temperature control help

[temperature help]

hi guys
i have a project to design a solution that will maintain the temp of a living space with a volume of 400m3 between 25-30 degrees centigrade.

i can use the following components.

LM35 Temperature sensor
LM358 operational amplifier
3x LM311 Comparators
74LS32 quad or gate
74LS04 hex NOT gate
2X12 volt relay

any help on a circuit design would be really appreciated.
THANKS

 

[Boncuk]

You didn't clearly describe the project.

A constant temperature of 25 to 30 deg/C means nothing but constant cooling in Thailand, at higher latitudes it certainly means heating.

What are you using for cooling/heating?

What is the required accuracy of the control device?

Boncuk

 

[temperature help]

when the temperature rises above 30 we need a fan to kick in and when under 25 a heater. any ideas on a circuit using the components listed.

thanks

 

[ericgibbs]

when the temperature rises above 30 we need a fan to kick in and when under 25 a heater. any ideas on a circuit using the components listed.

thanks

hi,
It should be possible to make a tempr controller using the parts you have listed.

You have not given details of the relay contacts or how much heating power/current you want to control.

 

[blueroomelectronics]

Can you use different parts?

 

[Boncuk]

One part of your listed will do the job besides two low power transistors (to activate the relays).

Use the LM385 and make it a window comparator. Above window means temperature >30deg/C -> activate cooling fan, below window <25deg/C means heating.

Boncuk