Estimation of constant failure rates of electronic components at reduced voltage stresses

1987 ◽  
Vol 18 (1) ◽  
pp. 1-8
Author(s):  
G.N. Sharma
Author(s):  
Yizhak Bot ◽  
Yoram Herrer ◽  
Haim Korenfeld ◽  
Yeuda Gabay

2010 ◽  
Vol 09 (04) ◽  
pp. 507-523 ◽  
Author(s):  
BEZALEL GAVISH ◽  
MARION SOBOL

A stochastic model is developed which can be used to set warranty periods so that a small percentage of items sold in a store are returned for rebates, repairs or replacements. If return to the store provides benefits to the retailer such as purchase of upgrades, ability to sell additional related goods or to sell snacks and other unrelated merchandise, while the customer is waiting, then profits may be maximized by setting warranty periods so that a larger percentage of the population will revisit the store. Results for products with initially high failure rates (TV sets, complex electronic components and cellular phones) versus products with gradually increasing failure rates (tires, batteries) are compared using simulations. Initially high rates of failure in conjunction with revenues from additional purchases that are greater than zero and initial losses that are low may be more lucrative than revenues from gradually increasing wear out replacements. Minimal levels of additional purchases, initial loss in value and rate reduction per number of periods can be established based on realistic simulation data in order for retailers and manufacturers to facilitate profit maximization using warranty policy.


Notification device like smoke detectors are critical and important part of a Fire Alarm Control Panel (FACP). Popularly used smoke alarms in commercial establishments in India are photoelectric smoke alarms (PESD) and ionization smoke alarms (ISD). In this study reliability assessments of PESD with Integrated Circuit (IC) – MC145010 and ISD with IC – MC145017 have been carried out on the basis of reliabilities of their respective electronic components. The cases considered are: (I) Failure rates of all components are equal and constant over time (II) Failure rates of all components are equal and follow Weibull distribution and (III) Failure rates of all components are different. To determine failure rates of 9 volt battery of both detectors additional assumptions taken are, (a) battery life is 10 years with constant failure rate, (b) battery life follows Weibull distribution. In this paper the reliability and failure rate of two types of smoke alarms have been calculated based on failure rates of their electronic parts like resistors, capacitors, Integrated Circuits etc. These failure rates have been subsequently used for reliability assessment of a non-addressable FACP containing four PESDs and four ISDs as notification device. A comparison of failure rates was also performed on the basis of two quality factors of electronic components – military specific and lower than military specific. Mean Time To Failure (MTTF) of PESD and ISD have been calculated in all the cases. Subsequently, MTTF values obtained in case III were used to approximate failure rates for case I case II.


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