Business Segments (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Business Segments [Abstract]
Number of business segments			2
Business segment information [Abstract]
Net sales	$ 7,509,000	$ 8,284,000	$ 13,671,000	$ 15,096,000
(Loss) income before income tax provision [Abstract]
General corporate expenses not allocated	(398,000)	(266,000)	(715,000)	(546,000)
Interest expense	(36,000)	(53,000)	(70,000)	(106,000)
Investment and other income, net	4,000	71,000	97,000	105,000
(Loss) income before income tax provision	227,000	947,000	(1,118,000)	1,487,000
Electronics Segment [Member]
Business segment information [Abstract]
Net sales	4,291,000	4,769,000	7,397,000	9,205,000
(Loss) income before income tax provision [Abstract]
(Loss) income before income tax provision	(57,000)	199,000	(1,790,000)	657,000
Power Units Segment [Member]
Business segment information [Abstract]
Net sales	3,218,000	3,619,000	6,274,000	6,282,000
(Loss) income before income tax provision [Abstract]
(Loss) income before income tax provision	714,000	972,000	1,360,000	1,391,000
Intersegment [Member]
Business segment information [Abstract]
Net sales	0	(104,000)	0	(391,000)
(Loss) income before income tax provision [Abstract]
(Loss) income before income tax provision	0	24,000	0	(14,000)
Domestic [Member] | Electronics Segment [Member]
Business segment information [Abstract]
Net sales	3,795,000	4,555,000	6,435,000	8,798,000
Domestic [Member] | Power Units Segment [Member]
Business segment information [Abstract]
Net sales	2,935,000	3,101,000	5,640,000	5,583,000
Foreign [Member] | Electronics Segment [Member]
Business segment information [Abstract]
Net sales	496,000	214,000	962,000	407,000
Foreign [Member] | Power Units Segment [Member]
Business segment information [Abstract]
Net sales	$ 283,000	$ 518,000	$ 634,000	$ 699,000