How the dc motor operates in the circuit

how the dc motor is operates and what are the their current and voltage wave form at the output.

It’s not going to work at all, since R1 will draw 1A from the regulator, which is all it can supply.

Nearly the same as:

This is mostly a forum about the KiCad software itself, and not about electronics. I don’t want to scare you away, but there are better sites for learning the basics of electronics.

then how can see the motor current.

Put the resistor in series with the motor.
And, 5Ω is way too big. Try .1Ω or less.

“.tran …” at the schematic suggests me that OP wants to use SPICE to see that current and not oscilloscope so resistor should be not needed.
I have never tried to use SPICE from KiCad. I use PSPICE that I got demo (limited version) in previous century. There I can see at the output graph current into any pin at schematic.
Can’t KiCad SPICE simulator show it?

Looks dangerous to me.
Grounded AC???

I think that’s needed for the spice simulation. It does not accept floating circuits.

yes. i have use the spice model for thar motor and transformer and voltage regulator.

if we take the resistor in series the output of the current wave form to get the ripples

NO. for see the motor current at the output . we take the resistor in parallel to the circuit.

Ahh, no, that is a shunt path.

Euhm, no, Piotr ws right here. The usual way to measure current through a wire is to use a shunt resistor that produces a small voltage drop that is proportional with the current through the wire.

I’m not sure what you mean with these “ripples”.

3Dogs is also right with the load limit of an LM7805. Putting a 5 Ohm resistor parallel to the motor would just be big waste of the power. It’s also normal for a DC motor to have some ripple in the current when the commutator moves from one position to the next. I don’t know if the model of your motor has that in it’s model though. Interpreting spice simulations and knowing their limitations is … a separate topic.

This sounds like a homework assignment we are doing for you.


Sounds like crap of the year.
If you connect resistor in parallel to something. The current in resistor depend only on voltage between its ends (Ohm law). Looking at current in resistor (or voltage on it) you can know the current generated by motor (rotating by momentum or mechanically driven from the outside) only if there is nothing else in that circuit (they are not connected to 7805 in your case).

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Being more of an LTspice fan versus NGspice, I started a Motor circuit in LTspice with typical Resistance and Inductance (too easy) but, I wanted a more detailed real-world analysis and found several.

I like this YouTube video and the principle’s will apply to NGspice modeling

A simplified approach in Kicad/NGspice would be to start with R and L and a simplified Voltage source, from there you can add BackEMF…etc

can you explain briefly about how the dc motor is operates.

Sorry, but we again have to draw a line somewhere (not in a schematic, but in this forum). This is not a place for generic electronics questions, but targeted towards questions and talk about KiCad software.