Newbie with AC motor
Newbie with AC motor
(OP)
Hello to you all,
I'm from a mechanical background and I'm very new to the electric world. I'm planning on building a little contraption that shoots pet food accross the room (no kidding). I recently scavenged an electric motor from a food beater/blender. All it says on it is : 230V, 50Hz, 170W. It all works fine when I plug it. I live in Australia and everything here is 230V, so no worries there.
My question is: The motor spins way too fast at the moment, how can I slow it down ?
Thanks in advance for any help,
Cheers ;)
I'm from a mechanical background and I'm very new to the electric world. I'm planning on building a little contraption that shoots pet food accross the room (no kidding). I recently scavenged an electric motor from a food beater/blender. All it says on it is : 230V, 50Hz, 170W. It all works fine when I plug it. I live in Australia and everything here is 230V, so no worries there.
My question is: The motor spins way too fast at the moment, how can I slow it down ?
Thanks in advance for any help,
Cheers ;)





RE: Newbie with AC motor
RE: Newbie with AC motor
This motor sounds pretty big for what you want to do. If you had an old variable speed electric drill, it might do the trick.
RE: Newbie with AC motor
I would expect that this motor is probably a universal motor. Check and see if it has brushes. If it does, then it can be controlled by varying the voltage applied to it. For a one off, this is probably best achieved by going to one of the Dick Smith or similar store and buying a motor speed controller kits. NOTE : These can not be used with induction motors unles they are a special high slip induction motor.
Varying the voltage will vary the torque and this in turn will cause the motor to run at a lower speed, depending on the load torque.
Best regards,
Mark Empson
http://www.lmphotonics.com
RE: Newbie with AC motor
Is it a pet croc or something?
"Venditori de oleum-vipera non vigere excordis populi"
RE: Newbie with AC motor
Here is the motor in question:
http://members.westnet.com.au/ultragotcha/ACmotor.jpg
Will a triac work with this kind of motor?
I went to an electornics shop today and asked to see a triac. There were a few different models with different tolerances to amperage and max voltage. I'm gonna start reading some electronics basics in order to, hopefully, design a little circuit board with a triac and potentiometer to control the motor speed. I'll keep you posted on how it goes ;)
RE: Newbie with AC motor
Dpc mentioned about using a variable speed drill/screw driver, you can couple it to the equipment with the choke; some drills have a trigger with a rotating nut to maintain it working at desired speed.
RE: Newbie with AC motor
I'll politely diagree with you because I can see what I think are brush holders on the motor. The covers appera to be a blue colour. One is at the very bottom of the photograph immediately below the thin white lead coming out of the glass fibre sleeve, and the other is parly obscured by the black lead at the top left of the motor body.
If this is the case, Marke's comments regarding control of universal motors apply.
Ultragotcha,
A triac on its own will not help you. You need the rest of the circuit too. You can buy a mass-produced item made in China or wherever for less than you can buy the components for in the West. What are you planning to feed with this thing?
------------------------------
If we learn from our mistakes,
I'm getting a great education!
RE: Newbie with AC motor
Don't worry, like you said, it’s a great education.
RE: Newbie with AC motor
RE: Newbie with AC motor
There is a way to get around some of the problems that inductive loads introduce to light dimmers. You can wire the light dimmer to your motor and add a resistive load in parallel with the motor. I would suggest a 500 ohm resistor rated for at least 120 Watts. If you'd rather not buy the resistor, you can use a 100 Watt light bulb in parallel with the motor instead of the resistor.
RE: Newbie with AC motor
It's not the Crocs you gotta worry about,.............
It's the Yabbies that Eat them.
Tom
RE: Newbie with AC motor
I would be following up the earlier sggestion of the variable speed Electric Drill.
not only do you get a variable speed but you also get a choice of a two speed gearbox. Somewhere between the two you should be able to find the optimum speed.
The best part is that all of the design and experimentation has already been done at someone elses expense.
170 Watts is a fairly small power rating so even the smallest Drills should be enough. The one I have is 500 Watts and it is not really all that big in the scale of Power drills.
Take a walk through the tool shop in "Bunnings", I am sure you will see something there
your mechanical background should be able to fashion some mounting arangement to your "Croc Feeder"
Tom