Littelfuse FS312 - The FS300 Series of solid-state flashers were specifically designed to operate lamp loads. Their two-terminal series connection feature makes installation easy. The high immunity to line noise and transients makes the FS300 Series ideal for moving vehicle applications. All solid-state construction means reliability and long life. The FS300 Series offers a factory fixed flash rate of 75 FPM or may be ordered with a fixed, custom flash rate ranging from 60 to 150 FPM. Operation: Upon application of input voltage, the T2 OFF time begins. At the end of the OFF time, the T1 ON time begins and the load energizes. At the end of T1, T2 begins and the load de-energizes. This cycle repeats until input voltage is removed. Reset: Removing input voltage resets the output and the sequence to T2.
Littelfuse

FS312

Alternate Item Number: FS312

UPC: 079458993547

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Overview

The Littelfuse FS312 solid-state flasher is a high-performance, two-terminal series-connected device engineered for reliable lamp load operation in demanding industrial and automotive applications. Designed to meet the rigorous demands of moving vehicle systems, this encapsulated flasher delivers exceptional durability with no moving parts to wear out over time, ensuring long service life even in harsh environments with shock, vibration, and humidity exposure. The FS312 operates with a factory-fixed flash rate of 75 flashes per minute (FPM) with a ±10% tolerance, providing consistent signaling for safety and visibility applications. Alternatively, custom flash rates between 60 and 150 FPM are available to meet specific application requirements, offering flexibility for diverse lighting control needs. Engineered with high immunity to line noise and transients, the FS312 is ideally suited for automotive, marine, construction, and industrial equipment where electrical noise and voltage fluctuations are common. Its two-terminal series connection simplifies installation in both new and retrofit applications, eliminating the need for complex wiring configurations. The flasher’s high surge current capability—up to 10 times the steady-state rating—ensures reliable operation even with incandescent lamp loads, which are known for high inrush currents during startup. The ON/OFF ratio is approximately 50%, providing balanced flash timing for optimal visibility and energy efficiency. The FS312 supports input voltages of 12VDC ±20%, making it compatible with standard 12V automotive and industrial systems. With a maximum load rating of 2.5A, it is capable of driving incandescent or resistive lamp loads directly, reducing the need for additional relays or control circuitry. The solid-state construction is fully encapsulated, protecting internal components from environmental contaminants and mechanical stress. This design not only enhances reliability but also simplifies maintenance, as there are no contacts to clean or replace. Typical applications include emergency vehicle lighting, construction equipment warning lights, agricultural machinery signal lamps, and industrial signaling systems. The FS312 is also well-suited for use in marine environments, where resistance to moisture and vibration is critical. For installation flexibility, Littelfuse offers a range of accessories, including mounting brackets, quick-connect terminals, and DIN rail adapters, allowing the flasher to be integrated into virtually any control panel or vehicle electrical system. The P1023-6 mounting bracket enables quick and secure attachment, while the P1015-64 female quick-connect terminals provide strain relief for reliable electrical connections. Littelfuse, a global leader in circuit protection and industrial control solutions, has built a reputation for delivering high-quality, reliable components trusted by engineers and technicians worldwide. The FS300 Series, including the FS312, reflects the company’s commitment to innovation and durability, ensuring that critical signaling applications remain operational under the most challenging conditions. Whether for OEM integration or aftermarket upgrades, the FS312 solid-state flasher provides a dependable, long-lasting solution for lamp load flashing requirements.
  • Two-terminal series connection for easy installation in new or existing systems
  • Factory-fixed 75 FPM flash rate (±10% tolerance) or custom rates from 60 to 150 FPM
  • High immunity to line noise and transients—ideal for moving vehicle applications
  • Encapsulated solid-state design with no moving parts for long life and durability
  • Supports 12VDC input with 2.5A maximum load rating for incandescent or resistive lamps
  • High surge current capability (10x steady state) for reliable lamp load operation
  • Compatible with accessories like mounting brackets, quick-connect terminals, and DIN rail adapters
  • Fully encapsulated for protection against shock, vibration, and humidity

Specifications

Brand Name
Littelfuse
Connection
Surface mount with one #10 (M5 x 0.8) screw
Connection Type
Two-terminal series connection
Current Rating
2.5A
Frequency
75 FPM
Material
Solid-state encapsulated
Mounting
Surface mount with one #10 (M5 x 0.8) screw Mount
Operating Temperature
-20 to 60 F
Operating Temperature, Maximum
60 F
Operating Temperature, Minimum
-20 F
Series
FS300
Special Features
10Y WARR
Standard
CE/UR/CSA
Sub Brand
SSAC
Voltage Rating
12VDC
The FS100 Series (medium power) may be used to control inductive, incandescent, or resistive loads. Input voltages of 24, 120, or 230VAC are available. Fixed flash rates in stock range from 30, 50, 60, and 90 FPM, with custom flash rates ranging from 10 to 300 FPM. Encapsulation provides protection against shock, vibration, and humidity. This group of solid-state flashers has proven reliability with years of use throughout the world.

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Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.