Hello,
Apologies if I've placed this in the wrong section.
I'm currently working on a university project to build a pulse extender with the ability to alter the output using a programmable potentiometer board. (RS232 - 8 Channel board from National Control Devices).
All components apart from the board are being powered using a 5v supply, with the board using a 12v supply. The input pulse is a 5v pulse of 350ns duration.
My minimum output value is around 515ns output with 10nF and 10Ω on the timing circuit. However when I put the potentiometer up to its maximum value of 50kΩ my output pulse only reaches 60us. By my calculations this should exceed that value all the way up to 300us+. The output signal is also very jittery, going between roughly 58us-63us. My aim is to reach a maximum value of 100us whilst keeping the minimum 515ns intact.
I've placed a 10Ω resistor in series with the potentiometer as the board does not seem to function unless this is in place.
Any advice you can give would be appreciated, have I just made a silly calculation error and that is the actual value? Am I missing something else?
Thanks!