I am developing a heating application where temperature need to be constant. I am planning to set the temperature @ 200 degree C. when my sensor find the temperature exceeding the set temperature how can i reduce the temperature of the heating element. I currently plan to cut the supply to heating element but is there any other method which i can reduce the temperature.
\$\begingroup\$
\$\endgroup\$
3
-
1\$\begingroup\$ Can you regulate the power of the heating element? \$\endgroup\$– Eugene Sh.Commented Mar 23, 2015 at 16:43
-
1\$\begingroup\$ What kind of heating element is this and how do you control it? A lot of them are fine with bang bang pwming. \$\endgroup\$– PlasmaHHCommented Mar 23, 2015 at 16:55
-
\$\begingroup\$ I am hopping to regulate the power of heating element with a relay switch...the element I use is heat seal machine heating element. It's an ceramic type heater element \$\endgroup\$– romy mathewCommented Mar 23, 2015 at 18:11
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
2
Practically you have two main choices involving i) on/off control; ii) average control.
i) Hysteretic control turns the heater on at a lower limit and turns it off at an upper limit. (i.e. on/off).
ii) Drive the heater with a fast switching PWM signal (via Switches and a switch-driver) so that the average value of the temperature is your desired setpoint value. This usually involves feedback and a controller such as a PID.
-
\$\begingroup\$ Does power off and on bring down the life of the Heating element ...? \$\endgroup\$ Commented Mar 24, 2015 at 10:53
-
\$\begingroup\$ Most heating wires have a positive tempco so they draw more current when cold so current surges may (in theory) reduce lifetime. In your case the element should stay at a fairly constant temperature so On/Off pulsing shouldn't be a problem. \$\endgroup\$ Commented Mar 24, 2015 at 11:10