The article discuses a in sequence moving onto 25 LED timer circuit which might be started on the 1st day of December in order that each LeD brightens on each day until the 25th of December (on Christmas) when all the 25 LeD can be watched illuminated.
IC1-----IC2 = 4017
T1, T2 = BC547
pin15 capacitor, resistor are 0.22uF and 1M respectively
rest of the resistors are all 4k7
The Design
The offered digital Christmas candle light timer circuit is generally applied by configuring the above two circuits by making use of the following recommendations:
The left diagram above means the 25 LED timer circuit that may be required to light up in sequence from day#1 when the circuit is activated, until the 25he of December when the final 25th LeD lights up, at the rate of 1 LED per day.
The level is established by wiring or cascading three IC 4017 ICs. The clock inputs of all the three ICs are rigged with the clock output of the right hand side circuit making use of IC 4060, whose pin3 output is intended to be linked with the pin14 of all the IC 4017.
R1, R2 and C1 of IC1 are measured such that pin3 delivers a high clock after a period of specifically 24 hours, the moment the technique is activated.
This 24 hour clock pulse is given to the pin14 of the three 4017 ICs in order that a high logic shifts in sequence from pin3 of IC1 every single day until the 25th day when the last LED at pin#1 of IC3 lights up.
The circuit is operated choosing two 9V rechargeable batteries, one being attached perfectly with the supply pins of the IC steps even though the other attached by way of a 1K resistor.
The battery that is certainly plugged in by way of a 1K resistor is effectively linked with the circuit and confirms that the ICs are usually driven with the minimum essential current, in an effort to preserve the memory of the ICs in case that the main battery obtains exhausted in the midst of the 25 day period and while the user takes away it for recharging and replacing it back.
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