Hongfa Signal Relays

Selecting a Hongfa signal relay for low-level switching requires attention to different parameters than power relays: Contact Material - precious metal contacts (gold or silver alloy) are essential for reliable low-level switching below 1A

gold-plated contacts prevent oxidation and ensure consistent contact resistance

Contact Resistance - look for low contact resistance (50-100mΩ) to minimize signal attenuation

signal relays typically have lower contact resistance than power relays

Thermal EMF - low thermal EMF is critical for thermocouple and measurement applications

select relays designed for instrumentation

Coil Sensitivity - high sensitivity coils (100-200mW) reduce power consumption in multi-relay designs

Size Constraints - ultra-miniature packages enable high-density layouts

consider height restrictions for compact equipment

Contact Configuration - DPDT relays provide more switching flexibility for multiplexers

Signal Integrity - sealed construction prevents contamination that could affect contact performance. For audio applications, consider relays with low capacitance between contacts. For telecommunications, verify the relay meets relevant industry standards.

Select signal relays with precious metal contacts and low contact resistance for reliable low-level switching.

The HFD23 and HFD41 are both Hongfa signal relays but with different specifications and applications: HFD23 is an ultra-miniature relay (10.0x6.5x5.65mm) with 1A contact rating, ideal for high-density PCB applications

HFD41 is a standard miniature relay (20.0x10.0x11.0mm) with 2A contact rating, suitable for higher current signal switching. Key differences: Dimensions - HFD23: 10.0x6.5mm, HFD41: 20.0x10.0mm

Contact Rating - HFD23: 1A, HFD41: 2A

Contact Configuration - HFD23: SPST or SPDT, HFD41: DPDT standard

Coil Power - HFD23: 100-140mW, HFD41: 200mW

Contact Material - both use precious metal contacts

Applications - HFD23 for ultra-compact designs, HFD41 for general signal switching

Mounting - both are PCB mount. For telecommunications line cards with high relay count, HFD23 enables maximum density. For test equipment requiring DPDT switching, HFD41 provides the right configuration. Both series offer excellent signal integrity with low contact resistance and stable characteristics.

Choose HFD23 for ultra-miniature 1A applications, HFD41 for 2A DPDT signal switching.

Hongfa signal relays feature precious metal contacts with contact resistance of 50-100mΩ. This low resistance ensures minimal signal attenuation and makes them suitable for sensitive measurement and telecommunications applications.

Select signal relays with precious metal contacts for low contact resistance.

Hongfa HFD23 signal relays measure just 10.0 x 6.5 x 5.65mm, making them among the smallest available. This ultra-miniature size enables high-density PCB layouts for telecommunications and portable equipment.

Use HFD23 series for ultra-compact, high-density applications.

Hongfa signal relays are available with coil voltages from 1.5VDC to 24VDC. The HFD27 series is optimized for low voltage operation (1.5-5V), while HFD23 covers standard voltages (3-24V).

Select coil voltage to match your control circuit requirements.