Last week ,we have been problem on the same problem in this week.We research and troubleshoot about this part in our project.We have to check the output from pin 3 and pin 10 to produce 2hz. From that,we will know our project will be function well. Below shown picture of our critical part in our circuit.
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| Difficul part |
Explanation of above picture:
Based on the pic above,for Ic 1 which is 4060,for every pin 1,2,3,7,5,4,6,14,13 and 15 their have their own symbol and have their own calculation.For our circuit,we need to produce 2hz with using pin 3 which is Q13 counter output 1638(timing diagram at negative edge clock).It means pin 3 is timer counting until 1638 (which is wave can see at datasheet) than output wil produce.Led will flashing late so we exchange the circuit into pin 7 which is Q3 count is 16,the led will flashing faster than the original circuit.
By the way for IC2 counter and IC3a 4 input And Gate are wired in order to divided by 3000 the 2hz clock,therefore a pulse every 30 minutes is available at the clock input of IC5.The division factor of IC is controlled by IC3B .
Below show the timing diagram:
Using the timing diagram ,we change the circuit to make a faster result .
For watch crytsal wil update next week
Note :
- wanting the utmost precision and if a digital frequency meter is available, a 50pF 50V Ceramic Trimmer Capacitor can be used in placeof C2.It must be adjusted in order to read exactly 32.768khz on the meter display with the input probe connected to pin9 of Ic1.
