Rosahl RD4 Electric Micro-Dehumidifier

The RD4 by Rosahl is a compact flat-membrane dehumidifier module for volumes of up to 2 litres at the inside of an enclosure.

Operation Principle

Like all Rosahl dehumidifiers the RD4 is based on a solid-state polymer membrane. When supplied with a 3V DC voltage, moisture on one side is being decomposed into Hydrogen ions and Oxygen, the Hydrogen ions pass the membrane and recombine with air Oxygen to moisture again on the other side and get discharged.

Power Supply

The Rosahl RD4 dehumidifer requires a 3V DC supply voltage and draws in continous operation i.e., when the moisture level in the volume stabilized to a low level, just around 80mW power.
Due to the membrane being intrinsically hygroscopic, it absorbs humidity if no supply voltage is present. This moisture needs to be discharged on startup and leads to a significantly higher inrush-current that the regular operating current. During startup the supply voltage shall still not drop below 2V, otherwise moisture discharge is not possible or significantly delayed. Suitable current supplies are fold-back current limiting sources, which regulate the output current further down than pure constant current sources and hence maintain a certain output voltage. We provide suitable USB-C voltage regulator modules with fold-back current limiting:

• USB-C 5V->3V/500mA voltage regulator module for Rosahl PD/RD/RS dehumidifier

Technical Parameters RD4

Applicable Volume	~2000ccm (2l)
Dehumidifying Performance	84mg/day
Supply Voltage	2.9-3.3VDC
Power Consumption	80mW (20°C/60%rH)
Rated Current	50mA (dep. of rH)
Inrush Current	500mA
Operating Temperature	-10°C - +50°C
Connecting Type	Soldering

 

 

Further Information

• RD4 Product Specification

Scope of Delivery

The Rosahl RD3 dehumidifier comes as single unit with gasket.

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Manufacturer Information
RYOSAI TECHNICA CO., LTD., 8-1-1 Tsukaguchi-Honmachi, Amagasaki-City, Hyogo, 661-0001 Japan, Email: ryosai_sales@ryoyo.co.jp