Business Segments (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Business Segments [Abstract]
Number of business segments			2
Business segment information [Abstract]
Net sales	$ 7,864,000	$ 7,850,000	$ 21,535,000	$ 22,946,000
(Loss) income before income tax provision [Abstract]
General corporate expenses not allocated	(245,000)	(308,000)	(960,000)	(854,000)
Interest expense	(31,000)	(45,000)	(101,000)	(151,000)
Investment and other income, net	5,000	28,000	102,000	133,000
(Loss) income before income tax provision	778,000	725,000	(340,000)	2,212,000
Electronics Segment [Member]
Business segment information [Abstract]
Net sales	5,112,000	4,876,000	12,509,000	14,081,000
(Loss) income before income tax provision [Abstract]
(Loss) income before income tax provision	647,000	419,000	(1,143,000)	1,076,000
Power Units Segment [Member]
Business segment information [Abstract]
Net sales	2,762,000	2,974,000	9,036,000	9,256,000
(Loss) income before income tax provision [Abstract]
(Loss) income before income tax provision	402,000	620,000	1,762,000	2,011,000
Intersegment [Member]
Business segment information [Abstract]
Net sales	(10,000)	0	(10,000)	(391,000)
(Loss) income before income tax provision [Abstract]
(Loss) income before income tax provision	0	11,000	0	(3,000)
Domestic [Member] | Electronics Segment [Member]
Business segment information [Abstract]
Net sales	4,655,000	4,544,000	11,090,000	13,342,000
Domestic [Member] | Power Units Segment [Member]
Business segment information [Abstract]
Net sales	2,519,000	2,763,000	8,159,000	8,346,000
Foreign [Member] | Electronics Segment [Member]
Business segment information [Abstract]
Net sales	457,000	332,000	1,419,000	739,000
Foreign [Member] | Power Units Segment [Member]
Business segment information [Abstract]
Net sales	$ 243,000	$ 211,000	$ 877,000	$ 910,000