Relay thermistor circuit?

[jimhellmizer]

i need help with info on Relay thermistor circuit

what the use of the LM324 IC
what are the advantages and disadvantages of LM324 IC in a Relay thermistor circuit { guessed Velleman thermostat kit no MK 138}
and how hysteresis works the circuit?

 

[(*steve*)]

OK, first post the circuit diagram.

Second, tell us what you think the answers *might* be. Where does your thinking lead you?