NVE (NVEC) 10-K 5 May 21 2021 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Apr. 30, 2021	Sep. 30, 2020
Document Information [Line Items]
Entity Registrant Name	NVE CORP /NEW/
Entity Central Index Key	0000724910
Trading Symbol	nvec
Current Fiscal Year End Date	--03-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)		4,833,232
Entity Public Float			$ 147
Entity Shell Company	false
Document Type	10-K
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false
Title of 12(b) Security	Common stock, $0.01 par value

Balance Sheets

Balance Sheets - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Current assets
Cash and cash equivalents	$ 10,427,340	$ 8,065,594
Marketable securities, short-term	7,678,957	19,084,814
Accounts receivable, net of allowance for uncollectible accounts of $15,000	1,964,281	2,694,018
Inventories	3,900,777	3,884,450
Prepaid expenses and other assets	391,278	655,835
Total current assets	24,362,633	34,384,711
Fixed assets
Machinery and equipment	9,254,664	9,280,062
Leasehold improvements	1,810,872	1,797,245
Property, Plant and Equipment, Gross, Ending Balance	11,065,536	11,077,307
Less accumulated depreciation and amortization	10,728,853	10,494,840
Net fixed assets	336,683	582,467
Deferred tax assets	73,538	108,119
Marketable securities, long-term	47,038,669	43,606,495
Right-of-use asset – operating lease	689,216	816,358
Total assets	72,500,739	79,498,150
Current liabilities
Accounts payable	336,591	186,993
Accrued payroll and other	540,474	482,074
Operating lease	150,273	127,134
Total current liabilities	1,027,338	796,201
Operating lease	581,459	706,600
Total liabilities	1,608,797	1,502,801
Shareholders’ equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,833,232 issued and outstanding as of March 31, 2021 and 4,835,038 as of March 31, 2020	48,332	48,350
Additional paid-in capital	19,338,127	19,383,956
Accumulated other comprehensive income	1,101,119	516,523
Retained earnings	50,404,364	58,046,520
Total shareholders’ equity	70,891,942	77,995,349
Total liabilities and shareholders’ equity	$ 72,500,739	$ 79,498,150

Balance Sheets (Parentheticals)

Balance Sheets (Parentheticals) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Allowance for uncollectible accounts	$ 15,000	$ 15,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	6,000,000	6,000,000
Common stock, shares issued (in shares)	4,833,232	4,835,038
Common stock, shares outstanding (in shares)	4,833,232	4,835,038

Statements of Income

Statements of Income - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue
Revenue	$ 21,366,246	$ 25,412,163
Cost of sales	4,121,461	4,889,295
Gross profit	17,244,785	20,522,868
Expenses
Research and development	3,184,754	3,690,539
Selling, general, and administrative	1,316,427	1,317,543
Total expenses	4,501,181	5,008,082
Income from operations	12,743,604	15,514,786
Interest income	1,498,148	1,787,117
Income before taxes	14,241,752	17,301,903
Provision for income taxes	2,547,368	2,775,261
Net income	$ 11,694,384	$ 14,526,642
Net income per share – basic (in dollars per share)	$ 2.42	$ 3
Net income per share – diluted (in dollars per share)	2.42	3
Cash dividends declared per common share (in dollars per share)	$ 4	$ 4
Weighted average shares outstanding
Basic (in shares)	4,834,054	4,845,627
Diluted (in shares)	4,834,462	4,847,294
Product [Member]
Revenue
Revenue	$ 20,540,557	$ 24,400,192
Contract Research and Development [Member]
Revenue
Revenue	$ 825,689	$ 1,011,971

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net income	$ 11,694,384	$ 14,526,642
Unrealized gain from marketable securities, net of tax	584,596	599,248
Comprehensive income	$ 12,278,980	$ 15,125,890

Statements of Shareholders' Equ

Statements of Shareholders' Equity - USD ($)	Cumulative Effect, Period of Adoption, Adjustment [Member]Common Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Mar. 31, 2019		4,846,010
Balance at Mar. 31, 2019		$ 48,460	$ 19,910,558	$ (82,725)	$ 62,903,918	$ 82,780,211
Exercise of stock options (in shares)		2,000
Exercise of stock options		$ 20	112,340			112,360
Repurchase of common stock (in shares)		(12,972)
Repurchase of common stock		$ (130)	(687,302)			(687,432)
Unrealized gain on marketable securities, net of tax				599,248		599,248
Net income					14,526,642	14,526,642
Total comprehensive income						15,125,890
Stock-based compensation			48,360			48,360
Cash dividends declared ($4.00 per share of common stock)					(19,384,040)	(19,384,040)
Balance (in shares) at Mar. 31, 2020	4,835,038
Balance at Mar. 31, 2020		$ 48,350	19,383,956	516,523	58,046,520	77,995,349
Repurchase of common stock (in shares)		(1,806)
Repurchase of common stock		$ (18)	(91,401)			(91,419)
Unrealized gain on marketable securities, net of tax				584,596		584,596
Net income					11,694,384	11,694,384
Total comprehensive income						12,278,980
Stock-based compensation			45,572			45,572
Cash dividends declared ($4.00 per share of common stock)					(19,336,540)	(19,336,540)
Balance (in shares) at Mar. 31, 2021		4,833,232
Balance at Mar. 31, 2021		$ 48,332	$ 19,338,127	$ 1,101,119	$ 50,404,364	$ 70,891,942

