Originally Posted by ignisuti

I purchased a couple quadrature incremental rotatory encoders (ACZ16NBR1E-20KQA1-12C) and they're not responding as I had expected.

To test them, I connected phases A & B to 5V through LEDs and Common to ground. Yes, I know it'll damage my LEDs, but I just wanted to see the encoder work for the first time. I expected to see each LED light up 2 times for every 4 positions of the dial.

Instead, I see very erratic behavior. Typically the LED only lights up half-way through a position change. Sometimes the LED will stay on after I reached a position, but it occurs much less often than 50% of the time.

This is my first encoder experience. Please help!

hi,
Have you a sketch showing how you have wired the encoder.?

Using a 5v supply, you MUST use a series resistor to limit the current thru the LED and switch contacts!

EDIT: look at this image

I've just connected them like this as a temporary setup so that I can verify the operation of the rotary encoder. 5V through the LED will GREATLY reduce the LEDs life, but it should last long enough for me to finish this quick test. As for the contacts of the switch, it should handle 5V just fine.

I don't have a schematic, but it's simple enough to explain. Pins A & B are connected to 5V through an LED and the common pin on the encoder is connected to ground. So as the quadrature encoder moves 4 positions, I expect to see each LED light up twice.

EDIT,
Eric, I see the diagram you posted. My setup is just like that minus the resistors.

Originally Posted by ignisuti

I've just connected them like this as a temporary setup so that I can verify the operation of the rotary encoder. 5V through the LED will GREATLY reduce the LEDs life, but it should last long enough for me to finish this quick test. As for the contacts of the switch, it should handle 5V just fine.

I don't have a schematic, but it's simple enough to explain. Pins A & B are connected to 5V through an LED and the common pin on the encoder is connected to ground. So as the quadrature encoder moves 4 positions, I expect to see each LED light up twice.

hi,
OK.
Its NOT the 5V thats concerns me, its the current thru the encoder contacts!

Originally Posted by ignisuti

So, are you saying that my setup is invalid for verifying that the rotary encoder works the way I expect it to? If so, please explain.

Have you looked at that image I posted.?

The switching pattern of the encoder is taken from the datasheet of the type you have posted. I added the small diagram how it should be connected.

Is your circuit the same as the image, also be sure that you have correctly identified the 'C' pin.

Originally Posted by ignisuti

Yes, my setup is the same minus the resistors. I would have to disagree if you argue that the resistors are critical for me to see what I'm trying to see.
I'll have to test and report back...

If you read my posts I have not said that the fact you are not using a current limiting resistor will stop seeing what you are trying to see.!

What I keep repeating is, without a limiting resistor and the fact that you are using a 5v supply, if an LED fails short circuit you will most likely damage the encoder contacts.

I am puzzled why you dont want to fit a simple resistor in series with each LED, say 470R.

Perhaps some other member will help you with this problem.

I've always wondered why some folks just don't like resistors.

Originally Posted by ignisuti

Resistors are fine. I just made the decision that I'd rather throw away $0.20 worth of LED's versus spend the extra 30 seconds to add resistors for my quick one-time test.

I don't see how 5V would damage these contacts. They're rated for 5V.

Your NOT listening, its NOT the voltage thats the problem its the possible high current!

There probably not meant handle more then 10ma of power
He just knocking off part of his 100,000 cycles maybe have 10 left.
Rated for 5V don't mean it can can sink a amp

hi,
Look at this image to see the sequence you should observe.

The design of the quadrature signal phasing is so that its possible to determine which way the shaft is being turned and by how many indentations. [steps]

Quadrature of the two signals means they are shifted in phase by 90deg relative to each other.

The 'detent' stability points on the signals are where the mechanical indents in the switch mechanism are located,, ie: at rest.

A point to remember is that if switch contacts are subject to switching currents higher than the maximum rated value the contacts can be damaged.
This damage will cause intermittent closures creating multiple signals to the external equipment.