Do you want to save money on energy bills? Then contact Ronfell on +44 (0) 1257 795186

4B. Stairwell with acoustic detector and dimmable HF operating devices, ‘Dynamic lighting Control’

Svenskt patent nr. 9201493-5, English patent no. 0659329

The premises

The stairwell is a closed area, access to which is through a number of doors. Acoustic technology is thus ideal in this situation, as it is the only technology that allows activation before entry into the area.

Light sources

The fittings in this stairwell have dimmable HF operating devices with analogue control (1 – 10 V).

Control system

With new buildings or renovations when there is the option of selecting operating devices in the fittings, bearing in mind experiences in the field and the current state of technology it is now a serious error to use installations without Dynamic Lighting Control. The technology can be used in both acoustic control and control with IR detectors.

NB: With acoustic detection it is a prerequisite for the stairwell to be closed, i.e. for there to be doors that are normally closed to all other areas.


When entering the stairwell the lighting is activated at the normal level set on the ‘High’ potentiometer in the NV-2 level selector, e.g. about 80 per cent. The lighting remains activated at 80 per cent throughout the period of presence. When the presence ceases and after the delay set for Relay Output A, the lighting dims to basic light level, which is set at about 2 per cent on the ‘Low’ potentiometer in the NV-2 to stop it going completely dark in the stairwell.

Positioning of detectors

The positioning of detectors and microphones is shown in the example above. For more detailed directions, please see the manual for the AD500/600.

If there is no presence in the stairwell for a prolonged period, i.e. the 1 – 2 hours set as the delay for Relay Output B, the lighting is switched off completely for a rest period to avoid no-load losses. The maximum delay that can be set for Relay Output B is 200 minutes.
See also diagram below!

NV-2T level selector is also available with DSI control (NV-2T DSI).
This is a wiring diagram for Dynamic Lighting Control with acoustic detection. Connection of the microphones, that are connected in parallel, is possible with EKKX 1 x 4 x 0.25 mm2.

The most important advantages attained using Dynamic Control are as follows:
Evenly distributed basic light without extra fittings, operating at a level of 100 per cent.
The possibility of saving 20 – 25 per cent during operation.
Lower working temperature in the fittings, resulting in a lower life.
Fewer activations and less power supplied, reducing wear on the fluorescent powder and resulting in a longer life of the light sources.
The possibility of avoiding adherence to the light-source manufacturers’ recommendations regarding burning times, thus drastically reducing the operating times and increasing the saving.
The acoustic detector is available in 2 models: the AD-500 and the AD-600. The AD-500 features metal encapsulation and built-in microphone. The AD-600 has plastic encapsulation for mounting on a DIN bar.
An optional light sensor is available that prevents lighting from being switched on when there is adequate daylight.
See the relevant manual for adjustment and programming.

Acoustic detector

The acoustic detector detects sound in two frequency ranges: inaudible low-frequency infrasound (0 – 3 Hz) and audible high-frequency sound (6 – 8 kHz). These frequency ranges are separated by a range in which the detector is deaf. See the audiogram below.

Information for current budget

Product Maximum current consumption (mA)
Microphone AD-260 22


Product Order No.
Acoustic detector AD-600 13091
Microphone AD-260U 2 ea. 13106
Level selector NV-2(1-10v) 13168
Microphone AD-260P 2 ea. 13105
Level selector NV-2 DSI 13169A
Light sensor LS-10 (daylight override) 13100
Dynamic lighting control in stairwells

The yellow area represents the energy consumption with conventional lighting control in accordance with the light-source manufacturer’s recommended burn times.
The green area represents the energy consumption with dynamic lighting control installed.
The yellow area represents an unnecessary energy cost!