Motor speed controller

I need to control the speed of a 1/3HP 120V AC motor. This motor/speed cont rol would go onto a wood lathe and replace the pulley system which is now i n place. Does anyone know of a solid state speed controller that I could pe rhaps build to to this? Thanks, Lenny

Reply to
captainvideo462009
Loading thread data ...

Need more information about the 1/3 HP AC motor.

Mikek

Reply to
amdx

If this is a universal type motor, one with brushes, you can use a variac (Adjustable Auto Tranformer).

If this is a squirrel cage type motor, then it either has a capacitor for start/run or winding, those you aren't going to control very well, especially if it has a centrifugal switch in it! that would be the thing you hear click inside the motor when it starts up. I guess if you could get your hands on a phase wound rotor you could vary the rotor via a rhostat :)

But really, it seems that a universal motor would be the simplest for you.

If you are not sure what you have, check for brushed, if they exist and you know it's an AC motor, then that is what you.

P.S. If you do have a 3 phase AC motor you can get a inverter that will operate from single phase to generate a three phase. That way you can vary the speed via the inverter. But I think that will cost you more than getting a uni motor with variac.

Jamie

Reply to
M Philbrook

Pulley system increases torque at low speed of cutting Electronic gubbins can only decrease torque at low speed

Reply to
N_Cook

On Monday, October 19, 2015 at 7:07:47 PM UTC-4, snipped-for-privacy@gmail.com wro te:

ntrol would go onto a wood lathe and replace the pulley system which is now in place. Does anyone know of a solid state speed controller that I could perhaps build to to this? Thanks, Lenny

I think that this motor came out of a sump pump of the type that stands on the top of a sort of 3 foot pedestal. The pedestal would then go down into a hole such as the basement floor. Float switches would turn it on to keep the cellar from filling up with water.

This motor has no brushes and I'm fairly certain that it has a start windin g because you can hear the centrifugal switch engage and disengage during s tart up and slow down. I do not have the exact speed information at hand ho wever I do know that this motor runs at around 3000RPM. There is also very large capacitor on it as well.

So from what I'm reading here is there no real practical way to control the speed of this type of motor other than (as Mr. Cook mentioned) using a ste pped pulley arrangement? Lenny

Reply to
captainvideo462009

You would hardly notice any difference with a well-designed, modern controller. I bought one for a 415V 3ph industrial lathe I bought, which enables me to run it from 240V 1ph. The low speed torque is astounding - and the soft-start setting removes the lethality of hitting the start button when you've left the key in the chuck! Well worth the money - and you can still use gearing and pulleys with it for total versatility.

Reply to
Cursitor Doom

On Tuesday, October 20, 2015 at 1:10:15 PM UTC-4, snipped-for-privacy@gmail.com wr ote:

rote:

n the top of a sort of 3 foot pedestal. The pedestal would then go down int o a hole such as the basement floor. Float switches would turn it on to kee p the cellar from filling up with water.

Is a sump pump motor intended for continuous operation? Or is it a duty cy cle type motor? Wondering whether it will stand up to lathe operation.

Reply to
Tim R

** Torque from an electric motor depends mainly on current flow in the windings, so if a controller can supply the rated full load current at low rpms there is no loss of torque.

Controllers for induction motors ( aka Variable Frequency Drives) reduce the AC frequency and voltage fed to the motor to reduce rpms. Current flow is monitored so the windings do not overheat when the motor is heavily loaded or stalled.

But if increased torque is what is needed at low speeds, stick with the pulley system.

... Phil

Reply to
Phil Allison

My sump pumps run for as little as 30 seconds per hour to almost continuous operation. The temperature will depend on the load.

Reply to
hrhofmann

Sell: China Shenzhen ZHAOWEI Machinery & Electronics Co. Ltd engages in designing , manufacturing and marketing all kinds of electric motors. They are mainly suitable for the following applications: smart home application used in sm art kitchen and laundry, medical instrument for personal care, smart E-tran smission applied in automobile, industry automation applied in telecommunic ation and a great variety of plastic/metal planetary gearbox in different s izes. In order to develop the oversea market, we are current seeking new partne rs around the world to create a bright future together. ZhaoWei is a right choice and excellent partnership with sincere services.

Company: Shenzhen ZHAOWEI Machinery & Electronics Co., Ltd URL:

formatting link
Contact: Anny Liu Tel?+86-755-27322652 Fax?+86-755-27323949 E-mail: snipped-for-privacy@zwgearbox.com Add: Blk. 18, Longwangmiao Industry Park, Fuyong Tn., Bao?an Dist., Shenzhen 518103, Guangdong, China

Reply to
zwgearbox

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.