Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Condensed Consolidated Statements of Operations [Abstract]
Net sales	$ 14,413	$ 18,248
Cost of sales	8,902	10,864
Gross profit	5,511	7,384
Selling, general, and administrative expenses	3,272	3,904
Engineering expense	3,469	2,285
Operating income (loss)	(1,230)	1,195
Interest expense	173	134
Other expense - net	25	30
Income (loss) before income taxes	(1,428)	1,031
Income tax provision (benefit)	(600)	433
Net income (loss)	$ (828)	$ 598
Earnings (loss) per common share:
Basic net income (loss) per share	$ (0.09)	$ 0.06
Diluted net income (loss) per share	$ (0.09)	$ 0.06
Weighted-average basic shares outstanding	9,493,000	9,445,000
Weighted-average diluted shares outstanding	9,493,000	9,564,000