Induction Proximity sensor issue

[naeemidrees]

Hi,

I am using induction proximity sensor in my circuit. Some time specially in winter sensor do malfunction. Means sensor randomly trigged. I am use NPN type sensor.

Please help me.

 

[bertus]

Hello,

Do you have a datasheet of the sensor to post?
That way we can see the properties of the sensor.

Bertus

 

[Minder]

What would the typical 'winter' temperature experienced by the sensor?
M.

 

[naeemidrees]

Data sheet Attached

 

[naeemidrees]

In my country min temperature will be 5C but with dry.

 

[naeemidrees]

I am using Atmega32 uc.

 

[bertus]

Specifications (cont.)
Ambient temperature
Operating : -25° to +70°C (-13° to +158°F)
Storage : -30° to +80°C (-22° to +176°F)

What is the temperature in winter?

Do you have a complete schematic to share?

Bertus

 

[Minder]

What form does the 'flag' take that triggers the Prox?
What is the nature of the input, any opto etc?
M.

 

[naeemidrees]

I am using opto PC817

 

[naeemidrees]

 

[bertus]

Hello,

I assume you are using a single 24 Volts power supply.
The schematic suggests a dual 24 volts power supply, that would give 48 Volts on the sensor.
The current through the led of the 817 will be about (24 -1.2) V / 5600 Ohms = 4 mA.
Perhaps lowering the resistor value may give a more stable result.
Try a resistor of 2200 Ohms in stead of the 5600 Ohms.
Wich version of the PC817 are you using?
There are 4 different sensitivity ranges.

Bertus

 

[naeemidrees]

I am using PC817 - 1 Channel type.
This circuit drive two 24v solenoid. Mean noise environment.

 

[naeemidrees]

I am waiting of ur reply.

 

[bertus]

Hello,

As I asked before, wich version of the PC817 are you using:



Also did you try a different resistor for the IR led of the PC817?
Also what is the value of R5 in your schematic (the collector resistor of the opto)?

Bertus