Recent content by kahei

Do you mean that I should first convert the a.c. (e.g. 220V ac) to d.c., then connect it to the oscillator circuit? Would the output of d.c. be too high? Beside, may you please give me some links for me to have some references? Thanks a lot.

I would like to ask how to change the frequency of the ac supply (frequency = 50Hz) to a ac with a very high frequency. Does anyone suggest any materials or websites for me to reference? Thanks.

Hi, what is the use of PFC?

Then, if I would like to use a forward converter, how to use UC3844 to do it, or if UC3844 do as a controller in a forward converter? Does anyone has the simulation PSpice model in this IC?

Thanks for the suggestions. But, my product needs to do a buck (forward) converter to step dwon the 380V d.c. Would the UC3844 also act as a controller in the circuit? Besides, I would like to have the simulation first before making it practically. Does anyone have the PSpice model of the IC...

Hi. I would like to do a dc-dc converter which have output voltage equals to 12V and current is between 1.1A and 100mA. But, the input voltage is around 385V which is the voltage output of the PFC part. Since the voltage into the buck converter is so large, I would like to make a forward...

In a BJT Differential amplifier, how to find the maximum and minimum values of the common-mode input voltage? Beta and the resistors are given.

What is the use of Buffer connection Amplifier? What is the common mode rejection ratio? What is the use of this in the op-amp applications, for example in difference amplifier and instrumentation amplifier? What are the application in Difference amplifier and Instrumentation amplifier...

What is a PFC pre-regulator? What is the use of it? What is the circuit diagram in it when using buck converter? Please post some link about pre-regulator in buck converter. Thank you.:smile:

What is the use of Difference and Instrumentation Amplifier?

the picture which attached in the first post shows the input resistance.

Show that the input resistance Rin is given by Rin = RF/(1+Aod).

There is no relevant equation. The question is just find the expression of the input resistance.

Homework Statement A current-to-voltage converter The current source has a finite output resistances Rs, and the op-amp has a finite open-loop differential gain Aod. Show that the input resistance is given by Homework Equations Rin = RF/(1+Aod) The Attempt at a Solution Rin = RF...