Note 6 - Inventories, net (Tables)

9 Months Ended

Dec. 31, 2018

Inventory Disclosure [Abstract]

Schedule of Inventory, Current [Table Text Block]

Inventories consist of:

	December 31, 2018			March 31, 2018
Purchased parts	$	2,799,562		$	3,571,874
Work-in-process		769,714			1,051,725
Finished goods		-			66,335
Less: Inventory reserve		(475,000	)		(420,000	)
	$	3,094,276		$	4,269,934