And now!
[... fanfare of trumpets ... ]
The Tystie Get-U-Up single-handers' watchkeeping alarm
Top left is a push on, push off power switch.
Top centre is a low intensity 12v green LED to show that the unit is functioning and to act as an indicator to set the time on the dial.
Centre is the runback timer, counting down, at about 4 minutes to go.
Bottom left is a jumbo high intensity LED. This is intended for 2.4V operation, so needs a 680 ohm resistor in series with it.
Right is a 90 dB pulsing piezo buzzer.
Centre, the timer has run back to zero and the buzzer is sounding, the red LED is on, and the green LED is off.
The whole thing is mounted above the centre window in the coachroof, near enough to the settees for me to hear, and requiring me to get up to a position where I can see out of the windows for a quick look around before I can switch it off or set it for a new time Unlike a kitchen timer, it will keep sounding until I switch it off. So often, I've woken up to find the kitchen timer has reached zero, and I'm not sure whether I slept through it or forgot to set it.
[ Slieve, thanks for the tip about the timer, too late for me, but maybe some other single-hander will benefit]