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  <xsd:element abstract="true" id="sodi_EuropeAndAustraliaMember" name="EuropeAndAustraliaMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_FinishedGoodsMember" name="FinishedGoodsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_IncreaseDecreaseInContingentConsiderationLiability" name="IncreaseDecreaseInContingentConsiderationLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration"/>
  <xsd:element id="sodi_IncreaseDecreaseInSalesReturnsAllowance" name="IncreaseDecreaseInSalesReturnsAllowance" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_IntracomDefenseElectronicsMember" name="IntracomDefenseElectronicsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_L3harrisMember" name="L3harrisMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_LesseeFinanceLeaseOptionToPurchasePurchaseAmount" name="LesseeFinanceLeaseOptionToPurchasePurchaseAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_MicroEngineeringIncMember" name="MicroEngineeringIncMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_MicroPropertyMember" name="MicroPropertyMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_NinetyDaysAfterAgreementDateMember" name="NinetyDaysAfterAgreementDateMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_NoncurrentSecuritiesMember" name="NoncurrentSecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_NonmilitaryScientificIndustrialCustomersAndDistributorsMember" name="NonmilitaryScientificIndustrialCustomersAndDistributorsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_NoteToFinancialStatementDetailsTextual" name="NoteToFinancialStatementDetailsTextual" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_NotesToFinancialStatements" name="NotesToFinancialStatements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_NotesToFinancialStatementsAbstract" name="NotesToFinancialStatementsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_OneDistributorMember" name="OneDistributorMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_OneSecurityMember" name="OneSecurityMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_OperatingLossCarryforwardsNotSubjectToExpiration" name="OperatingLossCarryforwardsNotSubjectToExpiration" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant"/>
  <xsd:element id="sodi_OperatingLossCarryforwardsSubjectToExpiration" name="OperatingLossCarryforwardsSubjectToExpiration" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant"/>
  <xsd:element abstract="true" id="sodi_PolicyTable" name="PolicyTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_ProfitSharingPlanMember" name="ProfitSharingPlanMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_PropertyInWestPalmBeachFloridaMember" name="PropertyInWestPalmBeachFloridaMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_RateOfGrossRevenuePaidToShareholders" name="RateOfGrossRevenuePaidToShareholders" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_RelatedPartyTransactionsPolicyTextBlock" name="RelatedPartyTransactionsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_RtxCorporationMember" name="RtxCorporationMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_SalesReturnsAndAllowanceAccrualAllowancesAccrued" name="SalesReturnsAndAllowanceAccrualAllowancesAccrued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element id="sodi_SalesReturnsAndAllowanceAccrualCreditsIssued" name="SalesReturnsAndAllowanceAccrualCreditsIssued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element id="sodi_SalesReturnsAndAllowancesAccrualActivityTableTextBlock" name="SalesReturnsAndAllowancesAccrualActivityTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_ScheduleOfEstimatedUsefulLifeOfPropertyPlantAndEquipmentTableTextBlock" name="ScheduleOfEstimatedUsefulLifeOfPropertyPlantAndEquipmentTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element id="sodi_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodFairValue" name="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodFairValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration"/>
  <xsd:element id="sodi_ShippingAndHandlingCostsPolicyTextBlock" name="ShippingAndHandlingCostsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_SupplierOneMember" name="SupplierOneMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_SupplierTwoMember" name="SupplierTwoMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_TaxYear2029Member" name="TaxYear2029Member" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_TaxYear2037Member" name="TaxYear2037Member" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_TaxYear2038Member" name="TaxYear2038Member" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_TwoSuppliersMember" name="TwoSuppliersMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_UseableOfficeAndProductionSpaceInOrangeCountyFloridaMember" name="UseableOfficeAndProductionSpaceInOrangeCountyFloridaMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_UsedEquipmentPurchasedFromEsComponentsMember" name="UsedEquipmentPurchasedFromEsComponentsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_WaferBankInventoryMember" name="WaferBankInventoryMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_Within30DaysAfterTheEndOfEachFiscalQuarterMember" name="Within30DaysAfterTheEndOfEachFiscalQuarterMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_WorkinprocessMember" name="WorkinprocessMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-12-disaggregation-of-revenue-and-major-customers-tables" name="statement-statement-note-12-disaggregation-of-revenue-and-major-customers-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