- #1
FrankJ777 said:Is it possible to power the op amp in this diagram in this manner if it requires +18V and -18V?
This doesn't seem valid to me, but I'm not sure why it's not exactly.
Thanks
Yep. Here a Texas Instruments Application Report with a collection of Single-Supply Op-Amp Circuits.Averagesupernova said:The schematic in post #4 is definitely workable. I have used it or something similar many times.
yungman said:That's what I have been doing in the last few months! I am designing electronics inside guitar and guitar effect pedals.
Jony130 said:Well these resistor create a circuit that is called "virtual ground".
Every real life "active device" to work properly as an amplifier supplied from a single source need proper bias circuit.
When you use BJT as a CE amplifier, you use a voltage divider to bias the active device somewhere in the "linear region".
In case of single supply op amp you have to do the same think. You need to bias the op amp somewhere in the middle of his "linear region". And this resistor provide proper DC bias for Op amp.
rbj said:sounds like a good gig.
do you or have you worked on any digital effects devices?
can you tell us what some of these stomp boxes are?
L8r,
r b-j
jegues said:I am familiar with the need for biasing networks when working with active amplifiers, I'm just not seeing how the resistors in the original post provide any type of biasing at all.
Regardless of the value of R1, the terminals labeled Vcc and Vee are going to sit at the voltages on positive and negative terminals of the battery. How is that providing any form of biasing at all?
The only thing I can see is that the resistors provide one with a point to ground the circuit.
jegues said:I am familiar with the need for biasing networks when working with active amplifiers, I'm just not seeing how the resistors in the original post provide any type of biasing at all.
Regardless of the value of R1, the terminals labeled Vcc and Vee are going to sit at the voltages on positive and negative terminals of the battery. How is that providing any form of biasing at all?
The only thing I can see is that the resistors provide one with a point to ground the circuit.
vk6kro said:The original circuit was not meant to be complete.
Op amps typically require a dual power supply, with a positive and negative voltage source. However, some op amps can also be powered from a single supply by using a voltage divider circuit to create a virtual ground.
Using a single power supply can simplify the circuit design and reduce component costs. It also allows for easier integration with other single supply systems.
The voltage range for a single supply op amp can vary, but it is typically between 3-30V. It is important to check the datasheet for the specific op amp being used.
In some cases, a single supply op amp can be used in place of a dual supply op amp by modifying the circuit design. However, it is important to consider the specific requirements and limitations of the application.
One limitation of using a single supply op amp is that the output voltage swing may be limited compared to a dual supply op amp. Additionally, the virtual ground created by the voltage divider circuit may not be as stable as a true ground, leading to potential noise or stability issues. It is important to carefully consider these limitations when choosing a single supply op amp for a specific application.