What is the hottest part of this controller?

[its_me_jason]

Does Anyone know what the hottest part of the controller is?

I bought a digital LCD thermometer like this!

right now I have it placed inside the controller next to this black box and I'm getting 30C readings

here is a better photo of my I zip 24v controller for my 450W motor.

Where should I position the thermometer sensor next to get better readings?

 

[spinningmagnets]

I'm going to guess that the FET heat sink is the hottest part, and it looks like the FETs are up between the aluminum housing and the two tall brown cylindrical capacitors (they say 470uF 63V) near the bottom of the second pic. I'm guessing the housing is aluminum and it's used as the heat sink, so...the inside of the housing next to the row of FETs.

I don't know why this controller looks like it has 7 FETs, but the hot part in this pic is the top edge with the 7 square things being held onto it by one screw each.

 

[dnmun]

the black box is a relay, no heat there.

 

[its_me_jason]

thanks guys!