??? 03/07/04 10:10 Read: times |
#66166 - RE: Solenoid operated Pneumatic valves Responding to: ???'s previous message |
Thanks a lot to all you guys for providing your valuable inputs specially Mr. Kai Klaas. Armed with this knowledge I will go ahead with testing my spot welding machine. In first attempt I will use mechanical relays since I had built the board with relays far earlier let's see how it works.
uC -> Optocoupler -> ULN2803 -> Free wheeling diode -> Mehchanical relay -> Snubber -> Load. If it doesn't work I will make a new board with following configuration. uc -> ULN2803 -> SSR -> Snubber -> Load and a line filter. Apart from whats mentioned above I also learnt following points. 1. PS/2 keyboards operation near welding area are not a problem and can be used normally if parity check is done on the data from keyboard. 2. LCD sicne continuously refresh their data are almost immune to nearby welding interference. 3. Neither optocouplers nor separate power supply is needed to interface keyboards and LCD displays. With this I would request the moderators to close this thread as I am fully satisfied with the discussion. |