Statements of Shareholders' E_2

Statements of Shareholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Common stock per share (in dollars per share)	$ 4	$ 4

Statements of Cash Flows

Statements of Cash Flows - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING ACTIVITIES
Net income	$ 11,694,384	$ 14,526,642
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	542,926	549,969
Stock-based compensation	45,572	48,360
Deferred income taxes	(129,155)	77,779
Changes in operating assets and liabilities:
Accounts receivable	729,737	301,620
Inventories	(16,327)	380,426
Prepaid expenses and other assets	391,699	(394,504)
Accounts payable and accrued expenses	105,996	405,481
Net cash provided by operating activities	13,364,832	15,895,773
INVESTING ACTIVITIES
Purchases of fixed assets	(62,727)	(52,041)
Purchases of marketable securities	(10,512,400)	(7,196,330)
Proceeds from maturities and sales of marketable securities	19,000,000	12,500,000
Net cash provided by investing activities	8,424,873	5,251,629
FINANCING ACTIVITIES
Proceeds from exercise of stock options		112,360
Repurchase of common stock	(91,419)	(687,432)
Payment of dividends to shareholders	(19,336,540)	(19,384,040)
Net cash used in financing activities	(19,427,959)	(19,959,112)
Increase in cash and cash equivalents	2,361,746	1,188,290
Cash and cash equivalents at beginning of year	8,065,594	6,877,304
Cash and cash equivalents at end of year	10,427,340	8,065,594
Supplemental disclosures of cash flow information:
Cash paid during the year for income taxes	$ 2,438,788	$ 2,586,661

Note 1 - Description of Busines

Note 1 - Description of Business	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Business Description and Basis of Presentation [Text Block]	NOTE 1. We develop and sell devices that use spintronics, a nanotechnology that relies on electron spin rather than electron charge to acquire, store, and transmit information. We operate in one

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Basis of Presentation and Significant Accounting Policies [Text Block]	NOTE 2. Cash and Cash Equivalents We consider all highly liquid investments with maturities of three Fair Value of Financial Instruments The carrying amount of cash and cash equivalents, accounts receivable, and accounts payable approximates fair value because of the short maturity of these instruments. Fair values of marketable securities are based on quoted market prices. Concentration of Risk and Financial Instruments Financial instruments potentially subject to significant concentrations of credit risk consist principally of cash equivalents, marketable securities, and accounts receivable. Cash and cash equivalents have been maintained in financial institutions we believe have high credit quality, however these accounts are generally in excess of federally insured amounts. We have invested our excess cash in corporate-backed and municipal-backed bonds and money market instruments. Our investment policy prescribes purchases of only high-grade securities, and limits the amount of credit exposure to any one 19 may one Our customers are throughout the world. We generally do not 19 Additionally, we are dependent on critical suppliers including our packaging vendors and suppliers of certain raw silicon and semiconductor wafers that are incorporated in our products. The effects of the COVID- 19 Accounts Receivable and Allowance for Doubtful Accounts We grant credit to customers in the normal course of business and at times may no 2021 2020. Inventories Inventories are stated at the lower of cost or net realizable value. Cost is determined by the first first Product Warranty In general we warranty our products to be free from defects in material and workmanship for one Fixed Assets Fixed assets are stated at cost. Depreciation of machinery and equipment is recorded over the estimated useful lives of the assets, generally five five not 2021 2020. $308,511 2021 364,409 2020. Revenue Recognition We recognize revenue when we satisfy performance obligations by the transfer of control of products or services to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those products or services. Revenue is disaggregated into product sales and contract research and development to depict the nature, amount, timing of revenue recognition and economic characteristics of our business, and is represented within the financial statements. We recognize revenue from product sales to customers and distributors when we satisfy our performance obligation, at a point in time, on product shipment or delivery to our customer or distributor as determined by agreed on shipping terms. Shipping charges billed to customers are included in product sales and the related shipping costs are included in cost of sales. Under certain limited circumstances, our distributors may third We recognize contract research and development revenue over a period of time as the performance obligation is satisfied over a period of time rather than a point in time. Contracts have specifications unique to each customer and do not Accounts receivable is recognized when we have transferred a good or service to a customer and our right to receive consideration is unconditional through the completion of our performance obligation. A contract asset is recognized when we have a right to consideration from the transfer of goods or services to a customer but have not not no March 31, 2021 March 31, 2020. Our performance obligations related to product sales and contract research and development contracts are satisfied in one one 606, Revenue from Contracts with Customers not not one Income Taxes We account for income taxes using the asset and liability method. Deferred income taxes are provided for temporary differences between the financial reporting and tax bases of assets and liabilities. We provide valuation allowances against deferred tax assets if we determine that it is less likely than not Research and Development Expense Recognition Research and development costs are expensed as they are incurred. Customer-sponsored research and development costs are included in cost of sales. Stock-Based Compensation We measure stock-based compensation cost at the grant date based on the fair value of the award and recognize the compensation expense over the requisite service period, which is generally the vesting period. We recognize any forfeitures as they occur. Net Income Per Share Net income per basic share is computed based on the weighted-average number of common shares issued and outstanding during each year. Net income per diluted share amounts assume exercise of all stock options. The following table shows the components of diluted shares: Year Ended March 31 2021 2020 Weighted average common shares outstanding – basic 4,834,054 4,845,627 Dilutive effect of stock options 408 1,667 Shares used in computing net income per share – diluted 4,834,462 4,847,294 Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Recently Issued Accounting Standards New Accounting Standards Not In December 2019, No. 2019 12, Income Taxes (Topic 740 Simplifying the Accounting for Income Taxes 2019 12 740 2019 12 December 15, 2020 2022 not In June 2016, No. 2016 13, Financial Instruments Credit Losses (Topic 326 2016 13 November 2018 No. 2018 19, Codification Improvements to Topic 326, Credit Losses November 2019, No. 2019 11, Codification Improvements to Topic 326, 2016 13. November 2019 No. 2019 10, Financial Instruments Credit Losses (Topic 326 815 842 February 2020 No. 2020 02, Financial Instruments Credit Losses (Topic 326 842 No. 119 No. 2016 02, 842 2016 13 three March 2020, No. 2020 03, Codification Improvements to Financial Instruments 2019 10 2020 02, 2016 13 December 15, 2022 2024 not

