I've never heard of a soft-start "Module".
Every Motor and Load on that Motor is different,
and any Soft-Start system is going to have to be custom calibrated to suit the conditions.

There are certainly far more elaborate, and expensive, schemes.

You've been given 2 options that will work, both are cheap and simple,
we could all speculate forever on which one checks the most number of boxes.

What more do You want out of this project ?
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Absolutely nothing , people have just been kind enough to offer their advice which has been gratefully received.

 

The relatively slow "ramp-up" of the ICL Resistor may actually be too slow.

What is "too slow"?
The current will just increase as the resistance drops until the motor starts.

 

There are also schemes for using a series capacitor for current limiting, such as in many of the ceiling fans. A benefit is less heat produced, the downside is a lack of information as to how to size the capacitor. It might also work to use a triac light dimmer , which could also probably extend the life of the projection lamp.

 

There are also schemes for using a series capacitor for current limiting,

But you don't want to significantly limit the current all the time, just at startup.

 

Just a thought...
If deciding on using a bulb, would the projector's bulb work?

 

Just a thought...
If deciding on using a bulb, would the projector's bulb work?

Good thought , but it’s a xenon bulb so no filament as such . Thanks though

 

I don't know what the present use is for the Projector,
but normally a full sized 35mm-Projector must be very responsive when being started as it's
starting normally must be timed in a reasonably accurate manner
to coincide with other Theater-Events, or a second Projector..

Possibly this is not an issue considering the Projector's anticipated usage.

Considering this likelihood, the ramp-up-time should probably be less than 0.5-seconds.

This requirement, or lack thereof, needs to be verified with the Thread-Starter.
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I don't know what the present use is for the Projector,
but normally a full sized 35mm-Projector must be very responsive when being started as it's
starting normally must be timed in a reasonably accurate manner
to coincide with other Theater-Events, or a second Projector..

Possibly this is not an issue considering the Projector's anticipated usage.

Considering this likelihood, the ramp-up-time should probably be less than 0.5-seconds.

This requirement, or lack thereof, needs to be verified with the Thread-Starter.
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Machine are usually programmed to ramp up to speed over 4 seconds or so , this allows for stabilisation in the film transport system (tower /platter /reels ,) there’s no real need for anything quicker than this as even if your doing changeovers with another machine , this slack is accommodated for by sufficient leader. The nice slow start lets you know alls well , before the main film starts . . . This is all fine when using a 3ph motor controlled by vfd but quite difficult it seems with single ph !

 

OK, if the projector uses an xenon bulb then any soft-start scheme for the motor MUST not feed the bulb power supply also. In an old GE hobby circuits manual there are soft start circuits shown. So the very fist thing is for the TS to verify that a triac control, such as a triac light dimmer, will start the motor with a ramp-up, as desired. If not, then an additional scheme will be required.
Better to know what works before building it.

 

Fairchild has a AC motor Ramp up start circuit in App note AN-3006 (fig3).