What a robot asks of a switch
A robotic system mixes precision analog sensing, fast digital signaling and power actuation in one frame, and its switching elements have to cover all three without becoming the weak point. Reed relays show up here for a specific set of properties: stability across a long life of more than 109 signal-level operations, the ability to switch AC or DC across a wide span of signal levels, and galvanic isolation between the control and load sides.
Switching the weakest signals in the machine
Tactile grippers, force-torque cells, temperature probes and encoders all output microvolt or picoamp-level signals that have to reach the conditioning electronics without added offset. A sealed reed contact switches these channels with a low, static contact resistance that does not climb as the part ages, because the contact never sees open air to oxidize it. That stability matters in a sensor mux: a contact whose resistance drifts over hundreds of millions of cycles becomes a slow gain error that is hard to distinguish from a real sensor change.
Higher-frequency paths
Robots also carry vision interfaces, fast serial buses and RF links. In an HF path a reed relay provides low insertion loss and useful isolation above 1 GHz, so an antenna, camera or bus segment can be mechanically selected without materially reducing bandwidth.
Series used in industrial robotics
The DIL, PB, MSIP, SIP, HVMR and HVFR families cover the roles found in a robot: standard dual-in-line footprints, compact packages for dense boards, high-voltage actuation and high-insulation measurement channels. Drawing them from one compatible family simplifies qualification across the control and sensing electronics.
Representative specifications
- Contact resistance below 150 mΩ
- Insulation resistance, contact-to-contact: above 109 Ω
- Insulation resistance, contact-to-coil: above 1010 Ω
- Operate time including bounce: below 0.5 ms
- Release time: below 0.5 ms
- Life at 10 VDC / 10 mA: above 107 cycles, toward 109 operations at signal level
Concrete roles inside the system
- Sensor multiplexing — routing multiple weak analog channels into shared conditioning electronics without added offset or noise.
- Self-test and calibration — switching known references into the sensing chain so the robot can verify measurement accuracy between tasks.
- Reconfiguration and redundancy — rerouting a channel to keep running after a fault.
- HF path selection — choosing between antennas, cameras or bus segments above 1 GHz with minimal insertion loss.
- Load control — switching AC and DC actuator loads while keeping control and power domains isolated.
Why it matters for uptime
A robot is judged on uptime, and every switch in its mux, self-test and power-routing paths is a candidate failure point. Sub-millisecond switching keeps reconfiguration sequences short; the sealed contact’s long, wear-light life carries the part past normal service intervals; and stable contact resistance keeps weak sensor readings consistent as the machine ages. Those are the reasons reed relays keep appearing in robotic control hardware even though they are rarely visible in the system block diagram.
About SHR AUTOSENSOR
SHR AUTOSENSOR TECH LIMITED (SHR AUTOSENSOR) manufactures high-voltage reed relays, mercury wetted relays and high-voltage DC contactors. Contact: [email protected] | +86 13761571029 | www.reed-relay.com