SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Zener diodes manufactured by Motorola and Siemens were tested. Apparent failure mode in all three groups was B (sub) V (Zener-breakdown-voltage) minimum failure. Both manufacturers had apporximately same amount of failure in each testing.
Zener diode function generator eliminates need for external reference voltage source
Tested Zeners were manufactured by Siemens and Motorola. Devices tested in groups 1 and 2 did quite well. Notable damage to both manufacturer lots occurred in group 2 testing.
High-current zener diode is connected in series with the positive input terminal of a dc supply to block the flow of direct current until a high-frequency control signal is applied across the zener diode. This circuit controls the switching of large dc signals.
Zener diode in parallel with a silicon transistor supplies the starting current for a transistor-regulated power supply.
Reliability data and test arrangements for zener diodes used in Saturn program
Function generator utilizing parallel impedance networks with zener diodes produces functions which are discontinuous in slope. The function generated appears at the output of the parallel network in the form of a voltage varying in time.
Linear sawtooth voltage wave generator with transistor timing circuit having capacitor and zener diode feedback loops
Nondestructive test methods for Saturn program Zener diodes evaluated to develop screening procedures for potential failures
For obtaining optimum performance from cooled infrared detectors used in astronomy, it is often necessary to operate the preamplifier transistor (usually a JFET) at a higher temperature than that provided by the cryogen. Various means of elevating the temperature of the FET above the temperature of its environment are considered. A description is presented of a method which uses a 10 V Zener diode (actually an avalanche diode) as a self-stabilizing heater element. The diode is mounted in good thermal contact with the FET, and both are isolated from the work surface by a link of poor conductivity. The diode is driven by a stable, constant voltage power supply.
Report evaluates effects of power and temperature overstress on Motorola and Siemens devices. Reverse bias leakage maximum limit failure and Zener-breakdown maximum limit failure were common. Other failures are described.
Tested diodes were manufactured aby Motorola and Siemens. Both sample lots performed well in groups 1 and 3 testing. Group 2 testing was most detrimental of three groups. Extreme heat was big factor in failure mode.
Siemens and Motorola diodes were tested. Of three stress groups, group 2 prove to be most detrimental to both sample lots.
Report evaluates effects of power and temperature overstress on General Semi-conductor and Siemens devices. Excessive failure rates limited testing. Failure modes are described.
Report evaluates effects of power and temperature overstress on General Semiconductor and Siemens devices. Mechanical disruption is prominent failure mode. Other failures are described.
Report describes effects of power and temperature overstress on Motorola and Siemens diodes. Failure was predominantly due to melted metal on die connections. Other failures are described.
A conditioning circuit is provided with a constant current diode in series with a zener diode, the former having a high dynamic impedance and the latter a low dynamic impedance. The constant current diode can receive an input voltage with PARD. In conjunction with the zener diode fixed to a ground, a voltage divider is provided which can give an output voltage whose PARD was significantly reduced. The conditioning circuit is effective down to dc.
A computer program which simulates the operation of the Viking Orbiter Power Subsystem has been developed. The program simulates the characteristics and interactions of a solar array, battery, battery charge controls, zener diodes, power conditioning equipment, and the battery spacecraft and zener diode-spacecraft thermal interfaces. This program has been used to examine the operation of the Orbiter power subsystem during critical phases of the Viking mission - from launch, through midcourse maneuvers, Mars orbital insertion, orbital trims, Lander separation, solar occultations and unattended operation - until the end of the mission. A typical computer run for the first 24 hours after launch is presented which shows the variations in solar array, zener diode, battery charger, batteries and user load characteristics during this period.