Hi
I'm trying to build a circuit which will alert me when the temperature rises above -4 deg.(in the fridge...of course).
I built the circuit, as the image attached, just that I used LM358 instead of LM311.
at first I used the IRF530, but it didn't work, I don't know why.
so I used a c945 instead, and it works. just that when I measure volts on the 33Kohm (even without the buzzer,if it matters). I get about 2.3V instead of 4.5V as I thought I should.
Can anyone tell me why is that? and why doest the IRF530 didn't work?
Thank you
I'm trying to build a circuit which will alert me when the temperature rises above -4 deg.(in the fridge...of course).
I built the circuit, as the image attached, just that I used LM358 instead of LM311.
at first I used the IRF530, but it didn't work, I don't know why.
so I used a c945 instead, and it works. just that when I measure volts on the 33Kohm (even without the buzzer,if it matters). I get about 2.3V instead of 4.5V as I thought I should.
Can anyone tell me why is that? and why doest the IRF530 didn't work?
Thank you