ac motor speed control

[aegdr]

I try to use 18x to control the speed of ac ventilation fan with pwmout command & opto triac tlp3063 in conjunction with another triac for switching. No matter how I change the period & duty cycle, all I can have are full speed and a very slow speed. Can anyone help me to sort this out?

[ylp88]

You should try posting this on the "PICAXE Forum", not on the "Software Feedback" forum - you should have more response there.

I'm not all too familiar with Triacs, so I can't really help, sorry.

<b><i>ylp88 </b> </i>

[evanh]

Replace the 3063 with a 3023. Depends on the motor type but this will prolly help.

Don't expect a great variation of speed from AC motors unless you have control over the frequency.


Evan

[c930174]

Ceiling (exhaust) fans are almost invariably synchronous: they synchronise to the mains supply frequency (50Hz in Australia gives either 3000rpm or 1500rpm less a little for losses Eg 2950 &amp; 1450rpm).

If you're referring to the big ceiling fans (hanging from the ceiling), they use phase shifting by switching mains-rated capacitors in and out of circuit. You might have some luck using triac-capacitor combinations but its a bit dangerous for an experimenter.

Alternatively, synch the PICAXE off the mains freq. and selectively switch the triac on and off for each half cycle. Also dangerous for the experimenter.