Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and AnswersTopic Posted by: Reliability & Maintainability Forum (firstname.lastname@example.org )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Original Message:Posted by: Sathees kumar Ramamoorthy (email@example.com )
Date posted: Thu Apr 3 9:28:42 US/Eastern 2003
Subject: Reg - MIL HDBK 217FN2
Dear Sir, I would like to be get clarified about three issues that I have faced in MIL HDBK 217FN2.
1. For computing Voltage stress factor(Pi S) (page 6.7) for Transistors, Applied Vce and Rated Vceo are required. Whether this Applied Vce has to be calculated when the Transistor is conducting or when it is in Cut-off state.
2. For computing Electrical stress factor(Pi S) (page 6.3) for Diodes(Low Frequency) Voltage stress ratio is required. It is mentioned in MIL HDBK 217FN2 that "Voltage is diode reverse voltage". I would like to get it confirmed that Voltage Applied and Voltage Rated both refer to Reverse voltage.
3. Power Dissipation is required for computing Power factor(Pi P) (page 9.2) for Resistors. Does this Power dissipation refer to Rated or Actual Power dissipation.