Note 3 - Fair Value of Financia

Note 3 - Fair Value of Financial Instruments	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Fair Value Disclosures [Text Block]	NOTE 3. Our corporate bonds and money market funds are classified as available-for-sale securities and carried at estimated fair value. Unrealized holding gains and losses are included in accumulated other comprehensive income in the statement of shareholders' equity. Corporate bonds with remaining maturities less than one one three The fair value of our available-for-sale securities as of March 31, 2021 Total <1 Year 1 3 Years 3 5 Years $ 64,860,822 $ 17,822,153 $ 36,716,130 $ 10,322,539 Total available-for-sale securities represented approximately 89% March 31, 2021 20 47 Generally accepted accounting principles establish a framework for measuring fair value, provide a definition of fair value, and prescribe required disclosures about fair-value measurements. Generally accepted accounting principles define fair value as the price that would be received to sell an asset or paid to transfer a liability. Fair value is a market-based measurement that should be determined using assumptions that market participants would use in pricing an asset or liability. Generally accepted accounting principles utilize a valuation hierarchy for disclosure of fair value measurements. The categorization within the valuation hierarchy is based on the lowest level of input that is significant to the fair value measurement. The categories within the valuation hierarchy are described as follows: Level 1 Level 2 2 Level 3 Money market funds are included on the balance sheets in “Cash and cash equivalents.” Corporate bonds are included on the balance sheets in “Marketable securities, short term” and “Marketable securities, long term.” The following table shows the estimated fair value of assets that were accounted for at fair value on a recurring basis: As of March 31, 2021 As of March 31, 2020 Level 1 Level 2 Total Level 1 Level 2 Total Money market funds $ 10,143,196 $ - $ 10,143,196 $ 7,903,433 $ - $ 7,903,433 Corporate bonds - 54,717,626 54,717,626 - 62,691,309 62,691,309 Total $ 10,143,196 $ 54,717,626 $ 64,860,822 $ 7,903,433 $ 62,691,309 $ 70,594,742 Our available-for-sale securities as of March 31, 2021 2020, As of March 31, 2021 As of March 31, 2020 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Estimated Fair Value Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Estimated Fair Value Money market funds $ 10,143,196 $ - $ - $ 10,143,196 $ 7,903,433 $ - $ - $ 7,903,433 Corporate bonds 53,308,105 1,570,195 (160,674 ) 54,717,626 62,030,120 752,621 (91,432 ) 62,691,309 Total $ 63,451,301 $ 1,570,195 $ (160,674 ) $ 64,860,822 $ 69,933,553 $ 752,621 $ (91,432 ) $ 70,594,742 The following table shows the gross unrealized holding losses and fair value of our available-for-sale securities with unrealized holding losses, aggregated by class of securities and length of time that individual securities had been in a continuous unrealized loss position as of March 31, 2021 2020. Less Than 12 Months 12 Months or Greater Total Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses As of March 31, 2021 Corporate bonds $ 10,322,539 $ (160,674 ) $ - $ - $ 10,322,539 $ (160,674 ) Total $ 10,322,539 $ (160,674 ) $ - $ - $ 10,322,539 $ (160,674 ) As of March 31, 2020 Corporate bonds $ 19,525,169 $ (91,432 ) $ - $ - $ 19,525,169 $ (91,432 ) Total $ 19,525,169 $ (91,432 ) $ - $ - $ 19,525,169 $ (91,432 ) We did not March 31, 2021. None not 19 not not not March 31, 2021.

Note 4 - Inventories

Note 4 - Inventories	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Inventory Disclosure [Text Block]	NOTE 4. Inventories are shown in the following table: March 31 2021 2020 Raw materials $ 660,678 $ 1,017,451 Work in process 2,220,723 1,863,000 Finished goods 1,019,376 1,003,999 Total inventories $ 3,900,777 $ 3,884,450

