1

I searched around the forum and found this post: Analog voltage level conversion (level shift)

I built a dinamic motion seat with an Arduino, H-Bridge and 2 wiper motors. The wiper motors are acting like a servo because I mounted a potentiometer to the motor output shaft.

Now my motors will turn only about 180° which will result in an analog voltage from 1.6V to 3.5 Volt.

I've built this circuit:

enter image description here

on a little PCB like this:

enter image description here

From my understanding I can use the bottom potentiometer to set offset voltage 1.6V then move the pot to the maximum position and set the Vout with the upper pot to 5V.

Now the output should be 0-5V at 180° pot movement. I use LM324n and 10k pots. Now the problem is that there is no amplification. I only can lower the voltage at Vout but max is 1.6V too.

Maybe my PCB is built wrong but I've checked it many times. Or did I understand something wrong and this is impossible?

Community
  • 1
Thomas
  • 11
  • 2
  • 1
    You should understand that this is an inverting amplifier configuration, so a high voltage input will give you a low voltage output. Also, with a supply voltage of 5V the LM324 may not give you anything greater than 3.5V on the output. – Joe Hass Nov 27 '13 at 17:31
  • Thanks for your answer. In the Datasheet Supplyvoltage max. is 16V. Its no problem for me to add 12V as supply Voltage, can this solve my problem?. Or is there another soltion for my problem. Because at the moment im using software limit to the pot position and this will let me loose some reachable positions. – Thomas Nov 27 '13 at 17:39

0 Answers0