How to understand the clamp circuit

bigbat

How to understand the clamp circuit [Copy link]

 

This is a simulated clamp circuit experiment. When the "internal resistance" is not set for the signal source, the output voltage of PR1 follows the voltage of V2.

After adding the internal resistance, the voltage is equivalent to a current source. The 12V above is also a current source. It is easy to analyze without a diode. How to analyze with a diode

maychang

"This is a simulated clamp circuit experiment"

Why don’t you continue studying the relationship between transformers and inductors?

maychang

"The voltage is equivalent to a current source after adding internal resistance"

Who said that?

Adding internal resistance to a voltage source is equivalent to connecting a resistor in parallel to a current source, but it cannot be said that "voltage is equivalent to a current source after adding internal resistance."

maychang

"It's easy to analyze without a diode, but how to analyze with a diode?"

The analysis is the same with and without a diode, but since a diode is not a linear element, the calculation is much more complicated than for a linear element.

se7ens

I don't understand, what is the function of your clamp circuit?

bigbat

This is the analog design of the schematic diagram left by the original project. The function of this circuit is to prevent the voltage at point A from being zero when V2 fails (V2 is a DAC output chip, and the voltage applied follows 0~5V). That is, the circuit needs to maintain a voltage of 1.5V.

But I always felt something was wrong, so I wanted to simulate it, but found that it didn't seem to work, and the voltage output couldn't reach 5V.

jimtien

Can clamping be done without capacitors?

bigbat

My analysis is as follows:

The current at point A has four paths, but R3 and R4 can be combined into one circuit, as shown in the figure on the right.

bigbat

jimtien posted on 2022-5-19 15:17 Can clamping be done without capacitors?

Clamping without capacitor

jimtien

This is not called clamping, but addition.

vincentc543

R1 has no series capacitor, how to clamp the AC?? Someone above said this is like an addition circuit...