Note 5 - Stock-based Compensati

Note 5 - Stock-based Compensation	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	NOTE 5. Stock Option Plan Our 2000 may five one ten not not $45,572 2021 $48,360 2020. Valuation assumptions We use the Black-Scholes standard option-pricing model to determine the fair value of stock options. The following assumptions were used to estimate the fair value of options granted: Year Ended March 31 2021 2020 Risk-free interest rate 0.2 – 0.4% 1.7 % Expected volatility 34 – 35% 37 % Expected life (years) 4.6 4.6 Dividend yield 7.0 – 7.4% 5.9 % The determination of the fair value of the awards on the date of grant using the Black-Scholes model is affected by our stock price as well as assumptions of other variables, including projected stock option exercise behaviors, risk-free interest rate, and expected volatility of our stock price in future periods. Our estimates and assumptions affect the amounts reported in the financial statements and accompanying notes. Expected life We analyze historical exercise and termination data to estimate the expected life assumption. We believe historical data currently represents the best estimate of the expected life of a new option. Risk-free interest rate The risk-free rate is based on the yield of U.S. Treasury securities on the grant date for maturities similar to the expected lives of the options. Volatility We use historical volatility to estimate the expected volatility of our common stock. Dividend yield We assumed a 7.0% 7.4% 2021 5.9% 2020 Tax effects of stock-based compensation Stock-based compensation increased deferred tax assets by $9,971 2021 $10,581 2020. General stock option information The following table summarizes information on options outstanding as of March 31, 2021: Ranges of Exercise Prices Number Outstanding Weighted Average Exercise Price Weighted Remaining Contractual Life (years) $49.86 – $67.69 22,000 $ 59.85 5.3 $76.13 – $107.86 8,000 92.00 6.9 30,500 $ 68.28 5.7 A summary of our stock options is shown in the following table: Option Shares Reserved Options Outstanding Weighted Average Option Exercise Price At March 31, 2019 135,230 22,000 $ 70.89 Granted (4,000 ) 4,000 $ 67.65 Exercised - (2,000 ) $ 56.18 At March 31, 2020 131,230 24,000 $ 71.58 Granted (6,500 ) 6,500 $ 56.12 At March 31, 2021 124,730 30,500 $ 68.28 The remaining weighted-average exercisable life was 5.7 March 31, 2021 6.6 March 31, 2020. 28,000 March 31, 2021 24,000 March 31, 2020. March 31, 2021, $230,540, $191,140 $47,140 2021. $1,568 March 31, 2021 first 2022.

Note 6 - Income Taxes

Note 6 - Income Taxes	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Income Tax Disclosure [Text Block]	NOTE 6. Income tax provisions for fiscal 2021 2020 Year Ended March 31 2021 2020 Current taxes Federal $ 2,600,670 $ 2,710,658 State 75,852 (13,176 ) Deferred taxes Federal (123,959 ) 74,651 State (5,195 ) 3,128 Income tax provision $ 2,547,368 $ 2,775,261 A reconciliation of income tax provisions at the U.S. statutory rate for fiscal 2021 2020 Year Ended March 31 2021 2020 Tax expense at U.S. Statutory rate $ 2,990,768 $ 3,633,400 State income taxes, net of Federal benefit 88,909 77,989 Research and development credits (86,223 ) (126,320 ) Foreign-derived intangible income deduction (450,912 ) (540,265 ) Other 4,826 (269,543 ) Income tax provision $ 2,547,368 $ 2,775,261 Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets and liabilities as of March 31, 2021 2020 March 31 2021 2020 Paid time off accrual $ 60,869 $ 55,240 Inventory reserve 50,324 45,948 Depreciation and amortization 88,690 22,651 Stock-based compensation deductions 75,189 65,218 Unrealized gain on marketable securities (308,403 ) (144,668 ) Other 106,869 63,730 Deferred tax assets $ 73,538 $ 108,119 We had no March 31, 2021, not 12 March 31, 2021 no 2016 2019

Note 7 - Leases

Note 7 - Leases	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Lessee, Operating Leases [Text Block]	NOTE 7. We conduct our operations in a leased facility under a non-cancellable lease expiring March 31, 2026. not Year Ended March 31 2021 2020 Operating lease cost $ 158,439 $ 154,565 Variable lease cost 109,449 96,798 Total $ 267,888 $ 251,363 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for leases $ 133,299 $ 174,528 Remaining lease term (years) 5 6 Discount rate 3.5 % 3.5 % The following table presents the maturities of lease liabilities as of March 31, 2021: Year Ending March 31 Operating Leases 2022 152,703 2023 156,121 2024 159,592 2025 163,224 2026 165,947 Total lease payments 797,587 Imputed lease interest (65,855 ) Total lease liabilities $ 731,732

Note 8 - Concentrations

Note 8 - Concentrations	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	NOTE 8. The following table summarizes customers comprising 10% two % of Revenue for Year Ended March 31 2021 2020 Customer A 22% 24% Customer B 15% 14% Customer C Less than 10% 10% These customers accounted for 43% March 31, 2021 43% March 31, 2020. not

Note 9 - Stock Repurchase Progr

Note 9 - Stock Repurchase Program	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Stock Repurchase Plan Disclosure [Text Block]	NOTE 9. On January 21, 2009 $2,500,000 August 27, 2015, $5,000,000 not not may 1,806 2021 12,972 2020. $3,762,040 March 31, 2021. may

Note 10 - Information as to Emp

Note 10 - Information as to Employee Stock Purchase, Savings, and Similar Plans	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Retirement Benefits [Text Block]	NOTE 10. All of our employees are eligible to participate in our 401 first 21. may 100% first 3% $94,498 2021 $92,880 2020.

Note 11 - Subsequent Events

Note 11 - Subsequent Events	12 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Subsequent Events [Text Block]	NOTE 11. On May 5, 2021 $1.00 May 31, 2021 May 17, 2021.

