Ok, the only reason that the existing pot is left is because the circuit required it. I would prefer to use the process controller to do all the work. I have since noticed that anything that varies the resistance will likely do ok.
The vactrol mentioned or even simpler an LDR and lamp driven...
Ok, finally had a chat with the manufacturer. He sent me a diagram of an add-on board that was used for 4-20mA control loop operation of the unit, i have sketched it out and attached it.
VR1 is the existing set point control, this must remain in circuit.
I have no values for the other...
Thanks Brian,
I can see that being possible but would need some resistor padding etc to get the 0-10v signal to control the transistor properly, only trouble with that is - I am useless with discrete components, I'm ok with PLC's, Process controllers, pneumatics and maybe even valves :) but...
Thanks,
I thought it might be a tough one, maybe I'd be better on an electronics forum?
Startup and shutdown is already handled by the base machine, all I need to do is find a way of altering the position of a control knob based on a sensed temperature, scaling, limits and so on are all...
Hi all, first post:)
I have a question reagrding interface methods.
We have a printing press in the shop, it has an infrared dryer built in, it's basically 8kw of halogen lamps controlled by a thyristor stack power controller and temperature is user adjusted by a potentiometer. The printed...