About Servo Motors

[gokhan karaova]

Hello,

I have to run servo motor by different dc inputs but I am only allowed to use analog components. Do you have any recommedns how to crete this circuit?

 

[Gryd3]

Hello,

I have to run servo motor by different dc inputs but I am only allowed to use analog components. Do you have any recommedns how to crete this circuit?

Depends what you need to do with it... a 555 timer can control a servo.
Is this homework? What is your goal for this?

 

[gokhan karaova]

Its my term project and I am only allowed to use transistors, opamps , resistor. capacitor, inductor and ldr. I have to send a signal to servo motor so as in one condition it stays closed and in another condition it opens for a while. Both voltages that reaches to servo are in DC. I think, I have to construct a circuit that transform the signal from DC to pulse with PWM. I found couple of ways but both of them are very complicated and messy. I am not very familar with PWM and maybe there is a way to make it easy. Any recommends?

 

[Bluejets]

As Gryd3 says, 555 timer and a couple of switches.
mmm...no switches or linear ic's allowed.
Still, ldr could make the timing change and from memory one can get a 741 or similar to do the timing.....just not as simple and simple is another required parameter.

 

[Colin Mitchell]

It's far too hard to control a servo with individual components.
The input timing signal is very complex.
Your teacher obviously doesn't have a clue about electronics.
A 555 is analogue and is just two op amps and an amplifier.

 

[GPG]

The input timing signal is very complex.

Standard input for RC servos is1mS to 2ms pulse 1.5 ms being centre. The spacing between pulses is not very critical. Not very complex at all
https://en.wikipedia.org/wiki/Servo_control
OP: you can make an oscillator from an op-amp and control the width of the pulse. That's your start. A big hint, it requires both positive and negative feedback. If you want to impress the tutor use a couple of transistors in an astable multivibrator.