110v ac motor controlled by 24v driver-controller board?

[dlang]

Hello,
We have a driver-controller board that was engineered to run a 24v DC motor using a microcontroller. The board also has a 5v step-down curcuit to power the microcontroller.

We want to use this board to drive a 110v AC motor. Does anyone know of an add-on curcuit or design to accomplish this?

Thanks.

 

[fangas]

Howdy,

If all your board did was turn this DC motor On/off and nothing fancy, like speed control. My first thought would be to insert the control input of a solid-state relay into your curcuit in place of the DC motor. And use the output of the SSR to control the AC motor.

If it did fancy stuff, like speed control, that's a different thing altogether.

Might be other ways, that just strikes me as easiest.

Hope that helps.

Ed

 

[OperaHouse]

Just one warning. If you use a reversing AC motor, be sure to insert a time delay between forward and reverse at a minimum. I came into a project that was burning out TRIAC based solid state relays. If both TRIACS turn on at the same time because of a noise glitch in the line, the motor load looks like a short. Adding some extra resistance in the line and heavy noise suppression can help this. Our solution was to just go to a mechanical relay.

 

[Mike2468]

Since you have a micro controller coordinating this, I'd have a tendency to use a solid state relay to keep it simple, and keep it electrically clean. Use a SCR-based solid state relay, that has a high dv/dt, and probably add an MOV across the L1/T1 terminals for added protection. The inrush on the AC motor is probably 6-9 times the running amps, so just size the solid state relay accordingly. You can google for solid state motor starters to see several good suppliers.

 

[blacksea]

Hi All guys,
maybe strongly recommend to use a driver intended for AC motor control due to significant difference of control methods for AC and DC mootrs.

 

[dlang]

Thanks all for your input.

Any suggestions on where to find a AC motor driver for this?

I'm using the Nat Semi LMD18245 for the motor now.

Will I need a starter for the AC motor?

 

[fangas]

Hi Dave,

Your question needs a little clarification. What looked like a straight forward replacement of a DC motor with an AC, now appears different. As, a quick look at the data sheet for the LMD18245 shows it to be a driver for a stepper or DC servo. This takes the simple replacement question into a different area.

Could you send a little more info on your system?

Ed

 

[dlang]

Oh I'm sorry.

Ok, it's a 2 phase stepper motor 3A, 24v DC. I use 2 of the LMD's and they are controlled by a microcontroller.

Did you need anything else?

Thank-you.