Note 6 - Inventories, net (Tables)

3 Months Ended

Jun. 30, 2018

Inventory Disclosure [Abstract]

Schedule of Inventory, Current [Table Text Block]

Inventories consist of:

	June 30, 2018			March 31, 2018
Purchased parts	$	3,386,296		$	3,571,874
Work-in-process		1,125,268			1,051,725
Finished goods		14,324			66,335
Less: Inventory reserve		(430,000	)		(420,000	)
	$	4,095,888		$	4,269,934