I have a small toilet fan which is quite noisy and far too powerful for what we need. I'm looking for a solution where I could reduce AC 240V to AC 110-150V with minimum amount of components. Any transformer is out of question. Simply, no room for it. Initially, fan had a PIR sensor in the middle which was removed and now I have some space for components. 6x5cm and 2cm height. I know, it's not wise to use a resistor to reduce the voltage. Is there anything simple I could use in that space? I have more than basic experience in electronics but I didn't practice for 30 years. Sill, I understand components, diagrams, PCBs, multi-meters and can use a soldering gun. Anything I could get on ebay or assembly myself? Thank you all.
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Look for SCR Dimming – Huisman Dec 26 '19 at 21:40
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Some folk prefer to have a noisy fan to save their embarrassment. Regard it as a feature. – Andy aka Dec 27 '19 at 11:13
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Simply use capacitor in series. You are talking about bathroom fan, so I think this power is about 20...30W, it means current is about 0.1A, so to loose 100V you need reactance about 1kohm - so something between 1.8...3.3uF should be enough. Of course, DO NOT use electrolytic capacitors - only HV MKSE, MKS or polypropylene capacitors with breakdown voltage > 600V.
Tony Stewart EE75
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1I agree. 1.2uF MKS cap to split a 20W fan with 10 VARs to half power. – Tony Stewart EE75 Dec 26 '19 at 23:50