Exclusive Or Logic

[RB1]

Does any body have a real world example of a motor control circuit that uses "Exclusive Or" logic?

 

[kspifldorf]

Run or Jog. Through a selector switch. one or the other, not both.

 

[mcclary's electrical]

It sounds like fancy wording for a three position H/O/A to me.



or maybe just H/A

 

[kspifldorf]

Yea Forward Or Reverse.

 

[RB1]

"Exclusive Or" would be on when both switches are off. I think.

 

[jumper]

Nope,
2-input Ex-OR Gate
Symbol Truth Table
B A Q
0 0 0
0 1 1
1 0 1
1 1 0
Boolean Expression Q = A ⊕ B Read as A OR B but NOT BOTH gives Q

Then, the logic function implemented by a 2-input Ex-OR is given as "either A OR B but NOT both" will give an output at Q. In general, an Ex-OR gate will give an output value of logic "1" ONLY when there are an ODD number of 1's on the inputs to the gate

 

[jim dungar]

"Exclusive Or" would be on when both switches are off. I think.

Nope,

Exclusive OR is: true with one OR the other but NOT BOTH.

The most common example would be a reversing motor control circuit. A motor can run either forward or reverse but not both ways at once. Therefore the control circuit must prevent both from happening at once, which is usually accomplished through interlocks (either mechanical or electrical or even both types).

 

[kspifldorf]

"Exclusive Or" would be on when both switches are off. I think.

You are talking real world right. That could also be a three-way lighting circuit,:grin:

 

[LarryFine]

Think of simple switch circuits as logic gates. For example:

AND = two (or more) SPST switches in series. Output only with all switches closed.

OR = two (or more) SPST switches in parallel. Output with one or more switches closed.



Your exclusive-OR = a pair of 3-way switches, but marked 'on' and 'off'. Output with one switch 'on', not with both.

 

[KP2]

A simple motor control circuit would be a green pilot light to show that power is on thru a normaly closed contact and a red light to show that a motor is running thru the normaly closed contact of the same relay.