Motor speed control Vs by-pass

[Old Grey]

I seam to notice that people are favouring motor speed control over the simple air by-pass bled-off system that was popular 2007.

Are there any down falls to using a simple valve type system on the side of a bench.

[Brucepts]

1) Better static pressure control
2) Less wear and tear on motors from running full out and throttling the airflow under full power, less heat, less noise
3) Ability to use the automatic depression control

The bleed valve method works it's just been felt the motor speed control has more advantages. Most times the motors using the speed control are hardly running 1/2 to 3/4 speed, with the bleed you would be running some or all of them at full power and make them work against the bleed restriction.

Having used both now I would never go back to the bleed, on my flowbench I'm running 2 motors on control and switch other motors on as required. Since building a full motor control flowbench for a customer and using it for a little in my shop I'm keen on swapping the PTS Prototype flowbench over to that setup, just been to lazy to do it and can't really do without my flowbench for the time it would take for me to swap over the way I would want it to be done.

[Hotz]

Studies I have better use the speed control type PTS.
More economy and higher accuracy over time to use automatic control.

[Tony]

Less heat, noise and power consumption, and the motors should last longer.
Its a funny thing, but when you are making some noise yourself it doesn't seem all that objectionable, but for neighbors and other family members it can become an issue over time.

Automatic closed loop pressure control will hold the test pressure rock steady despite jumps in mains voltage, and eliminate slow pressure creep caused by motor temperature variations with varying air loads.

Controlling motor speed electronically is by far the better system.
Nobody ever goes back to using a flow valve after they have used a motor speed controlled bench.