Windows mobile photovoltaic resonator

Descripton

Solar powered noise generator is designed to masking acoustic signal coming through window. It is suitable to prevent unwanted eavesdropping or making an unauthorised recording various types of spying devices, e.g.:
– Laser microphones, based on interferometric and incident / reflected angle methods
– directional microphones
– stethoscopic microphones
– microwave microphones
– ultrasound doppler microphones

How it works

Noise generated with internal piezzoelectric transducer is transferred into window glass through stiff metal element on the front surface of the device.
Acoustic signal corruption caused by noise makes original audio signal unrecoverable.
Device is powered with small solar panel together with built-in Li-Ion cell. Power consumption of the device is highly optimized, so all season operation with solar cell is possible up to approximatelly 55° latitude, even on window facing opposite to sunny side.
Device is also equipped with protection circuits preventing Li-Ion cell from over and undervoltage and also from overheating.
As a part of the device there is the remote control for switching it on and off.
Device has output for an external piezzoelectric resonator. This allows use only one unit on window with two panes.
In case of extreme low sunlight, device can be optionally charged using standard micro-USB charger.

Technical data

type description: NG-01
device classification: class III, SELV
power supply: solar cell, 5V DC / 1A USB charger
built-in Li-Pol cell: 1 x 3.7 V, 780 mAh
maximum power consumption: 5 VA (ext. charging)
frequency range of noise: 100 Hz to 4 kHz
power of the noise generator: ~ 1.5 mW
recommended maximum window surface: 4m2
capacitive load of the noise output: 10nF max.
operating temperature range: 0 to 45 °C
colour: Anodised alluminium – silver
dimensions: 160 x 70 x 10 mm
intended for use in dry indoor environments only

Mounting and accessories:

Magnetic mounting system – the device is equipped with magnets to snap it on the narrow steel frame, which is sealed to the window. This enables easy window maintenance without risk of damage of the device by cleaning fluids.

No power suply, no cables to the window – the device is designed to be operated only on solar power. Solar panel is large enough to keep device active not
only at direct sunshine, but also on windows illuminated with only diffuse daylight. Fully charged Li-Ion cell is sufficient for about 1-2 months of operation without sunlight.

Pressure tuning screw – the proper pressure between transducer and glass surface is essential to maximize noise transfer into glass sheet. Easy and precise tuning of the pressure for maximum acoustic effect helps to achieve optimal performance even with very low noise power. This is important for long term solar operation.

Optional charger – although device should be energetically self-sufficient all season approximately up to 55° latitude, it is possible to charge it using common 5V micro-USB charger.

Device is equipped with an integrated switch-off timer that is set by the manufacturer for one-hour period. Device is also equipped with the remote control for switching it on and off.