National Electronics NL-1031 Ignitor Tube Size B

The National Electronics NL-1031 Size B ignitor tube is an ignitor-triggered vacuum device used to start mercury pool rectifiers in high-current circuits. Within National Electronics’ line of ignitrons, the “Size B” designation refers to its envelope size, helping identify compatible sockets and assemblies. The NL‑1031 functions as the control element that fires the main rectifier in ignitor-fired mercury pool rectifier systems, delivering high peak current capacity when triggered. This model appears in historical National Electronics documentation and current supplier catalogs under the NL‑1031 name, illustrating its continued relevance in vintage power-electronics equipment. Typical applications include power supplies and other high-voltage, high-current rectifier configurations where rapid triggering of the main rectifier is required.