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UK toilet extractor fan

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Zero999:

--- Quote from: themadhippy on August 20, 2021, 01:16:12 pm ---As usual Bigclive has already dissected one.


--- End quote ---
The values seem to be on the low side: 470µF & 440k. I'll have to do some calculations to see what the delay will be.

floobydust:
How can you import and sell cheap chinese bathroom fans in the UK, when they have no safety or agency approvals? OP, ensure your product is legit.
Yet we're worried about fusing and the ET Wiring Regulations. Like a fox in the henhouse.

The Big Clive fan, wasting 1.2W all the time- looking at the cooked 22k resistor, phenolic pcb, unknown plastic housing (UL 94V??) it's your usual POS.
I've seen other fans with electronics such as MCU and PIR sensor, use instead a capacitive dropper.
The only safety component is the dropping resistor, hopefully they are infallible. Not so with thick-film TO-220 resistors for some reason, I've seen them go lower in value with abuse.
This looks like metal-oxide running hot 24/7 just to power a CMOS timer  :palm:

Gyro:

--- Quote from: Zero999 on August 20, 2021, 07:21:08 pm ---The values seem to be on the low side: 470µF & 440k. I'll have to do some calculations to see what the delay will be.

--- End quote ---

I think Clive is out on the pot value, he didn't measure it but said it was marked C05, so it might be 500k (or even 5M?). The 220k fixed resistor is a minimum value limiter, so I would expect the pot to be significantly higher (I'm not sure what the minimum and maximum times are).

Zero999:

--- Quote from: Gyro on August 20, 2021, 07:57:21 pm ---
--- Quote from: Zero999 on August 20, 2021, 07:21:08 pm ---The values seem to be on the low side: 470µF & 440k. I'll have to do some calculations to see what the delay will be.

--- End quote ---

I think Clive is out on the pot value, he didn't measure it but said it was marked C05, so it might be 500k (or even 5M?). The 220k fixed resistor is a minimum value limiter, so I would expect the pot to be significantly higher (I'm not sure what the minimum and maximum times are).

--- End quote ---
It looks like 605 to me, or perhaps 1605 which is 6M, or 16M. which are odd values, but wouldn't be surprising.

It took a screenshot and upped the contrast a little to make it clearer.

Gyro:
Sounds right to me, I'd guess at 6M rather than 16.

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