DD-L25/L45 Series Micro U-Slot Photoelectric Switch
A homing reference you can trust to a hundredth of a millimetre — in a body small enough to hide inside the module.
- Repeatability within 0.01 mm, hysteresis ≤ 0.025 mm
- Detects miniature flags down to 2 × 0.8 mm
- 10 compact housings: K/L/U/F/R shapes × 25/45 mm sizes
- NPN or PNP with selectable NO/NC — 20 part numbers
- IP65 sealed, DC5–24V, under 15 mA, 1 m pre-wired cable
When the Slot Sensor Is Part of the Position Loop
On a conveyor, a slot sensor only needs to say "something passed". On a linear stage, it becomes part of the machine's coordinate system: every homing cycle re-zeros the axis at the sensor's switching point, and any wander in that point becomes position error in every subsequent move. The DD-L25/L45 is specified for exactly that duty — repeatability within 0.01 mm and hysteresis of 0.025 mm or less, published figures rather than hopeful assumptions.
The mechanical range is equally deliberate: two body sizes (25 / 45 mm) in five mounting shapes (K/L/U/F/R) so the sensor conforms to the module instead of the module conforming to the sensor, plus an IP65 rating that tolerates dust and water jets — not a given in this size class.
Published precision at the switching point: a ±0.01 mm repeatable ON position with no more than 0.025 mm between ON and OFF.
Model Selection Table — 20 Part Numbers
| Models | Detection Method / Body | Detection Groove / Object | Output |
|---|---|---|---|
| DD-K25N / L25N / U25N / F25N / R25N | Through-beam micro U-slot, 25 mm body, shapes K/L/U/F/R | 5 mm groove; min. object 2×0.8 mm | NPN, selectable NO/NC |
| DD-K45N / L45N / U45N / F45N / R45N | Through-beam micro U-slot, 45 mm body, shapes K/L/U/F/R | 5 mm groove; min. object 2×0.8 mm | NPN, selectable NO/NC |
| DD-K25P / L25P / U25P / F25P / R25P | Through-beam micro U-slot, 25 mm body, shapes K/L/U/F/R | 5 mm groove; min. object 2×0.8 mm | PNP, selectable NO/NC |
| DD-K45P / L45P / U45P / F45P / R45P | Through-beam micro U-slot, 45 mm body, shapes K/L/U/F/R | 5 mm groove; min. object 2×0.8 mm | PNP, selectable NO/NC |
Common ratings: repeatability within 0.01 mm, hysteresis ≤ 0.025 mm, IP65, DC5–24V ±10% at under 15 mA, pre-wired 1 m cable. Additional housing shapes seen in catalogue photos (e.g. Y45, T45) — confirm availability with the factory. Response time and light-source wavelength are not published for this series.
Note: general-purpose detection sensors, not IEC 61496-certified safety components — do not use them alone for personnel protection.
Typical Applications
Home & Limit Positions on Precision Stages
0.01 mm repeatability means the sensor adds essentially no position error of its own to a linear stage or electric slide reference.
Semiconductor & 3C Assembly Modules
Miniature flags down to 2×0.8 mm are caught inside cramped module interiors thanks to the micro body and 5 mm groove.
Miniature Valve & Actuator Feedback
Mount beside the actuator arm or cam for a crisp in-position signal with 0.025 mm hysteresis.
Lab Automation & Analyzer Mechanisms
IP65 sealing and under-15 mA draw suit dense, long-running instrument interiors with occasional splash exposure.
Frequently Asked Questions
How precise is the switching point, really?
Repeatability is within 0.01 mm — the output flips at virtually the same flag position on every pass — and hysteresis (the gap between switch-on and switch-off positions) is 0.025 mm or less. Those are the two figures that matter when a slot sensor serves as a homing reference on a precision axis.
How is the model number built?
DD-[shape][size][output]: shape K, L, U, F or R; body size 25 or 45 mm; output N (NPN) or P (PNP). Example: DD-K25N = K-shape, 25 mm body, NPN. Five shapes × two sizes × two outputs = 20 part numbers.
Can I switch NO/NC without a different part number?
Yes. Every model supports selectable NO/NC (Light-ON/Dark-ON) operation, so one NPN and one PNP part number cover all four output-logic combinations for spare-parts stocking.
What is the smallest object it can detect?
2 × 0.8 mm through the 5 mm groove — small enough for the miniature flags used in semiconductor handlers and compact automation modules. Objects finer than that call for a fiber-optic solution.
Is it sealed well enough for industrial environments?
Yes — the series carries an IP65 rating (dust-tight, protected against water jets), unusual for micro slot sensors, which are often IP50-class. It still should not be submerged or pressure-washed.
What are the electrical basics?
DC5–24V ±10% supply, current consumption under 15 mA, pre-wired with a 1 m cable as standard. Response time and light-source wavelength are not published for this series — contact the factory if these are hard requirements.
The catalogue photo shows shapes like DD-Y45 and DD-T45 — can I order those?
The confirmed ordering matrix covers K/L/U/F/R in both sizes. Y45 and T45 housings appear in catalogue photography; contact the factory to confirm current availability and specifications before specifying them.
What about samples, MOQ and export terms?
As the manufacturer we support sample evaluation and small trial orders, with OEM marking and consolidated export shipment available. Send the shape/size/output split you need for a quotation; certification documents on request.