speed control fro a dc motor(24V) with an inner current control loop

[jason]

hi, now i am doing a project the used to control the speed of a dc motor with a inner current control loop. the dc motor that i am using is 24v, and i am using SG3525 and PWM which used to generated pulse signal to control a H-bridge (LMD 18000). the motor with an encoder that will produce one pulse per revolution, so the problem is how can i get an analog signal from the encoder. and any idea to connect between SG3525 with LMD 18000? Thanks.

 

[Grossel]

To get voltage from pulse, you must do this:
1 - The pulse should activate a monostable flip-flop (mfp). This would provide an output with same pulse width, but variable duration between the pulses.
2 - This signal from the mfp should be conected to a RC network to get a smooth DC-voltage.

 

[fsmyth]

Feedback example with discretes:
H-Bridge Motor Driver Examples
D.C. driver with SG3525:
D.C. Motor Drivers (2)

 

[manymany]

**broken link removed**

Hi, I am doing a velocity controller for a printer dc motor. But because I am not a control student, I seek your help in understanding the feedback loop diagram.

I've attained the System's transfer function which is "Velocity over Voltage" from open loop. Which means System output or measured output is velocity as read by the encoder. So the transfer function of the controller is "Voltage over Velocity". Why is the transfer function of the controller in the form of "input over output" instead of "Velocity over voltage"?

Thanks.

 

[ccurtis]

I've attained the System's transfer function which is "Velocity over Voltage" from open loop. Which means System output or measured output is velocity as read by the encoder. So the transfer function of the controller is "Voltage over Velocity". Why is the transfer function of the controller in the form of "input over output" instead of "Velocity over voltage"?

Whether the transfer function is specified as in/out (or out/in) is not important as a practical matter. Mathematically, A/B can be expressed as the reciprocal of B/A, or 1÷(B/A).