Note 6 - Inventories, net (Tables)

3 Months Ended

Jun. 30, 2019

Inventory Disclosure [Abstract]

Schedule of Inventory, Current [Table Text Block]

Inventories consist of:

	June 30, 2019			March 31, 2019
Purchased parts	$	2,527,004		$	2,709,235
Work-in-process		1,071,626			721,397
Finished goods		7,344			-
Less: Inventory reserve		(508,000	)		(498,000	)
	$	3,097,974		$	2,932,632