Hello,
I am an Mech/Elec Engineer in a food production factory, i was today asked to fix a machine which at first seemed a simple fault- a 5 port, double acting solenoid pneumatic valve was not changing although the solenoids was getting 24VDC.
We have no info on this particular machine and i have never worked on it before but there is a computer hard drive in the panel, Balder drive/interface circuit board and servo amplifiers.
Basically after a lot of messing about including changing solenoid/valve the valve would not change unless i connected it to the workshop bench power supply (24v). The interface card has outputs to feed various solenoids and the ones i needed had 24v on them when on but would not provide enougth power to move the spool in the pneumatic valve.(the outputs did not drag down when the load was connected)
The only way i got the machine to run in the end was to run 2 leads direct to solenoid pins from the outputs and do away with the caps which contain LED indicators. I had already tried new leads/caps which did not help and these are the same parts that have always been on the machine.
My electronics is limited but if anyone can explain whats happening it would be appreciated. I thought if we had the correct voltage weather its from a bench power suppply or card it should work as the solenoids are only low power.
I have experiened before tranistor outputs playing up but usually the output voltage drops when the load is connected?
I am not sure if this card has relay or transistor outputs but can both cause this fault i.e. we have the voltage but cant supply the current.
Is it possible the card is failing and just by bypassing the extra load of the caps there is just enougth to energise valve.
I am sure there is an electronic explanation for this, thanks.......
I am an Mech/Elec Engineer in a food production factory, i was today asked to fix a machine which at first seemed a simple fault- a 5 port, double acting solenoid pneumatic valve was not changing although the solenoids was getting 24VDC.
We have no info on this particular machine and i have never worked on it before but there is a computer hard drive in the panel, Balder drive/interface circuit board and servo amplifiers.
Basically after a lot of messing about including changing solenoid/valve the valve would not change unless i connected it to the workshop bench power supply (24v). The interface card has outputs to feed various solenoids and the ones i needed had 24v on them when on but would not provide enougth power to move the spool in the pneumatic valve.(the outputs did not drag down when the load was connected)
The only way i got the machine to run in the end was to run 2 leads direct to solenoid pins from the outputs and do away with the caps which contain LED indicators. I had already tried new leads/caps which did not help and these are the same parts that have always been on the machine.
My electronics is limited but if anyone can explain whats happening it would be appreciated. I thought if we had the correct voltage weather its from a bench power suppply or card it should work as the solenoids are only low power.
I have experiened before tranistor outputs playing up but usually the output voltage drops when the load is connected?
I am not sure if this card has relay or transistor outputs but can both cause this fault i.e. we have the voltage but cant supply the current.
Is it possible the card is failing and just by bypassing the extra load of the caps there is just enougth to energise valve.
I am sure there is an electronic explanation for this, thanks.......