Hi
I have a small stepper motor for which I am trying to build a controller. I have constructed various separate mini circuits that will be assembled for the final project and all have worked except for my memory portion. I am using a 555 timer for the pulse to clock a CD4042BE quad clocked d latch. First off, it should be obvious that I don't really have any idea what I am doing, I usually just play around while learning (and usually buying new parts), I don't even know if the final assembly will work together. The timer uses a capacitor with a fixed charge resistor and an adjustable discharge resistor to hopefully allow speed control of the motor. Anyway, the part that is giving me problems is the clocked d latch. I have gone through the basics of how and why it works but cannot get it to clock and latch. Possibly I have damaged this device. I have Vdd (5V+)and Vss and am getting 5V out of Q with nothing at D (that is, no wires attached). If I apply a signal (I used 5V) to D nothing changes which is backwards from the tutorials I have read. If I apply ground to D I get a switch of Q and Qbar but if I apply a signal to the clock (again 5V and also tried ground) it will not stay latched, the outputs stay switched for about 5 seconds then switch back. So, basically after all this explanation, my question is: What is meant by a signal to clock? (i.e. + or - voltage, current limits, ???) And is there a requirement for pulse length? (the data sheet indicates that there is not) I need to save the last state of the motor to allow for selection of the next stator winding otherwise I would not mess with this except to learn how it works for fun. Thanks for help with my errors.
I have a small stepper motor for which I am trying to build a controller. I have constructed various separate mini circuits that will be assembled for the final project and all have worked except for my memory portion. I am using a 555 timer for the pulse to clock a CD4042BE quad clocked d latch. First off, it should be obvious that I don't really have any idea what I am doing, I usually just play around while learning (and usually buying new parts), I don't even know if the final assembly will work together. The timer uses a capacitor with a fixed charge resistor and an adjustable discharge resistor to hopefully allow speed control of the motor. Anyway, the part that is giving me problems is the clocked d latch. I have gone through the basics of how and why it works but cannot get it to clock and latch. Possibly I have damaged this device. I have Vdd (5V+)and Vss and am getting 5V out of Q with nothing at D (that is, no wires attached). If I apply a signal (I used 5V) to D nothing changes which is backwards from the tutorials I have read. If I apply ground to D I get a switch of Q and Qbar but if I apply a signal to the clock (again 5V and also tried ground) it will not stay latched, the outputs stay switched for about 5 seconds then switch back. So, basically after all this explanation, my question is: What is meant by a signal to clock? (i.e. + or - voltage, current limits, ???) And is there a requirement for pulse length? (the data sheet indicates that there is not) I need to save the last state of the motor to allow for selection of the next stator winding otherwise I would not mess with this except to learn how it works for fun. Thanks for help with my errors.