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Self-powered Emergency Bell System
An emergency bell that sends a signal from the force of a press, with no battery or wiring
The self-powered emergency bell uses no batteries and operates only when the user presses it. With no wiring needed, it can be mounted anywhere at any height, and the Single-window Monitor, beacon light and PC immediately show which emergency bell was pressed.
Under the "Act on Public Restrooms", since July 21, 2023, emergency bells have been mandatory in all public restrooms used by citizens, including open and mobile restrooms.
- PowerSelf-powered (no battery)
- Dust · water protectionIP57
- Transmission rangeapprox. 100 m (open field)
- Durability100,000-cycle operation test
- RegistrationUp to 224 units per Single-window Monitor
- Range extension1 km or more with relays · repeaters
01How it works
- Emergency · bell pressed
The pressing force generates electricity and sends a unique ID signal.
- Number shown on Single-window Monitor
The number and an alarm sound indicate which emergency bell was pressed.
- Beacon light · PC monitoring
The on-site beacon light goes off, and the alert is checked at the same time on a PC connected via RS485.
02Features
With no batteries or wiring, there is no wall work or battery replacement.
No spent batteries are produced.
Installed indoors or outdoors — restrooms, parking lots and outdoor areas.
Passed 100,000-cycle operation · RF signal tests.
Add relays (+150 m) to extend coverage to 1 km or more.
Integrates with third-party emergency call units via the RF communication module, and controls ON/OFF of other devices via the DC receiver.
03System configuration
Self-powered Emergency Bell (round)MWST-110
RelayMWSRT-800 · Optional
Single-window Monitor (receiver)MWSM1-300
PC monitoringSensor location · detection history
Beacon lightOn-site alarm
Emergency call unitThird-party equipment integrationRanges are based on open field with no obstacles. Each added repeater extends the range by approx. 1 km.
Up to 224 emergency bells can be registered per Single-window Monitor. With a Signal Monitor, up to 999 can be registered.
04Specifications
Self-powered Emergency Bell (round)
Model MWST-110
| Size | Φ63 × H25 mm |
|---|---|
| Weight | 38 g |
| Frequency | 920.700 MHz (FSK) |
| Antenna | Internal antenna |
| Transmission range | approx. 100 m (open field) |
| Power | Self-powered (no battery) |
| Dust · water protection | IP57 |
| Durability | 100,000 operations |
Single-window Monitor (receiver)
Model MWSM1-300
| Size | W154 × D108 × H33 mm |
|---|---|
| Weight | 280 g |
| Frequency | 920.700 MHz (FSK) |
| Antenna | External antenna |
| Reception range | approx. 150 m (open field) |
| ID registration | max. 224 |
| Signal storage | max. 10 |
| Display | FND 2-digit, Signal storage LED |
| Power | DC 12 V 1 A adapter |
Relay
Model MWSRT-800
| Size | W115 × D115 × H28 mm |
|---|---|
| Weight | 160 g |
| Frequency | 920.700 MHz (FSK) |
| Antenna | External antenna |
| Tx/Rx range | approx. 150 m (open field) |
| Range extension | +approx. 150 m (open field) |
| Max. connections | max. 10 |
| Display | FND 3-digit, Power · Rx · Tx LED |
| Power | DC 12 V 1 A adapter |
RF communication module
Model MRRC-500
| Size | W40 × D25 × H7.5 mm |
|---|---|
| Weight | 5 g |
| Frequency | 920.700 MHz (FSK) |
| Antenna | Chip antenna |
| Reception range | approx. 100 m (open field) |
| Output | RS232 / TTL 3.3 V |
| Display | Red LED (operation indicator) |
| Power | DC 3.3 – 6 V |
DC receiver
Model MWSRD-500
| Size | W43 × D30 × H7 mm |
|---|---|
| Weight | 5 g |
| Frequency | 920.700 MHz (FSK) |
| Antenna | Chip antenna |
| Reception range | approx. 100 m (open field) |
| ID registration | max. 10 |
| Display | Red LED (operation indicator) |
| External terminals | VCC, GND, PWM OUTPUT |
| Power | DC 3.3 – 6 V |
Beacon light
Model DL-125B
| Size | Φ125 × H155 mm |
|---|---|
| Weight | 380 g |
| Display | Rotating LED light · siren |
| Power | DC 12 V 2 A adapter |
Specifications are subject to change without notice for performance improvement.
05Applications
Places vulnerable to emergencies, such as women's restrooms and accessible restrooms
Installed at any height so even bedridden patients can press it easily
Installed in factories without adding wiring to existing buildings
Sends a signal to the security system in an emergency, connecting to the control room
Installation sites
Field installation photos16
Registered on the Public Procurement Service's Venture Nara in 2020, and installed in accessible restrooms at elementary, middle and high schools, public restrooms, parking lots, hospitals, courts and more.
Applicable platforms
A system that monitors alarm situations from multiple emergency bells together, using wire-free self-powered emergency bells, on-site beacon lights and a control room monitor
Emergency Call Device PlatformA system in which an RF communication module receives emergency bell and sensor signals as RS232 / TTL signals and integrates them with emergency call units
Wireless Call PlatformA system in which the Single-window Monitor sends wireless call bell signals to PLC equipment via RS485 for control
Device Control PlatformA system that stops devices and motors connected to AC 220 V and cuts their power at the press of a button in a dangerous situation
06Certifications · patents
KC Conformity Registration — Transmitter (emergency bell · wireless switch)R-R-M1p-MWST-100 · 2019-09-26
KC Conformity Registration — Single-window MonitorR-R-M1p-MWSM1-300 · 2019-09-26
KC Conformity Registration — RelayR-R-M1p-MWSRT-800 · 2019-09-26
KC Conformity Registration — RF Communication Module (RF receiver)R-R-M1p-MRRC-500 · 2020-02-05
KC Conformity Registration — DC ReceiverR-R-M1p-MWSRD-500 · 2019-09-26
FCC — Self-powered Emergency BellFCC ID 2BTDM-MWST-110 · 2026-05-28
Japan MIC — Wireless Switch
Wireless self-powered bell (round)Registered (Korea)
Wireless self-powered bell (hinge type)Registered (Korea)
07Materials · videos
08FAQ
QDoes it really need no batteries?
Yes. The force of pressing the emergency bell moves a magnet inside past a coil to generate electricity, which is used to send the signal. There is no need to worry about battery replacement or discharge.
QDo the receiver (Single-window Monitor) and relay also need no power?
The emergency bell needs no power, but the Single-window Monitor, relay and beacon light are connected to a constant power supply via a DC 12 V adapter.
QCan it connect to the emergency call units we already use?
The RF communication module (MRRC-500) converts the emergency bell signal into an RS232 / TTL 3.3 V signal and passes it to third-party emergency call units.
CONTACT MPIA
Self-powered Emergency Bell System
An emergency bell that sends a signal from the force of a press, with no battery or wiring