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-1
votes
3answers
129 views

Battery indicator Circuit

Many of battery indicator circuits are designed using 2 or more leds like in the image above but how to design a simple battery indicator circuit using only RGB LED and transistor for 12v battery ...
2
votes
1answer
122 views

Noise generator with LM318

I want to build a noise generator from a Zener diode. I designed the above circuit. The noisy voltage from the diode is filtered via a high-pass filter and input into a 92x gain non-inverting ...
1
vote
1answer
100 views

How does this Current Comparator Circuit Work?

I have a quick couple of questions about this circuit: The schottky diodes are obviously for minimizing slew delay but how exactly do they do this? If the non inverting input is tied to ground and ...
1
vote
3answers
116 views

High voltage to low voltage in ps/nanosecond time (Zener/opamp?)

So I have a signal that goes from 0 to ~800volts in 30ns. I would like to use this signal to trigger a camera (input impedance of 50ohm) which takes a max of 10 volts and requires the rise time to be ...
0
votes
1answer
387 views

Op Amp as a simple switch

I want to build a little voltage switch that switches on a buzzer and a relay when a certain voltage is reached. Please have a look at the schematic. I use a trim potentiometer to set up the switch ...
0
votes
1answer
247 views

Zener diode at inverter op amp's output

I would like to know what would be the effect of placing a Zener diode between the op amp's output and the actual output of the circuit like shown in the schematic. The Zener should be of 5 V. ...
1
vote
1answer
173 views

LM311P op-amp strange behavior in comparator mode

I'm trying to build a schematic which will turn on a relay in case motorbike battery voltage will reach some level. I've ended up with the following schematic. simulate this circuit – Schematic ...
0
votes
2answers
113 views

Transfer Function of Op Amp Circuit

How can I obtain the transfer function graph of this circuit, assuming the zener diodes voltage are 4.3V and silicon diodes 0.7V.
1
vote
3answers
156 views

Op-amp circuit analysis without input signal

In the following circuit i need to find the OUTPUT and the current that flows in the zener diode D1, which works at the "zener" breakdown region with $$Vzener=5,6V$$ The opamp is considered to be ...
1
vote
1answer
955 views

Op-amp with zener diode

In the following circuit i want to find the output voltage Vo related to the input Voltage Vi. Diodes D1 and D2 are the same and have a 0,7V drop when they conduct. Op-amp is ideal too. For the zener ...
-1
votes
4answers
192 views

What exactly is the definition of a voltage regulator?

I was assigned to design a voltage regulator for a secondary ECE circuits class, and I would like to know precisely how that element is defined, given the following. It has an input and an output The ...
1
vote
1answer
282 views

Expressing output voltage in a circuit with zener diodes without any value given

I have this circuit and I need to find \$u_{o}(u_{i})\$ if \$ZD_{2}\$ and \$ZD_{1}\$ are ideal zener diodes with \$U_{z}\$ zener voltage and the op-amp is also ideal. My problem is that I have no ...
1
vote
3answers
156 views

What is the output voltage in this case?

What happens when the output voltage of an op-amp (say in a voltage follower/inverting configuration) should be higher than a certain amount (say 10V) and on the output I place a 5V zener diode in ...
2
votes
2answers
589 views

Opamp Zener Regulator Configuration

[No TL;DR provided] I am an undergraduate electronics engineering student and I am working on designing a linear bench top power supply with foldback current limiting. Inspired by designs all over ...
1
vote
3answers
394 views

Do I need buffers prior to a comparator?

I have the following circuit which generates digital noise... The reason for the 2 diodes has to do with stochastic uniformity of the noise output and I don't really want address this aspect. The ...
0
votes
1answer
274 views

Setting maximum opamp input voltage by zener diodes with respect to supply voltage

When I was about to implement a circuit with a 24V supply voltage I noticed that the comparator's inverting input in the part below receiving 24V with respect to ground when the input signal goes high....
1
vote
3answers
986 views

zener diode protection on input of op amp?

I saw a zener diode protection circuit on an Arduino analog pin, and it had a 1k ohm resistor in series. I want to protect an op-amp, and I don't see why I need the 1k resistor, so the question is ...
0
votes
1answer
617 views

How do you solve for current through a zener diode once it has reached its zener voltage?

I am doing test prep for an exam tomorrow and ran into this problem. The question asks you to plot Vo in terms of Vs. It also provides information that the zener diode is ideal and that its zener ...
-1
votes
2answers
70 views

What is the function of this opamp circuit? [duplicate]

Hello ladies and gentleman, I'm trying to figure out how this circuit works : I was thinking it is a kind of charge controler where Rx is the load. Any help would be pleased
0
votes
2answers
633 views

Feedback op-amp voltage regulator help

I have made a voltage regulator: simulate this circuit – Schematic created using CircuitLab And here is the zener circuit: simulate this circuit I have already tried to charge a device ...
2
votes
4answers
772 views

Virtual GND resistor dividor vs zener diode

I was having a discussion with someone about using a virtual gnd for an opamp circuit. One way to provide the VCC/2 voltage is with a voltage divider made of two precision resistors (and a capacitor ...
0
votes
1answer
486 views

Why use two power sources when designing a voltage regulator using a zener diode

I am currently designing a voltage regulator using a 5V zener diode. I am wondering why some people choose to use two power sources instead of one, what would be the benefits of this ? the circuit ...
8
votes
2answers
9k views

Using 1N4148 As A Temperature Sensor

Can I know which component senses heat or acts as heat sensor in the following circuit? In the given diagram, it is said that the 1N4148 diode acts as the sensor. But basically it is a zener diode and ...
0
votes
1answer
1k views

non-inverting schmitt trigger op amp - replacing a zener diode on the input

I wonder if it is possible to replace the second figure below with the first one? Would both Vo output be the same on the figures below? If they are different, ...
3
votes
1answer
9k views

Voltage regulator design with op amp

What's wrong with this scheme? I expected to be able to set the output voltage value modifying the values for R4 and R5 (I can replace them with a potentiometer), and why do I have negative voltage at ...
4
votes
2answers
3k views

How do I use a clipping Zener at the input of an Opamp inverting amplifier?

I have a \$ V_{in} \$ signal for which I cannot guaranty that it would have an upper limit. I want to clip this input signal to a limit (e.g.; 8.2V) with a circuit like above. Is this circuit alright?...