U37 is a 741 op amp

U34 is a Multiplexer 4053

Pin#14 has an AC voltage

U37 output is in DC volts

1.) How does the U34 the multiplier convert an AC voltage into a DC voltage or does U37 convert the AC voltage into a DC voltage?

2.) R203 is a 88.7 k ohms , the AC voltage is in AC millivolts , the resistor has drifted to 88.3K ohms

88.7K ohms to 88.3K ohms is a big change when dea

I have built a high current driver board that can handle 12 to 24 volts dc up to about 30 amps. To turn the mosfet on you have to place a voltage on the gate. At 12 volts I can simply take the same supply voltage, pass is through a 100 ohm resistor and turn the mosfet on. At 24 volts this would be too high a voltage for the gate as the spec sheet says max gate voltage should be +-20 vdc.

Hello everybody,

I am having some issue to analyze a resistor network i am working on.

I was able to analyze a more simple one but i am stuck on this one.

The network is shown on the attached file.

I know the resistors values (21 resistors in total) and the source voltage as shown on the pdf.

I would be glad if someone can help me a little on that.

I've never used a 741 and decided to play with one today. Wired it up as a comparator like the circuits shown here:

http://www.circuitstoday.com/voltage-comparator

I am using 5 volts as my supply voltage and instead of the two fixed resistors as a voltage divider I am using a 100K pot to vary the voltage. I used a fixed voltage divider to give my reference voltage of 2.5 volts.

Hi Everyone,

I have another question from Electronic Principles page 864 regarding integrators. I attached an image for clarification.

The book discusses the use of a resistor in parallel with the capacitor to account for input offset voltage. If I understand this correctly, the resistor limits the voltage gain, thereby limiting how much this offset voltage charges the cap.

I am trying to analyze a circuit using source transformations (converting from a voltage source to a current source). I am trying to understand how they work based on a book, but I keep getting confused based on a simple example.

Here's another question I'm not quite sure about. Its asking to determine it unmarked resistor's resistance value using Ohm's Law. Show calculations that result in the VI ratio of 600 ohms.

dear sirs
i want to connect 20 leds in parallel.
my source is 2x 4.2v batteries parallel
led voltage white 3.4v 20ma
in the following page i can find that i need 20 resistors 47ohms
http://led.linear1.org/led.wiz

now in other page
http://www.hebeiltd.com.cn/?p=zz.led...tor.calculator
i find out that i need resistor 2ohms 03w
does it mean that i need 1 resistor for all circuit?

Ok so in voltage divider biasing of base of NPN BJT transistor, the voltage divider determines the quiescent voltage. 10k and 10k would put 4.5v across the base. 100 ohm and 100 ohm for R(L) and R(E).

Doesn't current flow from the bias resistors at the base to ground through the emitter? How come the voltage is still 4.5v (-the voltage drop)?