Supplemental Balance Sheet Information (Details) - USD ($)	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Inventories
Work in progress	$ 388,252	$ 468,839
Component parts	6,775,870	7,271,908
Finished goods	2,285,836	2,368,855
Reserve for obsolete and excess inventory	(1,619,417)	(1,597,648)
Inventory, Net	7,830,541	8,511,954
Property, plant and equipment
Total property, plant and equipment at cost	32,048,546	32,048,546
Less accumulated depreciation and amortization	(27,225,397)	(26,314,505)
Total Property, Plant and Equipment, Net	4,823,149	5,734,041
Other accrued liabilities
Accrued compensation expense	1,060,777	1,132,534
Customer deposits	370,885	612,908
Other	419,021	264,524
Other Accrued Liabilities	$ 1,850,683	2,009,966
Maximum [Member]
Property, plant and equipment
Estimated Useful Life	35 years
Minimum [Member]
Property, plant and equipment
Estimated Useful Life	3 years
Machinery and equipment [Member]
Property, plant and equipment
Total property, plant and equipment at cost	$ 18,073,352	18,073,352
Machinery and equipment [Member] | Maximum [Member]
Property, plant and equipment
Estimated Useful Life	10 years
Machinery and equipment [Member] | Minimum [Member]
Property, plant and equipment
Estimated Useful Life	3 years
Buildings [Member]
Property, plant and equipment
Total property, plant and equipment at cost	$ 13,055,628	13,055,628
Buildings [Member] | Maximum [Member]
Property, plant and equipment
Estimated Useful Life	35 years
Buildings [Member] | Minimum [Member]
Property, plant and equipment
Estimated Useful Life	28 years
Land and Land improvements [Member]
Property, plant and equipment
Total property, plant and equipment at cost	$ 919,566	$ 919,566
Land and Land improvements [Member] | Maximum [Member]
Property, plant and equipment
Estimated Useful Life	7 years
Land and Land improvements [Member] | Minimum [Member]
Property, plant and equipment
Estimated Useful Life	5 years