Accrued Expenses: (Details) - USD ($)	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Accrued expenses:
Warranty	$ 878,901	$ 777,599	$ 701,456
Salary, benefits and payroll taxes	537,451	787,277
Professional fees	353,012	431,612
Income taxes payable		185,151
Other	799,167	1,895,651
Total	2,568,531	4,077,290
EDC program costs	$ 600,000	$ 1,500,000