Substituting a digital pot for a mechanical pot in an AC voltage control circuit

Look at the datasheet, here:

The maximum input voltage is less than a volt above Vcc, which is also limited to 5V. The pot, on the other hand, doesn't have the same restriction.

I could not find the ac voltage controller you indicated on the radio shack site, so I can't comment on whether this should work or not, but I'd keep the 5V restriction in mind.

Regards, Bob Monsen

The datasheet states that the voltages on the resistor terminals must be between -5V and +5V - if any voltages are outside that range, you will probably destroy the part.

You can get the full datasheet from

Is there any AC motor controller that is computer controlled? (RS-232/ USB or TTL)

I guess the Maxim/Dallas parts won't work. I see that even AD digipots wont work (some will work with 10-15VAC, but not higher)

--- Did you post a schematic of the radio shack circuitry? No.

Is it available on their web site? No.

Are we mind readers? No.

So how on earth do you expect anyone to give you any sort of meaningful help if you don't even know how to ask a proper question and tell us what it is you're up to?

Hmmm... I see you're posting form Google Groups, so never mind... that explains it.

JF

What kind of motor is it?

/bob

The motor is an AC motor. I do not know the manufacturer of it. However I have the following specs/attributes which may help in choosing the controller for it.

single phase AC, 115VAC

The radio shack thingy controls the speed properly, right?

One possibility would be a motorized pot.

This one probably won't work, but one of these might:

The other possibility is to measure the voltage that was across the pot before you cut it out. If you post that information, it may well be that someone can design a circuit that would let you control the control.

Regards, Bob Monsen

Bob,

Thanks for the idea of the motorized pot. I should have thought of that one. I will look to see if I can find a 250K Ohm motorized pot.

As far as the voltage across the pot, I would have to measure it when in operation. I can imagine that it runs from 0 to about