What does Vcc and Vref mean?

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TheMusicStudent

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I'm currently looking at the "Glory Hole" schematic (Attached), trying to simulate it in LTspice. However, there are many connections to either Vcc or Vref. What do these mean?
 

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@TheMusicStudent — Further 101 reading that might be of interest:

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Vref is often used as a kind of ground. Sometimes, but not always, components referenced to Vref can be referenced to ground instead, and sometimes it's better to do so. However knowing when to do so is a dark art and only witches and virgins can tell you.
 
HamishR said:
However knowing when to do so is a dark art and only witches and virgins can tell you.
Click to expand...
Look at how your opamps are connected. If the negative rail (pin 4 on a TL072 or similar) goes to ground, your Vref is going to be half of your positive rail voltage (VCC). If the negative rail is connected to a negative voltage opposite of the positive rail's voltage, i.e. +9V on pin 8 and -9V on pin 4, then your Vref will actually be 0V, or ground.

Vref is still half of the total "swing" between the two rails.

What's halfway between 9 and 0? 4.5

What's halfway between +9 and -9? 0

What's halfway between +18 and -9? +4.5

What's halfway between +15 and -15? 0

There's a rhyme and reason behind it.


*Disclaimer - definitely not a virgin, probably not a witch
 
Last edited:
vigilante398 said:
Look at how your opamps are connected. If the negative rail (pin 4 on a TL072 or similar) goes to ground, your Vref is going to be half of your positive rail voltage (VCC). If the negative rail is connected to a negative voltage, i.e. +9V on pin 8 and -9V on pin 4, then your Vref will actually be 0V, or ground.

Vref is still half of the total "swing" between the two rails.

What's halfway between 9 and 0? 4.5

What's halfway between +9 and -9? 0

What's halfway between +18 and -9? +4.5

What's halfway between +15 and -15? 0

There's a rhyme and reason behind it.


*Disclaimer - definitely not a virgin, probably not a witch
Click to expand...
Very small rocks!
 
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