-12-disaggregation-of-revenues-and-major-customers-schedule-of-revenue-from-external-customers-and-longlived-assets-by-geographical-areas-details" name="statement-statement-note-12-disaggregation-of-revenues-and-major-customers-schedule-of-revenue-from-external-customers-and-longlived-assets-by-geographical-areas-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-15-notes-payable-principal-payments-details" name="statement-statement-note-15-notes-payable-principal-payments-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-15-notes-payable-tables" name="statement-statement-note-15-notes-payable-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-2-summary-of-significant-accounting-policies-roll-forward-of-contingent-consideration-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-roll-forward-of-contingent-consideration-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-2-summary-of-significant-accounting-policies-schedule-of-fair-value-assets-and-liabilities-measured-on-recurring-basis-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-schedule-of-fair-value-assets-and-liabilities-measured-on-recurring-basis-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-2-summary-of-significant-accounting-policies-schedule-of-property-plant-and-equipment-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-schedule-of-property-plant-and-equipment-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-2-summary-of-significant-accounting-policies-summary-of-marketable-securities-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-summary-of-marketable-securities-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-2-summary-of-significant-accounting-policies-summary-of-noncurrent-securities-details" name="statement-statement-note-2-summary-of-significant-accounting-policies-summary-of-noncurrent-securities-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-2-summary-of-significant-accounting-policies-tables" name="statement-statement-note-2-summary-of-significant-accounting-policies-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-3-acquisition-of-micro-engineering-inc-schedule-of-contingent-consideration-details" name="statement-statement-note-3-acquisition-of-micro-engineering-inc-schedule-of-contingent-consideration-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-3-acquisition-of-micro-engineering-inc-tables" name="statement-statement-note-3-acquisition-of-micro-engineering-inc-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-4-intangible-assets-schedule-of-amortization-of-finitelived-intangible-assets-details" name="statement-statement-note-4-intangible-assets-schedule-of-amortization-of-finitelived-intangible-assets-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-4-intangible-assets-schedule-of-finitelived-intangible-assets-details" name="statement-statement-note-4-intangible-assets-schedule-of-finitelived-intangible-assets-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-4-intangible-assets-tables" name="statement-statement-note-4-intangible-assets-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-5-revenue-recognition-schedule-of-sales-returns-and-allowances-and-accrual-activity-details" name="statement-statement-note-5-revenue-recognition-schedule-of-sales-returns-and-allowances-and-accrual-activity-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-5-revenue-recognition-tables" name="statement-statement-note-5-revenue-recognition-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-6-inventories-schedule-of-inventory-details" name="statement-statement-note-6-inventories-schedule-of-inventory-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-6-inventories-tables" name="statement-statement-note-6-inventories-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-7-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details" name="statement-statement-note-7-property-plant-and-equipment-schedule-of-property-plant-and-equipment-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-7-property-plant-and-equipment-tables" name="statement-statement-note-7-property-plant-and-equipment-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-8-accrued-expenses-and-other-current-liabilities-schedule-of-accounts-payable-and-accrued-liabilities-details" name="statement-statement-note-8-accrued-expenses-and-other-current-liabilities-schedule-of-accounts-payable-and-accrued-liabilities-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-8-accrued-expenses-and-other-current-liabilities-tables" name="statement-statement-note-8-accrued-expenses-and-other-current-liabilities-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-9-income-taxes-reconciliation-of-effective-tax-rate-details" name="statement-statement-note-9-income-taxes-reconciliation-of-effective-tax-rate-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-9-income-taxes-schedule-of-deferred-tax-assets-and-liabilities-details" name="statement-statement-note-9-income-taxes-schedule-of-deferred-tax-assets-and-liabilities-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-9-income-taxes-summary-of-net-operating-loss-carryforwards-details" name="statement-statement-note-9-income-taxes-summary-of-net-operating-loss-carryforwards-details" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-note-9-income-taxes-tables" name="statement-statement-note-9-income-taxes-tables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
  <xsd:element abstract="true" id="sodi_statement-statement-significant-accounting-policies-policies" name="statement-statement-significant-accounting-policies-policies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration"/>
</xsd:schema>
