single supply amp

[nos_joel]

Hello everyone,
I am trying to desing a single supply current amplifier to drive a motor. The fact is that I don't want to use a H bridge. I have been using a AB class amp, but it requires two bias. Could someone help me?.
Regards

 

[Torben]

Why don't you want to use an H bridge?


Torben

 

[Willbe]

Hello everyone,
I am trying to desing a single supply current amplifier to drive a motor. The fact is that I don't want to use a H bridge. I have been using a AB class amp,
78% efficient
but it requires two bias.
You mean plus and minus supplies?

Use an emitter follower, 50% efficient?

You need reversing?
What steady-state voltage & current into the motor?

 

[Hero999]

Why don't you want to use an h-bridge?

You'll need a dual power supply if don't use one and still want to reverse the motor. If you don't want to reverse the motor then fine don't use an h-bridge.

Why are you bothering with class AB, class B will do, although it's a pretty rubbish way of controlling a motor the torque will be very low at low speeds, use PWM and and h-bridge for best results.

 

[nos_joel]

thanks for replaying,
Well I have never used an H bridge, but I have heard a lot about them and know about their function. I am trying to move the motor on both directions. If I want the motor to turn on clockwise direction I should enable two transistors, and if want to turn on the other direction should enable the other two transistors.
I will control a servo motor subtracting the reference and the feedback signal which as a result will give both + and - voltage. The question is, how do I control the servo using the H bridge?

 

[blueroomelectronics]

A hobby servo uses a digital signal.

 

[Willbe]

If I want the motor to turn on clockwise direction I should enable two transistors, and if want to turn on the other direction should enable the other two transistors.

Seems like you are describing an H-bridge.
https://en.wikipedia.org/wiki/H-bridge

 

[Nigel Goodwin]

It's quite simple, for a single supply you need an H-Bridge, for a split supply you only need half the H.