Relay 12VDC 3A 5Pin HK4101F

The HK4101F 12VDC 3A Relay is a compact electromechanical switching component designed to control electrical circuits using a low-voltage DC control signal. Its five-pin configuration combines a 12V DC coil with a single-pole double-throw (SPDT) contact arrangement, allowing one circuit to switch between two contact states. The relay is suitable for PCB-mounted electronic circuits, control boards, and embedded-system applications.

When 12V DC is applied to the relay coil, the resulting magnetic field moves the internal contact mechanism from its normal position to the energized position. When the coil is de-energized, the contacts return to their original state. This operating principle enables electrical switching between normally closed (NC) and normally open (NO) contacts.

The HK4101F supports a 3A contact rating, with commonly specified ratings of 250V AC and 30V DC. Its compact construction makes it useful for switching small electrical loads, control signals, indicators, and suitable low-power equipment. The relay's contact rating must be considered separately from its 12V coil voltage, as the coil operates the relay while the contacts switch the external circuit.

The relay features a through-hole PCB mounting design and a compact body measuring approximately 15.5 × 10.5 × 11.8mm. This allows integration into electronic control boards where mounting space is limited. Its silver-alloy contact material supports electrical switching, while the sealed or flux-proof construction available in some versions can help protect the internal mechanism during assembly.

For microcontroller-based projects, the relay can be controlled using a suitable transistor or MOSFET driver stage. A flyback diode should generally be connected across the DC coil when using a semiconductor driver, with correct polarity, to suppress the inductive voltage generated when the coil is switched off. The coil should not be powered directly from a typical Arduino or microcontroller GPIO pin.

The HK4101F is suitable for electronic prototyping, low-power automation, interface circuits, and general-purpose PCB switching applications where a compact 12V relay is required.

Features

• 12V DC relay coil

• 3A contact switching capability

• Five-pin PCB mounting configuration

• SPDT changeover contact arrangement

• Normally open and normally closed contacts

• Compact electromechanical construction

• Silver-alloy contact material

• Suitable for electronic control circuits

• Compatible with transistor or MOSFET driver stages

Specifications

Electrical ratings and dimensions are based on commonly published HK4101F datasheets. Confirm the exact manufacturer suffix and version before using these values in a safety-critical or production design.

Applications

• PCB-based electronic switching

• Embedded control systems

• Microcontroller relay interfaces

• Low-power automation circuits

• Electronic equipment control

• Indicator and signal switching

• Control panels

• DIY electronics projects

• General-purpose electrical switching

• Prototype and development boards