Hi, I’m replacing some “physical” switches with the output of my K8061 board here is a circuit diagram of the original switch set.
Basically pin 3 is the ‘input’ 12v, the On/Off switch acts as a hardware interlock to the other switches as well as outputting 12v on pin 1, the other switches output 12v on pins 4, 5 and 6 respectively …
I presume that I can just connect pin 3 to the Clamp and then pins 1,4,5 and 6 to the outputs of the K8061 board (using a software interlock for 4,5 and 6), plus ensure that they are grounded together
The digital outputs of the K8061 are open collector NPN transistor outputs. When activated (turned ON), the output is pulled down to GND.
This is the internal circuit diagram of the digital output.
In your case you have to use external relays or PNP transistors to invert the signal to get +12V output.
Thanks for the speedy response, could I just inverse the logic in software, i.e. have all outputs activated and deactivate them when I wanted them switched on?
The outputs have only two states either ON (pulled down to GND) or OFF (open).
If you invert the output with an external relay or transistor you can invert the operation in the software to get it operate as you like.
… not that I’m particulally against using transistors (which I’m not, just want to keep the external circuit as simple as possible), could I merely place a resistor between the clamp and the output (obviously the resistor will have to be significantly less than the resistance than the circuitry I’m driving), that way when the port is activated it will pull the output down to 0V and with it deactivated the output will be open and as such the voltage will be 12V
Yes, you can. Indeed, this is an easy solution if the input resistance of the circuitry you are driving is significantly higher than the added pull-up resistor value.
The lowest acceptable value for the pull-up resistor between the CLAMP and the digital output is 12V/0.1A = 120ohms.
