Hi all,
We know that a Function Generator circuit has Thevenin equivalent and the whole circuit is equivalent to a Voltage source in series with a 50 ohm resistor (internal impedance). That is why the output of the Function Generator depends on the load resistor we use (1Mohm load yields a 2 times bigger voltage compared to a 50 ohm) and this is because of the voltage that is divided by two Load and Internal resistors. However, we do not see such a variation in the output voltage of a power supply! In other words the output of the power supply is always 12 V (or whatever) no matter if the load resistance is 1Mohm or 50ohm. This is a little confusing for me. What is the main difference between FG and PS circuits?
Why can’t we find a Thevenin equivalent for a PS and do the same math (voltage divider) as for FG?
I read on the web that PS is a POWER SOURCE (fits the name actually) and FG is VOLTAGE SOURCE but I do not know what it means. Can anyone help me to understand this?
Thank you,
S
We know that a Function Generator circuit has Thevenin equivalent and the whole circuit is equivalent to a Voltage source in series with a 50 ohm resistor (internal impedance). That is why the output of the Function Generator depends on the load resistor we use (1Mohm load yields a 2 times bigger voltage compared to a 50 ohm) and this is because of the voltage that is divided by two Load and Internal resistors. However, we do not see such a variation in the output voltage of a power supply! In other words the output of the power supply is always 12 V (or whatever) no matter if the load resistance is 1Mohm or 50ohm. This is a little confusing for me. What is the main difference between FG and PS circuits?
Why can’t we find a Thevenin equivalent for a PS and do the same math (voltage divider) as for FG?
I read on the web that PS is a POWER SOURCE (fits the name actually) and FG is VOLTAGE SOURCE but I do not know what it means. Can anyone help me to understand this?
Thank you,
S