Slave element IAC

[comnean]

Hy,
What type of IAC you consider be the best - a freqventie type or a step by step motor type.
Sorry for english

 

[TheBlacksmith]

I always preferred the frequency (solenoid) type over the stepper motor. In my experience, faster response to changes, so engine RPM varies less (less stalling and flare) and they were less likely to get stuck.

Blacksmith

 

[comnean]

Hy, Blacksmith
Your opinion is the best but I need your opinion about driving mode of this. Is preferable to pilot this in variable freqv. or in variable amplitude.Majority of car makers prefere in frecv. modulation but I prefere variable amplitude mode because on my experience high freq. generators are not so reliable.
Sorry for english

 

[TheBlacksmith]

My experience again, was with frequency switching, not amplitude. I found it to be satisfactory. It was not so much a high frequency generator to my way of thinking, as it was a duty cycle modulation. No power was zero and IAC was at minimum, continuous power application was 100% and IAC was at maximum, switching in between gave intermediate position. As stated, it could go from say 25% to 50% faster than the engine could, so undershoot and overshoot of target RPM was minimized. Amplitude, I think could be affected by resistance changes with temperature or corrosion accumulation on connections and introduce additional errors to be compensated for.

Blacksmith

 

[comnean]

Hy, Blacksmith,
No, is wrong, amplitude modulation have same effect that freq. modulation.In both case the problem is only capability of slave element. Important is the law described in the electronical part.I have experience with a big freq. range and I,m satisfied for a 40 Hz. freq.In case of big freq. maybe 2-3KHz. problems with pulse generating are biggest. More if a few freq. sources are necesarry is possible to obtein unfavourable freq. composition. The singular advantage of freq. modulation is bracking of solid deposits (oily burned deposit)that appear on external mouving parts.
What opinion You have?
With big respect and sorry for my english.