closed loop. i need to have a dual zone controller to manage 2 type j thermocouples. One thermocouple monitoring the heater temp and one monitoring the temp inside the hose
Thanks, I have checked with omega. they supply the individual components... I need to find out if someone already has a design for this or should I start "from scratch"
I was thinking along the lines of using an Omega product with PID function for control, with the feedback being one of your zones. Then monitor your second zone externally and use that value as the basis to adjust the PID settings in the Omega part (via a serial interface). You could offload some display, control, and coding into the Omega block.
I just did a cursory look at their parts. How far down the Google road have you gone in looking at off-the-shelf industrial controllers? We tend to design our own stuff, but if this is a one-off or small volume you might find something that gets you close that's already on somebody's shelf.
Your query is too much wide. Please be more specified. Can you write system requirements which the design must fulfil? I can guess from your words that you want to build a heating controlled system (closed loop system). I established before a system sense the current temperature of a certain zone, and then record it on a database with time and date of record. I depend on my system on a microcontroller and a temperature sensor. Microcontroller is not the only possible way, you can replace microcontroller by any electronic circuit by using comparator with hysteresis.
Till you send us system requirements, I can help you by simple steps to build your own design Ask your self these questions then write the answers in a paper draft:
- How many zones you want to control?
- Sure it is a closed system loop?
- What is the operating temperature of your system?
- What are the maximum and the minimum temperatures you want to measure?
- What is the action or the response your system will take in case of the temperature exceeds certain level or in case the temperature gets below a certain level?
- How you will supply power to your system (DC power supply, chargeable batteries, non chargeable batteries, solar cell, etc)?
- Are there any limitations on budget of the project?
- If your system is controlling different zones you will need a different dedicated sensor for each zone.
- If your system will work in flammable environment you must consider the maximum consumed voltage and current of your system are on range according to safety considerations or not. As example any electronic device working in petroleum well, its voltage must not exceed 5V.
- Don’t forget to make a power consumption reduction plan of your design.
I hope if that could be helpful