decided to make this circuit out of TTL chips (74xx series). To make it easier (and also to raise its geek factor quite a bit :-) ) I decided that the clock should not show the actual time and the time the alarm is set to, but to show the remaining time to the alarm event. Since I needed the alarm for the same time every day (for school), I quickly learnt to convert it to actual time.
The fully assembled unit - missing some decorative items after having been kicked around for the last 20 years...

Monday, October 1, 2012

TV Auto-off from the '80s


In the eighties most TV sets did not have the sleep function that is standard on today's TVs. My grandfather was known to fall asleep about 5 minutes into watching any program on TV in the evening. Then, the TV would go on all night long. Those TVs in the eighties consumed a lot of power, so one day I decided to make a small device that would automatically switch off the TV when he falls asleep. Also, this device had to be very simple to operate so that grandpa wouldn't have to attend a course just to switch his TV on and off...