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents We consider all highly liquid investments with maturities of three
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments The carrying amount of cash and cash equivalents, accounts receivable, and accounts payable approximates fair value because of the short maturity of these instruments. Fair values of marketable securities are based on quoted market prices.
Concentration Of Risk and Financial Instruments Policy [Policy Text Block]	Concentration of Risk and Financial Instruments Financial instruments potentially subject to significant concentrations of credit risk consist principally of cash equivalents, marketable securities, and accounts receivable. Cash and cash equivalents have been maintained in financial institutions we believe have high credit quality, however these accounts are generally in excess of federally insured amounts. We have invested our excess cash in corporate-backed and municipal-backed bonds and money market instruments. Our investment policy prescribes purchases of only high-grade securities, and limits the amount of credit exposure to any one 19 may one Our customers are throughout the world. We generally do not 19 Additionally, we are dependent on critical suppliers including our packaging vendors and suppliers of certain raw silicon and semiconductor wafers that are incorporated in our products. The effects of the COVID- 19
Receivable [Policy Text Block]	Accounts Receivable and Allowance for Doubtful Accounts We grant credit to customers in the normal course of business and at times may no 2021 2020.
Inventory, Policy [Policy Text Block]	Inventories Inventories are stated at the lower of cost or net realizable value. Cost is determined by the first first
Standard Product Warranty, Policy [Policy Text Block]	Product Warranty In general we warranty our products to be free from defects in material and workmanship for one
Property, Plant and Equipment, Policy [Policy Text Block]	Fixed Assets Fixed assets are stated at cost. Depreciation of machinery and equipment is recorded over the estimated useful lives of the assets, generally five five not 2021 2020. $308,511 2021 364,409 2020.
Revenue from Contract with Customer [Policy Text Block]	Revenue Recognition We recognize revenue when we satisfy performance obligations by the transfer of control of products or services to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those products or services. Revenue is disaggregated into product sales and contract research and development to depict the nature, amount, timing of revenue recognition and economic characteristics of our business, and is represented within the financial statements. We recognize revenue from product sales to customers and distributors when we satisfy our performance obligation, at a point in time, on product shipment or delivery to our customer or distributor as determined by agreed on shipping terms. Shipping charges billed to customers are included in product sales and the related shipping costs are included in cost of sales. Under certain limited circumstances, our distributors may third We recognize contract research and development revenue over a period of time as the performance obligation is satisfied over a period of time rather than a point in time. Contracts have specifications unique to each customer and do not Accounts receivable is recognized when we have transferred a good or service to a customer and our right to receive consideration is unconditional through the completion of our performance obligation. A contract asset is recognized when we have a right to consideration from the transfer of goods or services to a customer but have not not no March 31, 2021 March 31, 2020. Our performance obligations related to product sales and contract research and development contracts are satisfied in one one 606, Revenue from Contracts with Customers not not one
Income Tax, Policy [Policy Text Block]	Income Taxes We account for income taxes using the asset and liability method. Deferred income taxes are provided for temporary differences between the financial reporting and tax bases of assets and liabilities. We provide valuation allowances against deferred tax assets if we determine that it is less likely than not
Research and Development Expense, Policy [Policy Text Block]	Research and Development Expense Recognition Research and development costs are expensed as they are incurred. Customer-sponsored research and development costs are included in cost of sales.
Share-based Payment Arrangement [Policy Text Block]	Stock-Based Compensation We measure stock-based compensation cost at the grant date based on the fair value of the award and recognize the compensation expense over the requisite service period, which is generally the vesting period. We recognize any forfeitures as they occur.
Earnings Per Share, Policy [Policy Text Block]	Net Income Per Share Net income per basic share is computed based on the weighted-average number of common shares issued and outstanding during each year. Net income per diluted share amounts assume exercise of all stock options. The following table shows the components of diluted shares: Year Ended March 31 2021 2020 Weighted average common shares outstanding – basic 4,834,054 4,845,627 Dilutive effect of stock options 408 1,667 Shares used in computing net income per share – diluted 4,834,462 4,847,294
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Standards New Accounting Standards Not In December 2019, No. 2019 12, Income Taxes (Topic 740 Simplifying the Accounting for Income Taxes 2019 12 740 2019 12 December 15, 2020 2022 not In June 2016, No. 2016 13, Financial Instruments Credit Losses (Topic 326 2016 13 November 2018 No. 2018 19, Codification Improvements to Topic 326, Credit Losses November 2019, No. 2019 11, Codification Improvements to Topic 326, 2016 13. November 2019 No. 2019 10, Financial Instruments Credit Losses (Topic 326 815 842 February 2020 No. 2020 02, Financial Instruments Credit Losses (Topic 326 842 No. 119 No. 2016 02, 842 2016 13 three March 2020, No. 2020 03, Codification Improvements to Financial Instruments 2019 10 2020 02, 2016 13 December 15, 2022 2024 not

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Weighted Average Number of Shares [Table Text Block]	Year Ended March 31 2021 2020 Weighted average common shares outstanding – basic 4,834,054 4,845,627 Dilutive effect of stock options 408 1,667 Shares used in computing net income per share – diluted 4,834,462 4,847,294

