Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net loss	$ (698,004)	$ (583,137)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	323,405	306,032
Gain on disposal of equipment	(36,886)	0
Deferred income taxes	(176,830)	(43,000)
Changes in operating assets and liabilities
Accounts receivable	(1,187,835)	(1,197,937)
Contract assets	118,301	0
Inventories	580,978	(877,722)
Other current assets	(78,333)	(160,452)
Accounts payable	599,625	924,168
Accrued wages and salaries	119,473	212,746
Other accrued expenses	183,149	(212,227)
Unearned revenue and customer deposits	(145,802)	(19,881)
Net cash used in operating activities	(398,759)	(1,651,410)
Cash flows from investing activities
Capital expenditures	(93,085)	(413,419)
Proceeds from the sale of equipment	96,350	0
Proceeds from short-term investments	1,133,641	498,000
Purchases of short-term investments	(737,477)	0
Net cash provided by investing activities	399,429	84,581
Cash flows from financing activities
Cash dividends paid	(96,613)	(212,549)
Net cash used in financing activities	(96,613)	(212,549)
Net decrease in cash and cash equivalents	(95,943)	(1,779,378)
Cash and cash equivalents at beginning of period	1,387,075	4,045,101
Cash and cash equivalents at end of period	$ 1,291,132	$ 2,265,723