Features
Simple to program and use
Timer for - 24hrs daily, weekday, weekend or 7 day setting
10 off & 10 on programs with 1 minute increments
Random setting
Daylight saving advance function
Override switch
Countdown function
Battery back-up
On/off LED indicator
Power 12VDC
5A rating (10A with thickened tracks)
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Here's how the timer module starts out in life - as the "works" in an Arlec PC697 digital timer. The module, which is a separate assembly at the top of the timer (as seen here) is easily removed from the "case". The rest of the device isn't used - but we're sure a use will turn up for it shortly!
With the price of imported electrical and electronics goods
these days, often it simply isn’t economic to build. But there are times when
those same imports can yield components which make other do-it-yourself projects
viable.
Such is the case with this project. It’s a 12V DC timer, based
around a clock module that’s found in some commercial 240V mains timers. The
module then becomes the heart of the timer enabling the user the flexibility to
program the unit with ease. Its output controls a relay which in turn can be
used to switch a low voltage such as 12 VDC.
The project consists of the timer module, removed from an Arlec
PC697 digital mains timer, which is then mounted in a Zippy box along with a
simple power supply and relay interface.
The SPDT relay contacts are rated at 10AC (120V) but we’d be
loathe to try to switch this sort of current and expect any sort of longevity. A
higher-rated relay should be substituted if heavy currents are to be switched.
The PC board tracks should also be thickened with solder and/or wire for higher
current.