External reset system prediction time of LAPAN satellite using IC 4536 programmable timer circuit

Abstract

For ensuring missions continuity in every satellite, all satellite systems are required to be active non-stop. But, for important maintenance reason, satellite system also needs reset condition when all satellite systems, except TTC unit, can be refreshed for a while every determined time. IC 4536 programmable timer circuit has main function to count every about 14 days then give signal reset for about 200 milliseconds. High level output voltage duration time can be adjusted by determining the values of capacitor and decode out, while low level output voltage duration time can be adjusted by determining resistor value. External reset system prediction time calculation shows that using capacitor C2 value 300 nF and decode out value 24 can achieve 14 day 18 hour 39 minute 31 second 172 millisecond high level output voltage duration time. Observation result shows that using resistor R3 value 2 kΩ can give 230 millisecond reset signal time. High level output voltage duration time target test shows that using capacitor C2 value 300 nF and decode out value 20 can give counting time up to 21 hours 41 minutes 59 seconds 792 milliseconds.