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-   -   FAV valve specs (http://www.aquamist.co.uk/forum2/vbulletin/showthread.php?t=3166)

luke2152 04-03-2019 10:09 PM

FAV valve specs
 
Just brought an FAV valve from Richard. I'm going to run it off map on my ecu. Need to know the pinout of the terminals. And what voltage and frequency to drive it at. What PWM does it start to open and fully open. Thanks

Richard L 07-03-2019 09:59 AM

Re: FAV valve specs
 
use the two lower pins.
frequency: 25Hz.

@25Hz starts at 10%(min) to 90%(max)

sevennstrings 26-03-2019 07:33 PM

Re: FAV valve specs
 
Quote:

Originally Posted by Richard L (Post 24751)
use the two lower pins.
frequency: 25Hz.

@25Hz starts at 10%(min) to 90%(max)

hey Richard,

So 25Hz is very low for PWM. Usually 400 Hz and above. Does that mean this valve is not a true proportinal valve since those work at 1000Hz as well and higher.

Richard L 26-03-2019 08:26 PM

Re: FAV valve specs
 
The FAV is not a Proportion valve. Proportion valve is not suitable for this type of application.

sevennstrings 29-03-2019 07:16 PM

Re: FAV valve specs
 
Quote:

Originally Posted by Richard L (Post 24776)
The FAV is not a Proportion valve. Proportion valve is not suitable for this type of application.

why would that be Richard. There are many proportional valves available for precise control of flow for 0-20 bar or more..

can you explain what the issue would be ?

Richard L 30-03-2019 04:25 PM

Re: FAV valve specs
 
Proportional valve are also known as v"ariable lift" valve, the position of the valve is suspended between to two poles, the position of the valve is carefully controlled by a electronic servo-feedback loop driver running at a several hundred Hz. The valve design requires a very narrow hysteresis megnetic circuit.

A variable lift valve is very similar to a pump speed system, low speed=low pressure=low flow=low atomisation.
Further reading:
https://www.clippard.com/cms/wiki/hy...rtional-valves


The aquamist FAV is a (fixed lift) valve responding relatively linearly between 25-50HZ PWM drive signal.

Aquamist PWM FAV (fixed lift, constant line pressure):
Full pressure (good atomistion) at wide range PWM%. It requires a relatively simple control driver. All fuel injectors use this type of valve.

sevennstrings 31-03-2019 05:07 AM

Re: FAV valve specs
 
Quote:

Originally Posted by Richard L (Post 24780)
Proportional valve are also known as "variable lift" valve, the position of the valve is suspended between to two poles, the position of the valve is carefully controlled by a electronic servo-feedback loop driver running at a several hundred Hz. The valve design requires a very narrow hysteresis magnetic curve.

A variable lift valve is very similar to a pump speed system, low speed=low pressure=low flow=low atomisation.
Further reading:
https://www.clippard.com/cms/wiki/hy...rtional-valves


The aquamist FAV is a (fixed lift) valve responding relatively linearly between 25-50HZ PWM drive signal.

Aquamist PWM FAV (fixed lift, constant line pressure):
Full pressure (good atomisation) at wide range PWM%. It requires a relatively simple control driver. All fuel injectors use this type of valve.

That you very much Richard for the time you took to explain. I understand it now very well. I also saw a thread from the Mitsubishi forum where you explained the systems in detail.

Richard L 31-03-2019 11:16 AM

Re: FAV valve specs
 
I have a better explanation:

Proportional valve is similar to a tap.
Flow is controlled by restricting the flow path. Pressure will vary with flow.

PWM valve is similar to a on/off button.
Flow is controlled by the ratio of the press/un-press duration. Peak pressure remains the same.

Since peak pressure is maintained for best atomisation, PWM valve is preferred.

luke2152 10-04-2019 10:34 PM

Re: FAV valve specs
 
1 Attachment(s)
Well I tested the valve tonight. Spraying from a number 4 jet and a number 7 jet into plastic bottles which I would then weigh after each one minute sample on digital scales. Not 100% accurate but I tried to keep it precise.

Initially tested at 26Hz but I wasn't very happy with the results. Min usable duty cycle was 10% and it was linear to 50% and then flow barely increased from there to 100%. I took samples every 10% up to 100%.

Then tested at 11Hz. Results were better. Would operate correctly as low as 5% cycle and good linear results up to 75% which was max flow. Only took samples at min duty, 25%, 50%, 75% and 100%.

Final testing 39Hz. Poor results. Would not operate until 15% duty. More or almost maximum flow at 25%. Samples at min duty, 25%, 50%, 75%, 100%.

So based on that 11Hz was definitely the most linear flow rate in the test. I couldn't set the freq any lower on my ecu but I imagine something like 5Hz might produce better results still. I'm not sure what pressure my pump was delivering but max flow was a little lower than I expected.

Attached is my data table. I really should have taken more samples at 11Hz and 39Hz but it was taking too bloody long and the trend was pretty obvious.

Richard L 11-04-2019 12:25 AM

Re: FAV valve specs
 
With a Aquamist system, you should get the result below. I am unable to give you support on this as it is not our controller.

Magenta = PWM duty cycle (5V=100%)
Cyan = FAV flow sensor output with 1mm jet (4.5V=F-max).

http://www.aquamist.co.uk/NEW/FAV-log-ss.jpg


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