Note 3 - Fair Value of Financ_2

Note 3 - Fair Value of Financial Instruments (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Investments Classified by Contractual Maturity Date [Table Text Block]	Total <1 Year 1 3 Years 3 5 Years $ 64,860,822 $ 17,822,153 $ 36,716,130 $ 10,322,539
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	As of March 31, 2021 As of March 31, 2020 Level 1 Level 2 Total Level 1 Level 2 Total Money market funds $ 10,143,196 $ - $ 10,143,196 $ 7,903,433 $ - $ 7,903,433 Corporate bonds - 54,717,626 54,717,626 - 62,691,309 62,691,309 Total $ 10,143,196 $ 54,717,626 $ 64,860,822 $ 7,903,433 $ 62,691,309 $ 70,594,742
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	As of March 31, 2021 As of March 31, 2020 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Estimated Fair Value Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Estimated Fair Value Money market funds $ 10,143,196 $ - $ - $ 10,143,196 $ 7,903,433 $ - $ - $ 7,903,433 Corporate bonds 53,308,105 1,570,195 (160,674 ) 54,717,626 62,030,120 752,621 (91,432 ) 62,691,309 Total $ 63,451,301 $ 1,570,195 $ (160,674 ) $ 64,860,822 $ 69,933,553 $ 752,621 $ (91,432 ) $ 70,594,742
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block]	Less Than 12 Months 12 Months or Greater Total Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses As of March 31, 2021 Corporate bonds $ 10,322,539 $ (160,674 ) $ - $ - $ 10,322,539 $ (160,674 ) Total $ 10,322,539 $ (160,674 ) $ - $ - $ 10,322,539 $ (160,674 ) As of March 31, 2020 Corporate bonds $ 19,525,169 $ (91,432 ) $ - $ - $ 19,525,169 $ (91,432 ) Total $ 19,525,169 $ (91,432 ) $ - $ - $ 19,525,169 $ (91,432 )

Note 4 - Inventories (Tables)

Note 4 - Inventories (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Inventory, Current [Table Text Block]	March 31 2021 2020 Raw materials $ 660,678 $ 1,017,451 Work in process 2,220,723 1,863,000 Finished goods 1,019,376 1,003,999 Total inventories $ 3,900,777 $ 3,884,450

Note 5 - Stock-based Compensa_2

Note 5 - Stock-based Compensation (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Year Ended March 31 2021 2020 Risk-free interest rate 0.2 – 0.4% 1.7 % Expected volatility 34 – 35% 37 % Expected life (years) 4.6 4.6 Dividend yield 7.0 – 7.4% 5.9 %
Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]	Ranges of Exercise Prices Number Outstanding Weighted Average Exercise Price Weighted Remaining Contractual Life (years) $49.86 – $67.69 22,000 $ 59.85 5.3 $76.13 – $107.86 8,000 92.00 6.9 30,500 $ 68.28 5.7
Share-based Payment Arrangement, Activity [Table Text Block]	Option Shares Reserved Options Outstanding Weighted Average Option Exercise Price At March 31, 2019 135,230 22,000 $ 70.89 Granted (4,000 ) 4,000 $ 67.65 Exercised - (2,000 ) $ 56.18 At March 31, 2020 131,230 24,000 $ 71.58 Granted (6,500 ) 6,500 $ 56.12 At March 31, 2021 124,730 30,500 $ 68.28

Note 6 - Income Taxes (Tables)

Note 6 - Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	Year Ended March 31 2021 2020 Current taxes Federal $ 2,600,670 $ 2,710,658 State 75,852 (13,176 ) Deferred taxes Federal (123,959 ) 74,651 State (5,195 ) 3,128 Income tax provision $ 2,547,368 $ 2,775,261
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Year Ended March 31 2021 2020 Tax expense at U.S. Statutory rate $ 2,990,768 $ 3,633,400 State income taxes, net of Federal benefit 88,909 77,989 Research and development credits (86,223 ) (126,320 ) Foreign-derived intangible income deduction (450,912 ) (540,265 ) Other 4,826 (269,543 ) Income tax provision $ 2,547,368 $ 2,775,261
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	March 31 2021 2020 Paid time off accrual $ 60,869 $ 55,240 Inventory reserve 50,324 45,948 Depreciation and amortization 88,690 22,651 Stock-based compensation deductions 75,189 65,218 Unrealized gain on marketable securities (308,403 ) (144,668 ) Other 106,869 63,730 Deferred tax assets $ 73,538 $ 108,119

Note 7 - Leases (Tables)

Note 7 - Leases (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Lease, Cost [Table Text Block]	Year Ended March 31 2021 2020 Operating lease cost $ 158,439 $ 154,565 Variable lease cost 109,449 96,798 Total $ 267,888 $ 251,363 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for leases $ 133,299 $ 174,528 Remaining lease term (years) 5 6 Discount rate 3.5 % 3.5 %
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Year Ending March 31 Operating Leases 2022 152,703 2023 156,121 2024 159,592 2025 163,224 2026 165,947 Total lease payments 797,587 Imputed lease interest (65,855 ) Total lease liabilities $ 731,732

Note 8 - Concentrations (Tables

Note 8 - Concentrations (Tables)	12 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	% of Revenue for Year Ended March 31 2021 2020 Customer A 22% 24% Customer B 15% 14% Customer C Less than 10% 10%

