XML 76 R43.htm IDEA: XBRL DOCUMENT v3.22.1
Note 7 - Agreements and Commitments - Changes in Warranty Obligations (Details) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2022
Dec. 31, 2021
Balance $ 962,313 $ 1,056,613
Warranty costs charged to cost of goods sold 0 177,302
Utilization charges against reserve 0 (191,068)
Release of accrual related to expired warranties 0 0
Foreign currency effect (19,964) (80,534)
Balance $ 942,349 $ 962,313