I was researching how to control a Solarscreen with A IKEA Zigbee device. As IKEA uses Zigbee for their home automation. I checked the working of the IKEA 503.561.87 (TRÅDFRI) LED driver. It seems that it uses Pulse Width Modulation(PWM) to control the brightness of the LED or LED-string.
I also use the Phoscon Zigbee USB dongle Conbee II and a Raspberry Pi with their very well documented API and user interface/home automation software installed to control my Zigbee home devices. You do not need them for you project, but If you want to program your own scenes it is very useful.
First of all I found that the PWM was at 1 kHz frequency and output of 0-24V DC. The results of the settings on the Zigbee device are shown here:
Then I was searching for a ventilator for our bathroom. And I found a ventilator from Ruck that uses PWM input for the speed control (Ruck EM 100L EC 02):
In the technical documentation of this Ventilator the input for the PWM was 1kHz and max 10V. Well with some calculation I used 1k and 1k5 resistor to make a 24V to 10V step down circuit and soldered it to the output:
The last step was the testing, and make it production save and ready:
The ventilator is now controlled by a IKEA TRÅDFRI Remote control (5 button Zigbee device). The control is done by Java code software running on a Raspberry Pi and using the Webhooks of the Phoscon API to achieve direct control.