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Credit Loss Expense (Reversal)	$ 0	$ 0
Product Warranty Term (Year)		1 year
Impairment of Long-Lived Assets Held-for-use	0	$ 0
Depreciation, Depletion and Amortization, Nonproduction, Total	$ 308,511	$ 364,409
Machinery and Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years
Leasehold Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Weighted Average Number of Shares (Details) - shares	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Basic (in shares)	4,834,054	4,845,627
Dilutive effect of stock options (in shares)	408	1,667
Shares used in computing net income per share – diluted (in shares)	4,834,462	4,847,294

Note 3 - Fair Value of Financ_3

Note 3 - Fair Value of Financial Instruments (Details Textual)	12 Months Ended
	Mar. 31, 2021
Available for Sale Debt Securitites, Percent of Total Assets	89.00%
Number of Other-than-temporarily Impaired Available-for-sale Securities	0
Number of Other-than-temporarily Impaired Marketable Securities	0
Minimum [Member]
Available for Sale Debt Securities, Remaining Maturity (Week)	140 days
Maximum [Member]
Available for Sale Debt Securities, Remaining Maturity (Week)	3 years 330 days

Note 3 - Fair Value of Financ_4

Note 3 - Fair Value of Financial Instruments - Fair Value of Available-for-sale Securities (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Total	$ 64,860,822	$ 70,594,742
Less than 1 year	17,822,153
1-3 years	36,716,130
3-5 years	$ 10,322,539

Note 3 - Fair Value of Financ_5

Note 3 - Fair Value of Financial Instruments - Assets Measured on Recurring Basis (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Total	$ 64,860,822	$ 70,594,742
Money Market Funds [Member]
Total	10,143,196	7,903,433
Corporate Bond Securities [Member]
Total	54,717,626	62,691,309
Fair Value, Recurring [Member]
Total	64,860,822	70,594,742
Fair Value, Recurring [Member] | Money Market Funds [Member]
Total	10,143,196	7,903,433
Fair Value, Recurring [Member] | Corporate Bond Securities [Member]
Total	54,717,626	62,691,309
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Total	10,143,196	7,903,433
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Total	10,143,196	7,903,433
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Bond Securities [Member]
Total
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Total	54,717,626	62,691,309
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Total
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bond Securities [Member]
Total	$ 54,717,626	$ 62,691,309

Note 3 - Fair Value of Financ_6

Note 3 - Fair Value of Financial Instruments - Reconciliation of Available-for-sale Securities (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Amortized Cost	$ 63,451,301	$ 69,933,553
Gross Unrealized Holding Gains	1,570,195	752,621
Gross Unrealized Holding Losses	(160,674)	(91,432)
Estimated Fair Value	64,860,822	70,594,742
Money Market Funds [Member]
Amortized Cost	10,143,196	7,903,433
Gross Unrealized Holding Gains
Gross Unrealized Holding Losses
Estimated Fair Value	10,143,196	7,903,433
Corporate Bond Securities [Member]
Amortized Cost	53,308,105	62,030,120
Gross Unrealized Holding Gains	1,570,195	752,621
Gross Unrealized Holding Losses	(160,674)	(91,432)
Estimated Fair Value	$ 54,717,626	$ 62,691,309

Note 3 - Fair Value of Financ_7

Note 3 - Fair Value of Financial Instruments - Investment Securities With Unrealized Losses (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Fair market value, less than 12 months	$ 10,322,539	$ 19,525,169
Gross unrealized losses, less than 12 months	(160,674)	(91,432)
Fair market value, 12 months or greater
Gross unrealized losses, 12 months or greater
Total fair market value	10,322,539	19,525,169
Total gross unrealized losses	(160,674)	(91,432)
Corporate Bond Securities [Member]
Fair market value, less than 12 months	10,322,539	19,525,169
Gross unrealized losses, less than 12 months	(160,674)	(91,432)
Fair market value, 12 months or greater
Gross unrealized losses, 12 months or greater
Total fair market value	10,322,539	19,525,169
Total gross unrealized losses	$ (160,674)	$ (91,432)

Note 4 - Inventories - Summary

Note 4 - Inventories - Summary of Inventories (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Raw materials	$ 660,678	$ 1,017,451
Work in process	2,220,723	1,863,000
Finished goods	1,019,376	1,003,999
Total inventories	$ 3,900,777	$ 3,884,450

Note 5 - Stock-based Compensa_3

Note 5 - Stock-based Compensation (Details Textual) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	5 years
Share-based Payment Arrangement, Expense	$ 45,572	$ 48,360
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		5.90%
Share-based Payment Arrangement, Exercise of Option, Tax Benefit	$ 9,971	$ 10,581
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Year)	5 years 255 days	6 years 219 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)	28,000	24,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 230,540
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	191,140
Share-based Compensation Arrangement by Share Based Payment Award Options Grants in Period Fair Value	47,140
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 1,568
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	7.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	7.40%

Note 5 - Stock-based Compensa_4

Note 5 - Stock-based Compensation - Schedule of Valuation Assumptions (Details)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Risk-free interest rate		1.70%
Expected volatility		37.00%
Expected life (years) (Year)	4 years 219 days	4 years 219 days
Dividend yield		5.90%
Minimum [Member]
Risk-free interest rate	0.20%
Expected volatility	34.00%
Dividend yield	7.00%
Maximum [Member]
Risk-free interest rate	0.40%
Expected volatility	35.00%
Dividend yield	7.40%

