T435-600B Issue with Solenoid Pump and diode

[pVAN .1]

Hello everyone,

I'm currently facing an issue with controlling a solenoid pump using a triac T435-600B in a configuration that includes a diode. The power supply for both the triac and the pump is the same, and it's triggered by an opto. I am unable to control the pump when the diode is connected in series with the solenoid pump coil. However, when I tested a similar setup with a solenoid valve and without the diode, it worked as expected. Could it be the phase shift between voltage and current due to the coil of the solenoid?

 

I'm not sure what is causing this issue or how to resolve it. Has anyone encountered a similar problem or have any suggestions on how to troubleshoot this situation? I'm open to ideas and solutions.

Any help or guidance would be greatly appreciated. Thanks in advance!

[Peter BENSCH]

Welcome, @pVAN .1​, to the community!

the diode is not visible here - how is it connected?

Regards

/Peter

[pVAN .1]

Hi Peter,

The diode is on the pump connector, in series with the coil. The pump is connected to the JSx5 port. It is the "MONO SERIES SOLENOID PUMP" 230v/50Hz from Fluid-O-Tech. (https://www.fluidotech.it/site/assets/files/1331/mono-solenoid-pumps-datasheet.pdf)

I suppose that the diode allows for half-wave voltage rectification to create the oscillation movement in the pump. However, due to the pump's coil, there could be a phase shift between the voltage and the current. As a result, the solenoid would experience a voltage only when the sinusoidal waveform is around 0?

[Peter BENSCH]

Well, if you only leave a half-wave to both the valve and the control circuit, this control can also no longer work properly because its supposed to work with a full sine wave. I could imagine that the triac then only works like a thyristor and needs a different control.

To be on the safe side, you would have to check again with a simulator whether this is feasible at all and which further component changes might be necessary.