NET SALES BY PRODUCT LINE AND GEOGRAPHY (Details) - USD ($)	12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Revenue from External Customer
Net sales	$ 18,396,000	$ 16,302,000
Magnetic components
Revenue from External Customer
Net sales	9,251,000	7,924,000
Potted coil assembly
Revenue from External Customer
Net sales	5,962,000	5,268,000
Electro-mechanical assemblies
Revenue from External Customer
Net sales	3,060,000	3,098,000
Large transformers
Revenue from External Customer
Net sales	123,000	12,000
Total Torotel products
Revenue from External Customer
Net sales	$ 18,396,000	$ 16,302,000