Note 5 - Stock-based Compensa_5

Note 5 - Stock-based Compensation - Summary of Options Outstanding (Details)	12 Months Ended
	Mar. 31, 2021$ / sharesshares
Number outstanding (in shares) | shares	30,500
Weighted average exercise price (in dollars per share)	$ 68.28
Weighted average contractual life (Year)	5 years 255 days
Range One [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 49.86
Range of exercise prices, upper limit (in dollars per share)	$ 67.69
Number outstanding (in shares) | shares	22,000
Weighted average exercise price (in dollars per share)	$ 59.85
Weighted average contractual life (Year)	5 years 109 days
Range Two [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 76.13
Range of exercise prices, upper limit (in dollars per share)	$ 107.86
Number outstanding (in shares) | shares	8,000
Weighted average exercise price (in dollars per share)	$ 92
Weighted average contractual life (Year)	6 years 328 days

Note 5 - Stock-based Compensa_6

Note 5 - Stock-based Compensation - Summary of Stock Options (Details) - $ / shares	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Option Shares Reserved [Member]
Option shares reserved (in shares)	124,730	131,230	135,230
Granted (in shares)	(6,500)	(4,000)
Granted (in shares)	6,500	4,000
Exercised (in shares)
Exercised (in shares)
Share-based Payment Arrangement, Option [Member]
Option shares reserved (in shares)	30,500	24,000	22,000
Weighted average option exercise price (in dollars per share)	$ 68.28	$ 71.58	$ 70.89
Granted (in shares)	(6,500)	(4,000)
Granted (in shares)	6,500	4,000
Granted, weighted average option exercise price (in dollars per share)	$ 56.12	$ 67.65
Exercised (in shares)		2,000
Exercised (in shares)		(2,000)
Exercised, weighted average option exercise price (in dollars per share)		$ 56.18

Note 6 - Income Taxes (Details

Note 6 - Income Taxes (Details Textual) $ in Thousands	12 Months Ended
	Mar. 31, 2021USD ($)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 0
Open Tax Year	2016 2017 2018 2019

Note 6 - Income Taxes - Schedul

Note 6 - Income Taxes - Schedule of Income Tax Provisions (Details) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Current taxes
Federal, Current taxes	$ 2,600,670	$ 2,710,658
State, Current taxes	75,852	(13,176)
Deferred taxes
Federal, Deferred taxes	(123,959)	74,651
State, Deferred taxes	(5,195)	3,128
Income tax provision	$ 2,547,368	$ 2,775,261

Note 6 - Income Taxes - Reconci

Note 6 - Income Taxes - Reconciliation of Income Tax Provisions (Details) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Tax expense at U.S. Statutory rate	$ 2,990,768	$ 3,633,400
State income taxes, net of Federal benefit	88,909	77,989
Research and development credits	(86,223)	(126,320)
Foreign-derived intangible income deduction	(450,912)	(540,265)
Other	4,826	(269,543)
Income tax provision	$ 2,547,368	$ 2,775,261

Note 6 - Income Taxes - Deferre

Note 6 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Paid time off accrual	$ 60,869	$ 55,240
Inventory reserve	50,324	45,948
Depreciation and amortization	88,690	22,651
Stock-based compensation deductions	75,189	65,218
Unrealized gain on marketable securities	(308,403)	(144,668)
Other	106,869	63,730
Deferred tax assets	$ 73,538	$ 108,119

Note 7 - Leases - Operating Lea

Note 7 - Leases - Operating Lease (Details) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating lease cost	$ 158,439	$ 154,565
Variable lease cost	109,449	96,798
Total	267,888	251,363
Operating cash flows for leases	$ 133,299	$ 174,528
Remaining lease term (Month)	150 days	180 days
Discount rate	3.50%	3.50%

Note 7 - Leases - Maturities of

Note 7 - Leases - Maturities of Lease Liabilities (Details)	Mar. 31, 2021USD ($)
2022	$ 152,703
2023	156,121
2024	159,592
2025	163,224
2026	165,947
Total lease payments	797,587
Imputed lease interest	(65,855)
Total lease liabilities	$ 731,732

Note 8 - Concentrations (Detail

Note 8 - Concentrations (Details Textual)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage	43.00%	43.00%

Note 8 - Concentrations - Reven

Note 8 - Concentrations - Revenue by Major Customers (Details) - Revenue Benchmark [Member] - Customer Concentration Risk [Member]	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Customer A [Member]
Percentage of concentration	22.00%	24.00%
Customer B [Member]
Percentage of concentration	15.00%	14.00%
Customer C [Member[
Percentage of concentration	10.00%	10.00%

Note 9 - Stock Repurchase Pro_2

Note 9 - Stock Repurchase Program (Details Textual) - Repurchase Program 2009 [Member] - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Aug. 27, 2015	Jan. 21, 2009
Stock Repurchase Program, Authorized Amount				$ 2,500,000
Stock Repurchase Program Authorized Additional Amount			$ 5,000,000
Stock Repurchased During Period, Shares (in shares)	1,806	12,972
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 3,762,040

Note 10 - Information as to E_2

Note 10 - Information as to Employee Stock Purchase, Savings, and Similar Plans (Details Textual) - USD ($)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	3.00%
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 94,498	$ 92,880

Note 11 - Subsequent Events (De

Note 11 - Subsequent Events (Details Textual) - $ / shares	May 05, 2021	Mar. 31, 2021	Mar. 31, 2020
Common Stock, Dividends, Per Share, Declared (in dollars per share)		$ 4	$ 4
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared (in dollars per share)	$ 1