View attachment 139717
Hi all

This is the latest schematic which is working fine to run the motor. I have noticed that it consumes 30mA when there is no pulse (20mA for the motor). There shouldn't be any current draw when there is no pulse. Could anyone suggest me please with the modifications I can do that there is no current consumption if there is no pulse?

Well, this is all brand new to me, but based on some recent reading, it seems that stepper motors draw current all the time, and may actually draw the most current when standing still! It looks like some stepper drivers include optional controls to mitigate that wasted energy:

http://www.motioncontroltips.com/faq-stepper-drive-idle-current-reduction-help/

 

View attachment 139717
Hi all

This is the latest schematic which is working fine to run the motor. I have noticed that it consumes 30mA when there is no pulse (20mA for the motor). There shouldn't be any current draw when there is no pulse. Could anyone suggest me please with the modifications I can do that there is no current consumption if there is no pulse?

How do you have three inputs on the inverter?

If you are using three of the four inverters on the chip in parallel, the one connected to the capacitor and diode is latching up. Once the input is high, it will never go low. There is no path to ground- the capacitor cannot discharge.

That inverter's output (low) is essentially sinking the high outputs of the other inverters in parallel (which would be high output.

It is likely hot. And likely your 30mA of loss.

 

How do you have three inputs on the inverter?

If you are using three of the four inverters on the chip in parallel, the one connected to the capacitor and diode is latching up. Once the input is high, it will never go low. There is no path to ground- the capacitor cannot discharge.

That inverter's output (low) is essentially sinking the high outputs of the other inverters in parallel (which would be high output.

It is likely hot. And likely your 30mA of loss.

Sorry I have made a mistake in the schematic. The diode and the capacitor connected to the Vcc of the inverter. Only one input (5V inverted pulse) from the voltage divider goes into the input of the inverter. Other inputs I have grounded them. Is that makes sense? Is that still going to be a problem for 30mA loss?

 

Well, this is all brand new to me, but based on some recent reading, it seems that stepper motors draw current all the time, and may actually draw the most current when standing still! It looks like some stepper drivers include optional controls to mitigate that wasted energy:

http://www.motioncontroltips.com/faq-stepper-drive-idle-current-reduction-help/

Thank you