Regarding Pin details of MQ-7 Sensor

[Vignesh_V]

Hi friends,

I have need to know about pin details of one sensor. I am using MQ-7 sensor interface with Stm32  for my project purpose and I design one custom made PCB design. So ,I buy MQ-7 sensor separately that sensor doesn't indicate any start point of pin like 6 pins are there in that sensor. But the manufacturer does not indicate which pin is first pin. I try to find browser it shows separate that 6 pins in 3 category like A,B,H. But I don't know which is A and B and H.So, I need your help.Thank you for value time and Response.I have attached MQ-7 sensor picture in below.

 

[Peter BENSCH]

Well, that's a question that you would actually have to clarify with the manufacturer. In the absence of a data sheet, I can only judge from your schematics and according to that, the sensor appears to be symmetrical. The two outer pins of a group of three are to be connected together and either connected to VCC or provide the output signal. As with MOX sensors, the two centre pins obviously only have current flowing through them (heating), so the direction of the current should not matter. In this respect, you should be able to use the sensor in both directions.

Hope that helps?

Good luck!
/Peter