Mains input current waveform into fan heater?

[ocset]

motor will get real upset about the waveform

Thanks, it will be 1 minute ON, 2 minutes OFF...repeated...

[Gyro]

I'm starting to think that treez is just trolling... 

I don't know about trolling, but his habit of drip feeding information (and intentions) after a reasonably simple looking OP certainly makes it difficult to 'see the wood for the treez'. 

[T3sl4co1l]

Just WHY are you modifying cheap ass shit like these heaters?

Thanks, in our office, 1kw is often too hot, but we can't set it to say 300w, so we wish to duty cycle the fan (eg 10 seconds on, 20 seconds off, repeating) so that it gives , on average, 300w
 

Just go buy a different heater and stop being daft.

Thanks, as you know, many people cannot afford a better heater.
But a little box of tricks like i describe can help them get through the winter without having to make too many visits to the food banks.

For all those of you following these threads -- keep these above quotes in mind.

Presumably, the OP has found himself in a tight situation.  Whether through poor finances or what -- who knows -- he has only managed to find a job, so similarly fraught, that they can hardly afford to give him minimum wage (that is, in pocket -- less taxes, interest, rent and what have you).  Perhaps worse than that, as he is unable to afford a mere heater.

As for those situations, whether his behavior can be changed, or not, who knows; but we should at least keep in mind generosity, for those less fortunate than we are.

Tim

[Delta]

So you are planning to market a £25+ add-on product to people who can't afford half that price for a heater with a thermostat?

Superb.

[floobydust]

I question the narrative - is this a product development post, or a poor man's solution soliciting help with our pity?

OP has firmware to write, a HV enclosure, heatsinks, parts costs, regulatory risk... and that's false economy.
A proportional PID controller is $10, 4kW triac phase-controller $2, on eBay or Ali.
Compare to $1,000+ in engineering design work... when a high/low heater is all that is needed.

It feels like manipulating the community to get design help on something, related to mains transients on LED lighting....

[Gregg]

Just WHY are you modifying cheap ass shit like these heaters?

Thanks, in our office, 1kw is often too hot, but we can't set it to say 300w, so we wish to duty cycle the fan (eg 10 seconds on, 20 seconds off, repeating) so that it gives , on average, 300w
 

Just go buy a different heater and stop being daft.

Thanks, as you know, many people cannot afford a better heater.
But a little box of tricks like i describe can help them get through the winter without having to make too many visits to the food banks.

For all those of you following these threads -- keep these above quotes in mind.

Presumably, the OP has found himself in a tight situation.  Whether through poor finances or what -- who knows -- he has only managed to find a job, so similarly fraught, that they can hardly afford to give him minimum wage (that is, in pocket -- less taxes, interest, rent and what have you).  Perhaps worse than that, as he is unable to afford a mere heater.

As for those situations, whether his behavior can be changed, or not, who knows; but we should at least keep in mind generosity, for those less fortunate than we are.

Tim

Not to judge or diagnose the OP, but I have witnessed this type of behavior in coworkers at least 5 times in the past.
It starts out rather innocently with the person seemingly acting in a devoted or obsessive compulsive manner.  The objects of interest are of vary narrow scope and the person affected refuses advice that is contrary to what they envision.  They often skip from one subject of manically devoted concentration to another.  As time goes on, they get worse and worse, until they can hardly function or communicate with others.  They get paranoid that nobody sees things the way they do.
In the people I have known exhibiting these symptoms, the cause has been methamphetamines.  It is really too bad that some intelligent people get caught up in this trap.