We bought the K8090 to drive 8 solenoids (Magnetic valves).
After a while the card losses the connection with the pc.
Sometimes it runs for hours, sometimes for only a few seconds. (the buttons on the card keep working)
To get connected again we have to take out the usb plug and connect it again and after that make a new connection.
We have purchased a new card because we thought the problem was in the card, but the new card gives the same problems.
The problem is also not our own made software because the card also crashes on the original velleman software.
We were afraid the solenoids created a megnetic field that would interfere with the usb connection so we seperated them with about 2 meters of cable, also that didn’t help.
The solenoids are 230V and a few watts.
We powered the card with a 12V/500mA DC power supply.
The phase is connected with contact NO1 and we laid a bridge over the common relaycontacts to power them all at once.
Then we connected contact 1 to 8 to the solenoids. (neutral directly on solenoids)
PS we tested it on different pc’s and with different usb cables.
Since this is a kit it did not come witht he VDR Velleman’s part number VDR300
I don’t know if this will help and is a pure guess on my part.
I dod find this statment under features on the product page
•optional VDR (type VDR300) transient suppression for use with inductive loads
This however maybe just for the relay.
Have you tried to run the K8090 withiout the solenoids to make sure they are the cause of the problem?
I hope this may help[/quote]
Thanks for the quick reply,
We have the VM8090 that’s the pre-build card (to prevent problems )
For some reason this card is already provided with the VDR’s type 14D471, so sadly this also don’t fix my problem.
However thanks for helping me.
[quote=“VEL417”]Do you get the same behaviour without the soleniods connected?
This is important to know.[/quote]
We have tested the card today without the solenoids connected and then it keeps on going. (only power supply connected)
With the solenoids connected we tried to connect it to a powered usb hub, it also crashes.
Do you have any idea what can be the problem?
have similar problem with my homemade interface (pic16f84)
when i connect the solenoids the peak voltage of the solenoid was 300v
solenoids works on 24 volt dc.
i put large capacitor 25v 4700 microfarad on 5v(interface) and on the solenoid 250v 1mf
i also put the interface in a metallic box and the ground of the box was same on the pc tower.
that fix the problem with my interface
Since USB is a hot insertion & removal system, USB components are subject to Electrostatic Discharge (ESD). However, USB ESD protection is not yet a specific requirement of the USB specification. State-of-the-art USB ICs are manufactured on high integration CMOS processes making them extremely sensitive to damage from the high static voltages associated with an ESD event.
Hi,
I never measured the peak voltage/current, i will try.
The card is placed in a plastic container and the distance between the container and the solenoid block is about 2 meters.
Do you think a standard COM port would do beter in this case?
If so, i will look for a new card.
)