Urban attractions and installations
Bell automation
We automate church bells with linear motors that reproduce the motion of a hand-rung bell. The complete system comprises the electrical installation, the electromagnetic hammer, the linear motors, the control panel and the programming control clock with GPS antenna — for bells up to 1,500 kg.
Overview
A bell driven by a linear motor reproduces the natural motion of a hand-rung bell: thanks to the alternating movement of the armature, the ringing speed and timing match those of manual pulling, while the swing angle is controlled and can be adjusted to a resolution of 5 degrees. The constant pulling force removes the harsh movements typical of rotary motors. The linear motors are genuine three-phase induction machines and are used for bells over 150 kg.
Components
- Electrical installation
- Electromagnetic hammer
- Linear motors (LIN 1 or LIN 2)
- Electrical control panel
- Programming control clock with GPS antenna
Installation requires no major work in the belfry: chain wheels, chains and locking springs are eliminated, no large housings, bulky panels or motor stands are needed, and the clapper does not have to be tied or braked. The motor stands on its own feet on the floor beneath the bell and is fitted with a pulling rope; it can be attached to the existing swing assembly's wheel or pull arm without modifying it. The control unit is an embedded microprocessor system with sensors integrated into the motor and dedicated software; power switching is semiconductor-based, with no electromechanical switches (relays). Control parameters are determined automatically, installation takes at most 5 minutes, and configuration is done through a standard ANSI/VT100 terminal.
Advantages
- Service life of at least 15 years, with no periodic adjustment
- GPS-synchronised control clock, accurate to within ± 1 second per 100 years
- Automatic switch between summer and winter time
- Automatic restart and return to the exact time after a power cut
- For bells over 1,500 kg, several motors can be coupled together with a sleeve
Specifications
- Max. bell load — LIN 1
- bells up to 500 kg
- Max. bell load — LIN 2
- bells up to 1,500 kg
- Pulling force — LIN 1
- 200–300 N
- Pulling force — LIN 2
- 500–800 N
- Slip speed
- 3 m/s
- Power supply — LIN 1
- 3×400 V, max. 5 A
- Power supply — LIN 2
- 3×400 V, max. 10 A
- Duty cycle
- 25%
- Own weight — LIN 1
- 5 kg
- Own weight — LIN 2
- 10 kg
- Swing-angle resolution
- 5°
- Installation time
- max. 5 minutes
- Service life
- at least 15 years
Types & options
LIN 1 linear motor
For bells up to 500 kg; 200–300 N pulling force; 5 kg own weight.
LIN 2 linear motor
For bells up to 1,500 kg; 500–800 N pulling force; 10 kg own weight.
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