FLEX-14-35-40 Glass Body Reed Switch Equivalent & Substitute Parts

Part Overview

The FLEX-14-35-40 is a glass body reed switch manufactured by Littelfuse Inc., configured as a single-pole single-throw normally open (SPST-NO) device. This through-hole component is rated for 350mA AC / 500mA DC switching at 140V AC and 200V DC, with a 10W power rating. The part is currently active in production with full RoHS3 compliance and unlimited moisture sensitivity rating (MSL 1).

Equivalent and substitute parts are identified when component availability is limited, supply chain disruptions occur, or design flexibility is required while maintaining functional compatibility within specified electrical and mechanical parameters.

Substiute Parts

FLEX-14-35-40

Littelfuse Inc.In Stock: 1495FLEX-14-35-40 Datasheet

Current PartRFQ

KSK-1A66/3-2030

Standex-Meder ElectronicsIn Stock: 1307KSK-1A66/3-2030 Datasheet

MFR RecommendedRFQ

SW GP560/10-15 AT

Standex-Meder ElectronicsIn Stock: 3413SW GP560/10-15 AT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FLEX-14-35-40 are qualified based on the following criteria:

Electrical Compatibility Parameters:

• Circuit configuration must be SPST-NO
• Switching current capability must meet or exceed 350mA AC / 500mA DC
• Switching voltage must support minimum 140V AC / 200V DC operation
• Power rating must be 10W or greater
• Operating temperature range must encompass -40°C to 125°C

Mechanical Compatibility Parameters:

• Mounting type must be Through Hole
• Termination style must be Axial
• Physical dimensions must be compatible with existing PCB layouts

Compliance Requirements:

• RoHS3 compliance required
• MSL rating of 1 (Unlimited) required
• Active product status preferred

Two substitute parts meet these criteria and are listed below.

Parameter Comparison

Engineering Selection Recommendations

KSK-1A66/3-2030 (Standex-Meder Electronics)

This substitute provides direct electrical compatibility with the FLEX-14-35-40. The KSK-1A66/3-2030 exceeds the switching current requirement (500mA AC/DC vs. 350mA AC / 500mA DC) and maintains identical 200V DC switching voltage. Physical dimensions are identical (1.744" overall length, 44.30mm), enabling direct PCB layout compatibility. Operating temperature range extends to 130°C, providing additional thermal margin. All compliance certifications match the main part. This substitute is recommended for applications requiring identical form factor and enhanced current handling.

SW GP560/10-15 AT (Standex-Meder Electronics)

This substitute provides enhanced current switching capability (1A AC/DC) and increased carry current (1.5A AC/DC). The GP560 series supports 200V AC switching voltage, exceeding the main part's 140V AC requirement. However, DC switching voltage is rated at 100V, which is below the main part's 200V DC specification. Overall length is 2.126" (54.00mm), requiring PCB layout verification. This substitute is suitable for applications where DC switching voltage does not exceed 100V and where increased current capacity is beneficial.

Frequently Asked Questions (FAQ)

Q: Can KSK-1A66/3-2030 be used as a direct replacement for FLEX-14-35-40?

A: Yes. The KSK-1A66/3-2030 maintains identical physical dimensions (1.744" length), identical circuit configuration (SPST-NO), and meets or exceeds all electrical parameters. Switching current is 500mA (AC/DC) versus the main part's 350mA (AC) / 500mA (DC). DC switching voltage is identical at 200V. No PCB layout modifications are required.

Q: What are the limitations of SW GP560/10-15 AT as a substitute?

A: The SW GP560/10-15 AT has a DC switching voltage rating of 100V, which is lower than the FLEX-14-35-40's 200V DC specification. This substitute is only suitable for applications where the DC switching voltage requirement does not exceed 100V. Additionally, the overall length is 2.126" (54.00mm) compared to 1.744" (44.30mm), requiring verification of available PCB space.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. Both KSK-1A66/3-2030 and SW GP560/10-15 AT are ROHS3 compliant with MSL 1 (Unlimited) rating, matching the main part's compliance profile.

Q: What is the difference between AC and DC switching current ratings?

A: The FLEX-14-35-40 specifies 350mA for AC switching and 500mA for DC switching. The KSK-1A66/3-2030 specifies 500mA for both AC and DC, providing uniform current handling across both modes. The SW GP560/10-15 AT also specifies 1A for both AC and DC operation.

Q: Do the substitute parts have different operate and release times?

A: Yes. The FLEX-14-35-40 has an operate time of 0.55ms and release time of 0.2ms. The KSK-1A66/3-2030 has an operate time of 0.7ms and release time of 0.05ms. The SW GP560/10-15 AT has an operate time of 0.6ms and release time of 0.1ms. Applications with strict timing requirements should account for these differences.

Q: Can packaging type affect substitution decisions?

A: The FLEX-14-35-40 is supplied in Box packaging, while both substitutes are supplied in Bulk packaging. This affects inventory management and handling procedures but does not impact electrical or mechanical compatibility.