Basically the idea is to drive the winding with a much higher voltage, this decreases the rise time to charge the winding inductance. Also, if you have the gate floating, the state of the mosfet could be undefined. Ubergeek63 Well-Known Member Jun 7, If I reduce the step time from uS to uS, the motor stalls. He who knows and knows he knows: Cheers for your help.

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Part and Inventory Search. Using the transistor to drive the gate with higher voltage solved the problem.

Who can tell me what should I improve i my schematic?

Stepper Motor speed Control

CT measuring circuit with PIC 3. At 21 May5: Like I said to Phillpill – I did a “quick” simulation. Media New media New comments Search media. All the stuff I sell on the site is stuff I have in stock – I’ve given up ordering in stuff for people as it tends to hang around and not get sold. The problem with thouse drivers and using just N channel MOSFETs is that those drivers use a charge pump to generate the high gate voltage.


I’m thinking I will have the voltage supplied to the opamps and the main Vcc at 18V or so. Any program for control the speed of the stepper motor?

Stepper Motor Driver Problem

I had a look into using just N channel with a driver, but jrf540 to the conclusion that it’s not suitable for my application due to the switching losses. Quick Links Categories Recent Discussions. This is the power supply of the motor. That’s impressive about the sherline mill. Using a higher voltage makes the current rising faster.

Stepper Motor Driver Problem — Parallax Forums

At 9 March Indeed, more and more FETs availablefor 3. Now you want to put current through a coil.

Thanks again At 17 October9: This is why you saw such a dramatic increase in current mltor you moved from 6V to 12V. Chagrin Faraday Member Posts: Did you see an application note of AVR or others.

From each mosfet, there is a pin output, a total of 4 outputs comes from the circuit. The IRL is a logic level FET and putting 5 Volt on the gate should be enough to open it up, albeit that it has a drain source resistance of less than one ohm, though that depends a bit on the current and the temperature. Should I connect a L or another IC. When I apply the 12V directly to the coil, it pulls about 1.


I fount documentations but in chineese so I coudn’t get the informations that I want. The standard mosfet IRF series etc is designed to run from 10V. Not an ideal choice, but a good one.

It may go clockwise and counterclockwise with no certain order. A schematic is attached of a circuit I designed recently, but haven’t built yet.

Motir should have posted the LTSpice simulation file as part of the. Stepper Motor speed Control The way to slow down the stepper speed is the same used to increase it. I am right now not using any PWM inputs to H bridges.

As the current starts to flow, the drop across the shunt increases, thereby making the opamp decreases the voltage output, thereby reducing the steppeg across the winding, thereby slowing the current rise, etc.