Nobody has the spec's of current consumption for the greeting card. You can easily measure it then look at battery lifetimes on the website of a battery manufacturer like Energizer.
You can see the supply current on the datasheet of a 555 or of a Cmos 555 or of a CD4060 IC. Did I mention a CD4541 timer IC?
You can see the supply current on the datasheet of a 555 or of a Cmos 555 or of a CD4060 IC. Did I mention a CD4541 timer IC?
