M
Michael
- Jan 1, 1970
- 0
I have a weakness for self-setting clocks. Designed and built two - both of
them WWV - back in the 90's when the cheapest pre-built commercial unit I found
cost about US$100. Today one can find pre-built "atomic" clocks for under
US$20. I saw one such clock at WalMart this summer and grabbed it. It's a
Sharp SPC315. Sets itself just fine here in New York State, which is a good
thing because its oscillator isn't accurate. Looks more like a desk clock than
an alarm clock, but it does have two independant alarms. The LCD display shows
Hr & Min with 1" high characters, day-of-week, month number and day of month
number, phase of moon, indoor and outdoor temperatures (not very accurate), and
alarm time.
As is usual with most things I buy I disassembled it for a look under the hood.
Surprise! Every other "atomic" alarm clock I've seen has its receiver
hard-built-in, either attached to the ferrite stick of the antenna or most
components mounted on the main board. This Sharp has an easily separable
receiver, a small glass PCB with wire antenna that is attached to the main board
via a 4-pin, 0.1" header. Soldered to the header though, not plugged, but can
be easily removed with a solder-sucker.
Want to design your own WWVB "atomic" clock?... maybe with 3" high LED digits?
Get the $20 Sharp clock and cannibalize it for the receiver.
DO NOT get the smaller and cheaper Sharp SPC364 clock. It's receiver is
different, integrated with the main board, and is not so easily removable.
them WWV - back in the 90's when the cheapest pre-built commercial unit I found
cost about US$100. Today one can find pre-built "atomic" clocks for under
US$20. I saw one such clock at WalMart this summer and grabbed it. It's a
Sharp SPC315. Sets itself just fine here in New York State, which is a good
thing because its oscillator isn't accurate. Looks more like a desk clock than
an alarm clock, but it does have two independant alarms. The LCD display shows
Hr & Min with 1" high characters, day-of-week, month number and day of month
number, phase of moon, indoor and outdoor temperatures (not very accurate), and
alarm time.
As is usual with most things I buy I disassembled it for a look under the hood.
Surprise! Every other "atomic" alarm clock I've seen has its receiver
hard-built-in, either attached to the ferrite stick of the antenna or most
components mounted on the main board. This Sharp has an easily separable
receiver, a small glass PCB with wire antenna that is attached to the main board
via a 4-pin, 0.1" header. Soldered to the header though, not plugged, but can
be easily removed with a solder-sucker.
Want to design your own WWVB "atomic" clock?... maybe with 3" high LED digits?
Get the $20 Sharp clock and cannibalize it for the receiver.
DO NOT get the smaller and cheaper Sharp SPC364 clock. It's receiver is
different, integrated with the main board, and is not so easily removable.
