Hi everyone,
I am working on a project that uses a microcontroller PWM pin to control the pressure of a vibration pump. I have the microcontroller part working, but I am a bit stuck with the opto triac part.
The opto I am using is the VO2223A from Vishay. Its AC side is rated to 0.9A, which is well in excess of the 330mA drawn by the pump (40W @ 120V)
Its datasheet is here - https://www.vishay.com/docs/81166/vo2223.pdf
While I have used DC optocouplers & zero crossing SSR's before, I am not very familiar with random fire opto triacs. Would I be correct to drive the pump from pins 6 and 8 and ignore the gate on pin 5?
On the DC side of the VO2223A I am using a 370 ohm current limiting resistor. I calculated this from the datasheet's Trigger Current of 10mA and Forward Voltage of 1.3V.
(5-1.3) - 0.010 = 370.
Closest value without exceeding the max values from the datasheet is 390 ohm.
When I connect AC power to the pump via the VO2223A (I have tried connecting via pins 6 & 8, as well as pins 5 & 8), the pump begins to hum, even when the microcontroller is disconnected from power. Can anyone tell me why this is happening?
My research leads me to believe that I will require a RC snubber, however all of the application notes and schematics I have found are for 240V inductive loads, while the pump is only 120V. How do I calculate the values of R and C for this?
Any advise is most welcome.
Thank you in advance
I am working on a project that uses a microcontroller PWM pin to control the pressure of a vibration pump. I have the microcontroller part working, but I am a bit stuck with the opto triac part.
The opto I am using is the VO2223A from Vishay. Its AC side is rated to 0.9A, which is well in excess of the 330mA drawn by the pump (40W @ 120V)
Its datasheet is here - https://www.vishay.com/docs/81166/vo2223.pdf
While I have used DC optocouplers & zero crossing SSR's before, I am not very familiar with random fire opto triacs. Would I be correct to drive the pump from pins 6 and 8 and ignore the gate on pin 5?
On the DC side of the VO2223A I am using a 370 ohm current limiting resistor. I calculated this from the datasheet's Trigger Current of 10mA and Forward Voltage of 1.3V.
(5-1.3) - 0.010 = 370.
Closest value without exceeding the max values from the datasheet is 390 ohm.
When I connect AC power to the pump via the VO2223A (I have tried connecting via pins 6 & 8, as well as pins 5 & 8), the pump begins to hum, even when the microcontroller is disconnected from power. Can anyone tell me why this is happening?
My research leads me to believe that I will require a RC snubber, however all of the application notes and schematics I have found are for 240V inductive loads, while the pump is only 120V. How do I calculate the values of R and C for this?
Any advise is most welcome.
Thank you in advance