temperature controller response time

[bigboss33]

Hi,

for my university project i had to build a battery powered device to control the temperature of two small metal rods.

I'm using a thermocouple signal which is amplified, then a comparator stage switches the heater on/off at the setpoint temperature.

When i use an independent thermocouple i find it responds much faster than my amplifier. do you think this is due to the thermocouple itself or the amplifier?

I'm using a mcp619 in a difference amplifier configuration.

 

[albert22]

Unless you have slowed down the op amp with capacitors. There is no way that a thermocouple will be faster than an op.
The time that the heater needs to warm the metal rods (when the heater is on) and the time in which the rods cool down (when the heater is off) produces a delayed response much slower than the op amp is capable to react.
Can you give more details on the problem are you having?