AO241 Solid State Relay SPST-NO Equivalent & Substitute Parts

Part Overview

The AO241 is a solid state relay (SSR) manufactured by Sensata-Crydom, configured as a single-pole single-throw normally open (SPST-NO) device in a 4-SIP package. This component switches AC loads up to 1A at 24–280V with a 4–10VDC input signal and incorporates zero-cross detection for AC switching applications.

The AO241 is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support legacy system maintenance or redesign initiatives.

Substiute Parts

AO241

Sensata-CrydomIn Stock: 1065AO241 Datasheet

Current PartRFQ

ASO241

Sensata-CrydomIn Stock: 1255ASO241 Datasheet

DirectRFQ

ASO242

Sensata TechnologiesIn Stock: 1299ASO242 Datasheet

DirectRFQ

AQG12205

Panasonic Electric WorksIn Stock: 2433AQG12205 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the AO241 is determined by the following critical parameters:

• Circuit Configuration: Must be SPST-NO (1 Form A)
• Package / Case: Must be 4-SIP to ensure mechanical and electrical compatibility with existing PCB layouts
• Mounting Type: Must be Through Hole
• Termination Style: Must be PC Pin
• Output Type: Must support AC switching with zero-cross detection
• Input Voltage Range: Must accommodate 4–10VDC control signals
• Load Voltage Range: Must cover or exceed 24–280V operation
• Load Current: Must be rated for minimum 1A continuous operation

The substitute parts identified below meet these core compatibility criteria. Variations in load current rating (1A, 1.5A, or 2A) and load voltage minimum thresholds (24V, 12V, or 75V) represent functional enhancements that maintain backward compatibility with the original AO241 design.

Parameter Comparison

Engineering Selection Recommendations

ASO241 (Sensata-Crydom): This part is the direct successor within the Sensata-Crydom product line. It maintains identical input voltage, package, and mounting specifications while offering increased load current capacity (1.5A vs. 1A) and extended lower load voltage threshold (12V vs. 24V). Product status is Active with ROHS3 compliance. This is the primary recommendation for direct replacement in active production designs.

ASO242 (Sensata Technologies): This variant provides the highest load current rating (2A) among available substitutes, maintaining the same input voltage and package configuration. Product status is Active with ROHS3 compliance. Selection of this part is appropriate when design margins or future load growth require additional current capacity.

AQG12205 (Panasonic Electric Works): This part is a cross-manufacturer substitute from Panasonic Electric Works. It maintains the 1A load current rating and 4-SIP package but operates with a narrower input voltage range (4–6VDC vs. 4–10VDC) and a different load voltage window (75–264V vs. 24–280V). Product status is Active with ROHS3 compliance. This part is suitable only when the application load voltage naturally falls within the 75–264V range and input control voltage is constrained to 4–6VDC.

All three substitutes are currently in active production status, ensuring long-term supply availability compared to the obsolete AO241.

Frequently Asked Questions (FAQ)

Q: Can ASO241 or ASO242 be used as direct drop-in replacements for AO241?

A: Yes. Both ASO241 and ASO242 share identical package (4-SIP), mounting type (Through Hole), termination style (PC Pin), circuit configuration (SPST-NO), and input voltage range (4–10VDC) with the AO241. They require no PCB layout modifications. The increased load current ratings (1.5A and 2A respectively) provide functional enhancement without compatibility issues.

Q: What is the key difference between ASO241 and ASO242?

A: The primary difference is load current rating. ASO241 is rated for 1.5A continuous, while ASO242 is rated for 2A continuous. Both operate across 12–280V load voltage range. Selection depends on whether the application requires the additional 0.5A margin provided by ASO242.

Q: Why does AQG12205 have a narrower input voltage range (4–6VDC)?

A: AQG12205 is manufactured by Panasonic Electric Works using different internal design specifications. The 4–6VDC input range is a design characteristic of this product line. Applications using input voltages above 6VDC cannot use this part.

Q: Can AQG12205 be used in applications requiring 24V load voltage?

A: No. AQG12205 is rated for 75–264V load voltage. Applications requiring operation at 24V load voltage must use ASO241 or ASO242, which are rated for 12–280V.

Q: What is the significance of ROHS3 compliance on ASO241 and ASO242?

A: ROHS3 compliance indicates these parts meet Restriction of Hazardous Substances Directive requirements and are suitable for use in regulated markets including the European Union. This is a regulatory advantage over the AO241, which has no specified RoHS status.

Q: Are there inventory considerations when selecting a substitute?

A: Yes. ASO241 has 1155 units in stock, ASO242 has 1241 units in stock, and AQG12205 has 2338 units in stock. All three substitutes are available in quantity. The obsolete AO241 has 1039 units remaining in inventory.