[SOLVED] Electro Valve Problem...?

[Js_Ong]

Hi All,

I am testing my program using microcontroller to control the electric valve 12V. The program is wrote to control the valve for operating the machine which will have repeat cycle. The program works well and the valve works as programmed. I had wrote to loop the programe so the valve can continously turn on and off. The weird thing is, the valve runs well continously for about 10 rcycles, and then let say it does not turn ON at the 11th cycle, but it will turn ON again on the 12th cycle. Just like it alternately stop for one cycle. Why is this happenned and how to solve this?

I have 3 valves, and only one valve definately will behave like this, second valve after more cycles will behave once or twice, third valve never happen.

I use TIP120 as the driver to drive the valve and there is also free wheel diode on the valve.

 

[barry]

1) Software bug
2) hardware problem. (driver?)
3) bad valve.
4) overheating valve.

You're going to have to do some diagnostics. Look at some things with an oscilloscope, for instance.

 

[KlausST]

Hi,

Maybe a overflow in software,
Maybe the microcontroller resets.
Maybe EMC problem.

Klaus

 

[c_mitra]

I have 3 valves, and only one valve definately will behave like this, second valve after more cycles will behave once or twice, third valve never happen..

You just interchange the valves and try to figure out whether the problem is in hardware or in software. Are you giving the valve time to rest before asking it to turn on again?

Perhaps you are driving them too hard; there can be too many reasons.