Engineering topics
Publications and source records attributed to Jones, N. D..
Fast-acting current limiting device provides current overload protection for vulnerable circuit elements and then re-establishes conduction path within milliseconds. Fuse can also perform as fast-acting switch to clear transient circuit overloads. Fuse takes advantage of large increase in electrical resistivity that occurs when liquid metal vaporizes.
The mercury-filled self-healing fuses developed for this program afford very good protection from circuit faults with rapid reclosure. Fuse performance and design parameters have been characterized. Life tests indicate a capability of 500 fuse operations. Fuse ratings are 150 v at 5, 15, 25 and 50 circuit A. A series of sample fuses using alumina and beryllia insulation have been furnished to NASA for circuit evaluation.
Thallium and xenon filled thyratron was developed that operates at tube envelope temperatures up to 750 C. This tube performs at peak voltage ratings of 2000 V forward and reverse and at an average current rating of 15 A for up to 11,000 hours.
The self-healing fuse is a very fast acting current overload protective device which opens and recloses in a few milliseconds. The fuse confines a mercury column in an insulated channel and returns the mercury to the channel after firing. Ratings 5 to 50 A at 600 peak volts are possible with a life of hundreds of cycles. Compared to conventional fuses, much less fault current energy fires the fuse by heating the mercury to boiling temperature. Next an arc discharge develops while explosive forces expel the liquid mercury from the channel. Then the high impedance arc either extinguishes immediately, or operates for a few milliseconds, until a switch opens the circuit.
Long-term performance tests of neon gas filled, high-temperature ceramic voltage-regulator tubes
Development and endurance testing of high temperature ceramic rectifiers and thyratrons
Mercury-filled self-healing fuses for protecting solid state circuits from faults - design and development
Mouse cage system provides versatility and ease in handling laboratory mice, cleaning their cages, and collecting uncontaminated metabolic test specimens. The cage, compact and free standing, contains a screened bottom and funnel channel to collect waste. The feed is in the cage top and thereby separates the food and waste.
High temperature and power gas diodes and thyratrons for nuclear electrical space power systems
High temperature high power gas diodes and thyratrons for large nuclear electrical space power systems, noting parameters of design and performance
Development of high temperature gas filled ceramic rectifiers, thyratrons, and voltage-regulator tubes