Export Sales and Major Customers (Details) - USD ($)	3 Months Ended		6 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2016	Aug. 31, 2015
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	$ 1,875,000	$ 2,212,000	$ 3,688,000	$ 4,595,000
Power Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	324,000	246,000	552,000	719,000
Hybrids [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	1,303,000	1,176,000	2,583,000	2,325,000
Field Effect Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	49,000	247,000	179,000	346,000
Power MOSFETS [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	199,000	543,000	374,000	1,205,000
Europe and Australia [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	16,000	3,000	16,000	9,000
Europe and Australia [Member] | Power Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	11,000	0	11,000	0
Europe and Australia [Member] | Hybrids [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	0	0	0
Europe and Australia [Member] | Field Effect Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	5,000	3,000	5,000	9,000
Europe and Australia [Member] | Power MOSFETS [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	0	0	0
Canada and Latin America [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	9,000	24,000	9,000	33,000
Canada and Latin America [Member] | Power Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	9,000	0	9,000	9,000
Canada and Latin America [Member] | Hybrids [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	0	0	0
Canada and Latin America [Member] | Field Effect Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	24,000	0	24,000
Canada and Latin America [Member] | Power MOSFETS [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	0	0	0
Far East and Middle East [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	83,000	79,000	171,000	179,000
Far East and Middle East [Member] | Power Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	83,000	4,000	83,000	4,000
Far East and Middle East [Member] | Hybrids [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	0	0	0
Far East and Middle East [Member] | Field Effect Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	15,000	5,000	29,000
Far East and Middle East [Member] | Power MOSFETS [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	0	60,000	83,000	146,000
United States [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	1,767,000	2,106,000	3,492,000	4,374,000
United States [Member] | Power Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	221,000	242,000	449,000	706,000
United States [Member] | Hybrids [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	1,303,000	1,176,000	2,583,000	2,325,000
United States [Member] | Field Effect Transistors [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	44,000	205,000	169,000	284,000
United States [Member] | Power MOSFETS [Member]
Revenues from domestic and export sales to unaffiliated customers
Revenues, Total	$ 199,000	$ 483,000	$ 291,000	$ 1,059,000