How Can I Design a Temperature Control Unit Using Light?

[tics]

hi everybody i need to design a temperature control unit that works in acordance to light, ie: when there is minimal light then the heating element must come on, and when there is lots of light the heating element must go off...


these are the following specs of the design:
-555 timer must be used
-heating element is a 12VDC lamp (60W)
-max heat at 3cm away must 40 degrees celsius
-12VDC supply
-controlled voltage (dc chopped voltage)
-LDR
-LED's for status indications
-when the max temp is reached the circuit must switch off...

any advice and design suggestions are more than welcome
thanks a lot
Tics

 

[berkeman]

hi everybody i need to design a temperature control unit that works in acordance to light, ie: when there is minimal light then the heating element must come on, and when there is lots of light the heating element must go off...


these are the following specs of the design:
-555 timer must be used
-heating element is a 12VDC lamp (60W)
-max heat at 3cm away must 40 degrees celsius
-12VDC supply
-controlled voltage (dc chopped voltage)
-LDR
-LED's for status indications
-when the max temp is reached the circuit must switch off...

any advice and design suggestions are more than welcome
thanks a lot
Tics

Per the PF rules, we can't do your project for you. Please post your thoughts on how to proceed with the circuit design...