Hello!
I have a question about the open collector output to push-pull output converter that I put together. In the attachment you can find the schematic.
In my case inputs and outputs Vcc are both 24 V DC. Outputs are meant to be connected to a PLC input. The circuit actually works fine, but at 24 V supply voltage I get approximately 21,2 V at the output, which is more than enough to activate the PLC input. But because of that there is about 2,8 V drop on the push-pull. I have measured the current and PLC input sinks about 8 mA, so the power dissipation on the push-pull ic should be fine.
I used push pull because I had troubles in the past using pull up resistor, because PLC was sinking to much current. When I was doing that I was using counter module, which probably draws even more current.
I wonder if there is something that I should be concerned about?
Thank you very much in advance.
I have a question about the open collector output to push-pull output converter that I put together. In the attachment you can find the schematic.
In my case inputs and outputs Vcc are both 24 V DC. Outputs are meant to be connected to a PLC input. The circuit actually works fine, but at 24 V supply voltage I get approximately 21,2 V at the output, which is more than enough to activate the PLC input. But because of that there is about 2,8 V drop on the push-pull. I have measured the current and PLC input sinks about 8 mA, so the power dissipation on the push-pull ic should be fine.
I used push pull because I had troubles in the past using pull up resistor, because PLC was sinking to much current. When I was doing that I was using counter module, which probably draws even more current.
I wonder if there is something that I should be concerned about?
Thank you very much in advance.
Attachments
-
14.5 KB Views: 76