i want to build programmable logic controller (PLC)?

Question

suggest me some websites

Answer 1

The easiest way to make a programable logic controller is by using an EPROM. EPROM stands for E-Programamble rom. I forgot the E. Basically you can write some logic functions and hook this do hickey up to your pc and it will "flash" it to create the specified logic function.

If your too lazy or too broke (my case) to do this you can use a virtual state machine. This is done by using a memory chip whose addresses reference output data. You input the address "INPUT" to the memory. and you have the memory programmed to "OUTPUT" the desired logic funtion. This is called a FPGA, field programmable logic array. You can buy em for like $300 or make one on a bread board.

Good luck.

Answer 2

A PLC is one of the most basic control systems and an excellent way to understand automation. What may be a bigger help and much harder to grasp is HVAC terminology. Heating, ventilation and air conditioning is a strange world, often simply assigned to the HVAC guys to make to make it work. If you are to do any large scale automation, there will be an HVAC component and he who has a little more knowledge will be way ahead of the others. Another thing to look into is the new green building concepts, many are so new they aren't in the text books yet, but you can follow them on-line.

Answer 3

Modern PLC's are microprocessor based and outside the scope of home build. They are also extremely inexpensive to buy.

Answer 4

Why do you specifically want a PLC? You can do lots more with a BASIC stamp:
http://www.parallax.com/html_pages/products/basicstamps/basic_stamps.asp

Answer 5

Why? do something better, there are tons out there. Technology is developed too far..