Help with encoder connected to logic circuit

Hi,

I know this might not be the right place to ask this but I'm kinda stuck and haven't come across anywhere more likely yet.

Basically what I'm trying to do is time the acceleration of an encoder. I have a PCI card in my Windows PC but it's not a counter card so isn't capable of the timing I need. It has a couple of fast counters and some digital inputs and outputs.

The encoder is a Hengstler RI38 with A,B and Z outputs, these are pushpull type. So 50 times a revolution the encoder sends a pulse on the A line. What I want to do is feed this A input into the CLOCK side of a JK flipflop with the J and K inputs tied. The result being that when the encoder sends its first pulse the output of the JK will be 1 and will stay 1 until the next pulse when it will toggle to 0 and so on.

I've tested my JK flipflop with a slow 555 timer pulse and what I'm looking for works fine, but when I connect in the encoder things start to go a bit mad. Spinning the encoder is causing the flipflop to toggle without me even connecting the encoder to the flipflop, it seems to be coming through ground or +5V. Basically I think I have some sort of noise issue or I have completely misunderstood how to connect the encoder to a TTL circuit. With a probe on the 555 timer I see a LOW signal as 0V and HIGH as about 5V, but from the encoder a LOW seems to be about 0.6V and a high somewhere over 4V.

Does anybody know what I'm doing wrong here? Do I need pull up or pull down resistors? This kind of thing isn't my speciality so I imagine one of you gurus will look at it and wonder why the hell I forgot to connect component X to connection Y .


Any and ALL help much appreciated!

s7 200

Please help;

I am programing a roll forming machine, after dividing and subtracting process. it was the zero point in (-675)reading by vd1, tell me please how i can use the vd1.

a.aladawi said:

I am programing a roll forming machine, after dividing and subtracting process. it was the zero point in (-675)reading by vd1, tell me please how i can use the vd1.

Click to expand...

HI you need to create a New Thread - This is posted in an existing post

Zenith63 said:

Hi,

I know this might not be the right place to ask this but I'm kinda stuck and haven't come across anywhere more likely yet.

Basically what I'm trying to do is time the acceleration of an encoder. I have a PCI card in my Windows PC but it's not a counter card so isn't capable of the timing I need. It has a couple of fast counters and some digital inputs and outputs.

The encoder is a Hengstler RI38 with A,B and Z outputs, these are pushpull type. So 50 times a revolution the encoder sends a pulse on the A line. What I want to do is feed this A input into the CLOCK side of a JK flipflop with the J and K inputs tied. The result being that when the encoder sends its first pulse the output of the JK will be 1 and will stay 1 until the next pulse when it will toggle to 0 and so on.

I've tested my JK flipflop with a slow 555 timer pulse and what I'm looking for works fine, but when I connect in the encoder things start to go a bit mad. Spinning the encoder is causing the flipflop to toggle without me even connecting the encoder to the flipflop, it seems to be coming through ground or +5V. Basically I think I have some sort of noise issue or I have completely misunderstood how to connect the encoder to a TTL circuit. With a probe on the 555 timer I see a LOW signal as 0V and HIGH as about 5V, but from the encoder a LOW seems to be about 0.6V and a high somewhere over 4V.

Does anybody know what I'm doing wrong here? Do I need pull up or pull down resistors? This kind of thing isn't my speciality so I imagine one of you gurus will look at it and wonder why the hell I forgot to connect component X to connection Y .


Any and ALL help much appreciated!

Click to expand...

Not sure exactly how you have connected this.
do you have a Breadboard with I.C's on it.

The PUSHPULL type encoder needs to know what voltage to switch.
So - Yes you need either Pull Up or Pull Down resistor depending on your logic.

If you have an I.C. Breadboard then get a decade counter Chip
designed specifically to count.

Thanks iant, I discovered that after a few days messing around. 3 years late with the reply but appreciated!

Sorry I had seen the other post - sent a msg to him an neglected to realise the date of your post

I was off the site for those three years or I would have helped then

Have a drink on me