Hi Guys,
I have an AF45E saw where the speed control is not working. When I power up, it speeds up to high speed and no response for speed control the red LED is continously lights what means overload. The green LED is just blinks up for a short time and goes off permanently.
The speed feedback magnetic ring seems works fine. It generates sine wave, checked by oscilloscope.
I assume that there is a defect with the temperature sensor. On room temperature the resistance is around 170ohm. If i heat, then drops down to 160, then increases again. Strange... I have enclosed the image of the temperature sensor. Seems like a resistor, not a semiconductor, but no idea...
I assume that Festo uses this sensor for most of their saw product with speed control. Could you please measure the resistance for me on your device and check the value with multimeter in both polarity?
If I put a potentiometer instead of the sensor, I can find a value where I am able to modify the speed with the dial, but the red LED always lights.
Have you ever seen beaviour like this?
Thanks in advance for your reply.
Attila
I have an AF45E saw where the speed control is not working. When I power up, it speeds up to high speed and no response for speed control the red LED is continously lights what means overload. The green LED is just blinks up for a short time and goes off permanently.
The speed feedback magnetic ring seems works fine. It generates sine wave, checked by oscilloscope.
I assume that there is a defect with the temperature sensor. On room temperature the resistance is around 170ohm. If i heat, then drops down to 160, then increases again. Strange... I have enclosed the image of the temperature sensor. Seems like a resistor, not a semiconductor, but no idea...
I assume that Festo uses this sensor for most of their saw product with speed control. Could you please measure the resistance for me on your device and check the value with multimeter in both polarity?
If I put a potentiometer instead of the sensor, I can find a value where I am able to modify the speed with the dial, but the red LED always lights.
Have you ever seen beaviour like this?
Thanks in advance for your reply.
Attila
