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I am wanting an op amp that can act as a voltage follower. Essentially the project is speed control of a motor and since PWM is being used, the following circuit was going to be implemented: Essentially just a RC filter to get the analogue signal, then a voltage follower so that the motor can draw the required current it needs since the arduino can only output say 20mA. enter image description here (Ignore the output 1k resistor)

As i do not know that much about opamps and what to look for for when choosing them, i was wondering if i could get some suggestions or even possibly a standard op amp that will work?

The supply to the op amp will be 5V, and preferably a component from Jaycar due to the time limit?

The input voltage to the opamp will be roughly always less then 4.5V The motor roughly draws 0.2 - 0.3A Motor: enter image description here

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    \$\begingroup\$ If you already have a PWM signal, then why not just hook it straight into an H-bridge (very efficient)? Why convert PWM -> Analog -> op-amp (very inefficient)? \$\endgroup\$ – Harry Svensson May 22 at 3:44
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    \$\begingroup\$ Here’s a half bridge tinyurl.com/y4le5a7c. Duplicate this for the other side but with inverted clock (PWM) to get stop at 50% and directional control. Use power transistors \$\endgroup\$ – Sunnyskyguy EE75 May 22 at 5:16
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    \$\begingroup\$ @Student PWM with a 1 second period (=1 Hz) is very low, shouldn't you be in the kHz range? If you use PWM in the kHz range then the motor itself will act as a low pass filter, it already has inductive elements behaving like a low pass filter, also its rotor acts as yet another low pass element. - I know that a guy called "Andy Aka" made a good H-bridge design, this is my attempt at remaking it from memory. If Andy ever sees this... sorry for not making it as good as you did it. Forgive me. \$\endgroup\$ – Harry Svensson May 22 at 5:54
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    \$\begingroup\$ @Student Depending on whatever your load is and the size of the motor, it might be okay, though you'll definitely hear a 400 Hz hum. But then again, there is a motor running, so you're already creating noise, some extra hum shouldn't bother you. Though, I'd try to push that frequency up by a factor of 10 or 100 if I were you. \$\endgroup\$ – Harry Svensson May 22 at 6:02
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    \$\begingroup\$ @Student This is what 400 Hz hum sounds like. This is how an electric motor kinda sounds like. I am implying that you won't be bothered by the 400 Hz hum when you have a motor running. - Using an H-bridge instead of only one mosfet has the strength of allowing the current to flow in low-resistance paths, and that the back-emf gets clamped with yet again, low-resistance components. - But then again, I'm slightly overpendantic, it's obvious that your motor is small, so you shouldn't put too much thought into it. \$\endgroup\$ – Harry Svensson May 22 at 6:23

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