How to control DC motor as car engine???

[anip]

i have a problem to control DC motor. In this case i want to manipulate DC motor as car engine. That mean it have several button to increase the speed of motor and to reverse the rotation of the motor. Anyway I was using microprocessor 8085 to manipulate it. Can anyone give an idea to make assembly language and circuit to design it????

 

[(*steve*)]

car as in model car, or as in electric vehicle?

There are specialised devices that have interfaces which can be connected to an accelerator pedal. If you want to build it yourself you'll be doing a seriously high power mosfet bridge with a PWM controller.

Seriously high power means that you need to know what you're doing or you will turn expensive mosfets into smoke.

Can you enlighten us as to the voltage rating for the motor, your batteries, and the DC resistance of the motor, and its rated power?

 

[anip]

actually I want to used 5volt voltage.....by using assembly code and keypad, I can manipulate that DC motor very well....although to increase the speed or to reverse the rotation of motor..

 

[(*steve*)]

Tell me again what you want to use this motor for?

Anyway. To control the speed and direction, what you need is an H Bridge. Provide PWM control to control the speed, and turn on pairs of devices as required to change the direction.

Googling H-Bridge should give you plenty to start off with and come back with any other questions you may have.

Controlling a low voltage, low power motor will not be too difficult. However, I'm not certain that this is what you have in mind.

 

[tgil]

First of all, your life will be much more difficult if you use assembly rather than C. There are plenty of great, free C compilers (e.g., gcc, sdcc).

As for the motor control, you will want an H-bridge like mentioned. I recommend finding one that is designed for controlling a motor with digital circuitry. One example of such a device is the SI9986DY-T1-E3 from Vishay.