Condensed Consolidated Statements of Cash Flows - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net (loss) income	$ (1,701,000)	$ 194,000
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Inventory allowance	700,000	194,000
Deferred tax expense	184,000	73,000
Depreciation and amortization	1,394,000	1,344,000
Share-based compensation expense -stock options	253,000	129,000
Share-based compensation expense-restricted stock units	306,000	142,000
Unrealized loss on investment in securities	219,000	620,000
(Gain) on sale of equipment	(40,000)	0
Changes in operating assets and liabilities:
Trade accounts receivable	(1,763,000)	(2,502,000)
Inventories	(7,133,000)	3,932,000
Prepaid expenses and other current assets	244,000	(145,000)
Other assets	14,000	84,000
ROU Assets and Lease Liabilities	(23,000)	250,000
Accounts payable	764,000	(191,000)
Accrued compensation and related taxes	(536,000)	364,000
Accrued warranty expense	(258,000)	(457,000)
Deferred revenue	443,000	585,000
Accrued other expenses and other current liabilities	631,000	(172,000)
Net cash (used in) provided by operating activities	(6,302,000)	4,444,000
Investing activities
Proceeds from the sale of property, plant, and equipment	72	0
Purchases of property, plant and equipment	2,416,000	946,000
Net cash used in investing activities	(2,344,000)	(946,000)
Financing activities
Dividends paid	1,172,000	1,002,000
Repurchase of common stock	0	269,000
Proceeds from issuance of common stock, net of costs	11,559,000	0
Proceeds from credit facility and notes payable	5,743,000	2,196,000
Repayment of credit facility and notes payable	(3,730,000)	(2,273,000)
Net cash provided by (used in) financing activities	12,400,000	(1,348,000)
Net change in cash and cash equivalents	3,754,000	2,150,000
Cash and cash equivalents, beginning of year	6,826,000	4,676,000
Cash and cash equivalents, end of year	10,580,000	6,826,000
Supplemental disclosure
Interest paid	$ 53,000	$ 22,000
Non-cash financing activity
Common Stock issued under restricted stock units	298	128