Hello
A friend asked me to help him in building a speed controller circuit for a 220V 0.6A AC motor which is to be used in his BS senior project (Mechanical Engineering).
I'm not familiar with power AC electronics, but I found this circuit and seems to be easy..
The circuit with some details http://www.aaroncake.net/circuits/acmotcon.asp
U1 is a DIAC Opto-Isolator, they are not available in my country.. I'm thinking if it works if I make one using a white bright LED and a DIAC in series with a photoresistor (facing the LED), and putting them in a small dim case. Is there any other solution?
Another question.. in the parts list they say R13 is a 47 Ohm 1W Resistor, and that larger loads will require a smaller value.
If the motor is rated 0.6A, I see the real current will be more than that when there is a mechanical load (blades/fan in this case) and I assume for now the current would be about 1A. And as it's clear from the circuit, the voltage across this resistor will be used to voltage supply a part of the circuit..
Since the load current is about 1A, I see R13 should be about 20Ω 50W resistor (20Ω x 1^2 = 20W...). The voltage drop across the resistor will lower the load voltage a little(comparatively), but it is ok.
Also, if 20Ω resistor will be used, the voltage across it will be around 20V which will not require a transformer? right?
Regards,
Hazim
A friend asked me to help him in building a speed controller circuit for a 220V 0.6A AC motor which is to be used in his BS senior project (Mechanical Engineering).
I'm not familiar with power AC electronics, but I found this circuit and seems to be easy..
The circuit with some details http://www.aaroncake.net/circuits/acmotcon.asp
U1 is a DIAC Opto-Isolator, they are not available in my country.. I'm thinking if it works if I make one using a white bright LED and a DIAC in series with a photoresistor (facing the LED), and putting them in a small dim case. Is there any other solution?
Another question.. in the parts list they say R13 is a 47 Ohm 1W Resistor, and that larger loads will require a smaller value.
If the motor is rated 0.6A, I see the real current will be more than that when there is a mechanical load (blades/fan in this case) and I assume for now the current would be about 1A. And as it's clear from the circuit, the voltage across this resistor will be used to voltage supply a part of the circuit..
Since the load current is about 1A, I see R13 should be about 20Ω 50W resistor (20Ω x 1^2 = 20W...). The voltage drop across the resistor will lower the load voltage a little(comparatively), but it is ok.
Also, if 20Ω resistor will be used, the voltage across it will be around 20V which will not require a transformer? right?
Regards,
Hazim