Microwave Radar Sensor Switches — 5.8 GHz, ceiling and inline
Doppler radar detects movement from reflected radio waves rather than body-heat contrast. That makes radar useful where PIR performance is affected by temperature or where the sensor must be concealed; through-panel behaviour and nuisance triggering depend on the selected model, sensitivity, surrounding material and placement.
TDL-1915 5.8 GHz Ceiling Sensor Switch
A surface-mounted ceiling puck for corridors, stairwells, bathrooms and back-of-house areas, switching the luminaire circuit directly. What makes it worth specifying over a fixed-parameter switch is that all three commissioning variables — how far it reaches, how long it holds, and how dark it has to be before it will act — are set on the unit itself, so one part number covers a lift lobby, a mid-corridor run and a service stair.
| Frequency | 5.8 GHz Doppler microwave |
|---|---|
| Operating voltage | AC 85–250 V |
| Detection range | 2–16 m, adjustable |
| Delay / hold time | 8 seconds – 12 minutes, adjustable |
| Daylight threshold | 2–2000 lux, adjustable |
| Standby power | 70 mW |
| Transmitting power | < 10 mW |
| Dimensions | 94 × 94 × 45 mm |
| Current rating | 10 A (2026 catalogue) |
| Manufacturer load limits | LED ≤150 W · incandescent ≤800 W · exhaust fan ≤200 W |
| Radio certification | None held for this model; testing for your market must be scoped before import |
| Adjustment | Three rotary trimmers on the unit |
Tell us the LED driver or exhaust-fan type and its starting current; other motors, transformers and capacitive loads need a separate suitability check.
Ask about TDL-1915
Through-wall detection
The factory's own range diagram shows the detection field it wants you to plan around — roughly an 8 m radius hemisphere from the ceiling down to the floor — and then, separately, that the field extends approximately 1–2 m through a wall, varying with the sensitivity setting.
Through-wall detection is the reason radar can be concealed above a plasterboard soffit or behind a diffuser and still work, which no PIR switch can do. It is equally the reason a unit commissioned at full sensitivity in a small bathroom can be triggered by someone walking past in the corridor outside, and the room light will appear to switch itself on for nobody.
What to do about it: specify the sensitivity setting per room type at order stage, not per project, and have the installer prove the boundary by walking the far side of every wall before signing the room off. If the layout puts a busy circulation route directly behind a small enclosed room, use PIR there and keep radar for the open runs.
Choosing between the two
- Radar suits warm corridors, stairwells and plant areas; sensors that must be hidden inside or behind a fitting; and spaces where PIR range has visibly collapsed in summer.
- PIR suits small enclosed rooms with traffic on the other side of a partition, and any space where you need detection to stop hard at the wall line.
- Neither reliably holds a light on for someone completely still. For that you need presence sensing: TUODI's 2026 catalogue lists a 24 GHz presence range (see the switch hub), not yet radio-certified. Ask early if your project needs it.
- The full comparison, including hand-wave, is in the PIR vs radar vs hand-wave guide.
Comparing 5.8 GHz switches
Housing shape and headline range do not tell you how a radar switch behaves beside another unit, with a fan running, behind a panel or on a real LED driver. Convert every construction or “better quality” statement into a repeatable sample or production check:
Sample and production checks for radar switches
| Area | Ask the supplier to state | Check on the intended build |
|---|---|---|
| Detection field | Range/angle at the target mount height, sensitivity steps and through-panel/wall behaviour. | Walk the room boundary at minimum and maximum settings, including the far side of partitions. |
| Adjacent units | Recommended spacing, channel/algorithm behaviour and maximum layout already tested. | Run several units together and watch for staggered switching, chatter or one unit triggering another. |
| Nuisance triggers | Known response to fans, airflow, machinery, doors, vibration and small incidental motion. | Operate those sources in the real room while logging false-on and false-off events. |
| Output & load | Relay or dry-contact output, actual lamp/driver type, inrush/derating and any protection or snubber provided. | Switch the intended driver/load repeatedly; record heat, relay chatter and state after power loss. |
| Settings | Exact distance, delay, daylight and re-trigger logic for the supplied firmware/revision. | Measure each setting across several samples rather than accepting the printed knob scale alone. |
| Environment & documents | Operating limits, ingress test reports, production checks and the issued model/market documents. | Put test limits, lot sample plan, report format and remedy on the order; a proposed certificate route is not coverage. |
Also in the microwave range
TDL-2076WB
A compact plug-through 5.8 GHz microwave switch for indoor lighting control. Its six sensitivity steps run from 50% to 100%; maximum published coverage is 8 m through 360°. Four delay selections — 3, 15, 30 or 60 seconds — and an on/off light-control setting are selected by DIP switches. Continuous re-triggering keeps the load on while motion continues.
| Operating voltage | 85–277 V AC |
|---|---|
| Load | Incandescent ≤1200 W; CFL / energy-saving or fluorescent ≤600 W; LED ≤150 W |
| Detection | Up to 8 m; 360°; six sensitivity steps from 50% to 100% |
| Delay | 3 / 15 / 30 / 60 s |
| Static current | <0.3 mA |
| Working temperature | −10 to +35 °C |
| Dimensions | 67 × 56 × 31 mm |
| Ingress | IP54 housing marking, factory self-declared, not third-party tested; indoor use only |
TDL-7158WB-T
A 10 GHz hand-wave toggle rather than an occupancy switch: it installs inline on a T5/T8 batten cord and switches on a deliberate hand movement under 30 cm, so it works with wet or greasy hands. See hand-wave switches.
Notes
TDL-1915 load: the catalogue's 10 A current rating does not establish suitability for every appliance. Confirm the LED driver or exhaust-fan type, starting current and any required derating in writing on the quotation, and the exact load and starting current before ordering.
Commissioning: confirm the installation boundary on the sample before specifying radar. If unwanted switching occurs, reduce the distance setting to suit the room and repeat the boundary test before accepting the installation.
Certification: no FCC ID is currently available for the TDL-1915. A lab quote or timeline is not a certificate; treat only an issued document naming the exact model as coverage.
Ingress markings: read every IP number on this page the same way. Without a named test report beside it, it is a manufacturer's marking, not a tested rating.