How to run an electro mechanical quartz clock on a 3 cell damp salt battery ?
I have seen various LCD clocks and calculators but not the humble 1.5 Volts quartz clock being run from a home made battery.
I tried the lemon battery cell as well, but it required about 6 lemons and the clock stopped running after about 20 seconds.
For the salt battery I only need 3 cells.
How does it work ?
The trick here is to connect a capacitor in parrallel with the battery and clock to make it work.
It appears that the clock needs a buffered supply. When the second hand moves the stepper motor in the clock creates a small power surge which the capacitor provides.
These home made batteries have only small current carrying capacity of about 1 milli Ampère. The clock motor briefly needs more, even the multimeter doesn't show it and shows a 0.4 mA value.
Materials needed:
Three old 35 mm film containers
Kitchen salt
Three strands of 2.5 mm² wire
Three galvanised woodscrews
A bit of small gauge wire to connect the cells, or use some alligator clips and leads
A quartz clock with no battery
At the moment I am doing a duration test and will keep you posted with the results.
Start 28 June 2009 at about 20:30 hrs.
UPDATE ! 01 July 09 well the cklock ran for 12 hours and stopped at 0900 hrs the next morning.
The galv. screw had corroded and by wiggleing it a bit the clock started again. and stopped a few minutes later.
Findings: as experiment to prove it works fine.
For accurate time keeping, just get a normal one dollar 1.5 Volts battery, which will at least last 1 year.
I have seen various LCD clocks and calculators but not the humble 1.5 Volts quartz clock being run from a home made battery.
I tried the lemon battery cell as well, but it required about 6 lemons and the clock stopped running after about 20 seconds.
For the salt battery I only need 3 cells.
How does it work ?
The trick here is to connect a capacitor in parrallel with the battery and clock to make it work.
It appears that the clock needs a buffered supply. When the second hand moves the stepper motor in the clock creates a small power surge which the capacitor provides.
These home made batteries have only small current carrying capacity of about 1 milli Ampère. The clock motor briefly needs more, even the multimeter doesn't show it and shows a 0.4 mA value.
Materials needed:
Three old 35 mm film containers
Kitchen salt
Three strands of 2.5 mm² wire
Three galvanised woodscrews
A bit of small gauge wire to connect the cells, or use some alligator clips and leads
A quartz clock with no battery
At the moment I am doing a duration test and will keep you posted with the results.
Start 28 June 2009 at about 20:30 hrs.
UPDATE ! 01 July 09 well the cklock ran for 12 hours and stopped at 0900 hrs the next morning.
The galv. screw had corroded and by wiggleing it a bit the clock started again. and stopped a few minutes later.
Findings: as experiment to prove it works fine.
For accurate time keeping, just get a normal one dollar 1.5 Volts battery, which will at least last 1 year.
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Learning