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# High Voltage Divider

128 Threads found on edaboard.com: High Voltage Divider

## [moved] Circuit to detect 240 or 380 volts AC

Hi, everyone! I need to make a circuit that can sense if the mains voltage is 240 or 380 volts. In case it detects about 380 volts, a relay should turn on. I guess I need a way to measure the mains voltage. It doesn´t have to be precise. Can I rectify and filter the mains, and use a voltage divider to scale down the (...)

## Using an attenuator passive probe with a spectrum analyzer

a low frequency solution, like the X10 scope probe, will not work well with a microwave or even high frequency RF signal. I would NOT count on it being a 1/10th voltage divider either, since the spectrum an alyzer is a 50 ohm system, and a scope is typically a 1 Mohm system. I would put a 20 dB 50 ohm attenuator at the spectrum analyzer (...)

## overvoltage protection in inverter voltage sensing

I am working on 3 phaseAC machine inverter. For measuring the motor phase voltages I use the following circuit 135315 In my project the op-amps supply voltage is +/-5VDC; the inverter module supply voltage is +15VDC. These power supplies are deried from an isolated +5VDC supply. So the op-amps and the inverter module (w

## Biasing High Pass Sallen-Key Filter

My mistake, only one voltage divider is needed to make the half-supply bias voltage. The filter capacitor for it must have a high enough value for it to be almost a short circuit at your lowest frequency. Your biasing for the lowpass filter is correct.

## voltage divider without power losses

If you want it done with 0.00% loss, that's easy. Quit now. Resistive dividers have not only the inherent loss, but a dismal consistency of output relative to loading. Only a high-Z load would make any sense for using that. Depending on how many different voltages and how many at once, a multi-tapped xfmr with switches could be viable. (...)

## Power supply build query

A transformer provides isolation so that you do not electrocute yourself. The drill requires a high current. A voltage divider supplies a low current. Why don't you replace the battery?

## AC voltage measurement without transformer issue

No AC source is actually floating, and most likely you don't want to operate your circuit directly connected to the mains. A suitable solution for most applications is a high impedance (e.g. 1 Mohm to 10 MOhm) differential voltage divider. It involves some leakage current, but low enough not to trip any RCD protection or to expose (...)

## ADC with Voltage Divider

It probably has more to do with the writer not being fluent in English. Basically unless the know resistor is a high precision resistor (e.g. 0.1%) then your accuracy will vary according to that known precision. If you use a 10% resistor you won't get better than 10% accuracy in the unknown resistor value and if that unknown resistor is off by 10

## Frequency and current measurement for AC and DC Voltage using PIC16F1937

Assuming you are using 5V VDD and 5V as the ADC reference: 1. Use a 10:1 potential divider. If the current into the divider has to be very low (=high value resistors) follow it with a buffer amplifier. 2. Depends on the response time you need but simplest method is to convert the AC to DC and use a potential divider for the (...)

## LEM LV 25-P output drive

Won't consider AD817 as general purpose OP. Like other high bandwidth OPs, it has larger output current. But the OP would get quite hot. Still think that a passive resistor circuit is preferable.

## Link an inductiv sensor to a microController

If the sensor has an internal pull-up to 12V, try to adjust the high level voltage with a pull-down to ground, e.g. 2k.

## how to get Two Dc Outputs alternately

Dear, I have two output from two transistors. one output is of 300V for 180 microseconds and other output is of 9V for the remaining high pulse. How can i combine these two outputs. The problem is 300V, otherwise i would use comparator circuit for this problem. Could someone help me out. I'd really appreciate his/her effort. Thank you

## Can polarised electrolytic capacitors be used to make high/low pass filters?

An electrolytic capacitor is inaccurate because it has a wide range of tolerance. So if it is rated at 100uF then it could be anywhere from 50uF to 200uF. A polarized capacitor should never have reversed polarity. You got no sound because the low input resistance of what the high resistance filter is driving created a voltage divider. The RC (...)

## High Voltage Solar Dusk to Dawn system.(500V to 1000V represented as 0 to 10V)

Hello, I have 500V to 1000V DC output from comibination of solar Panels. Is it possible to design a circuit which will represent 500Volts to 1000Volts DC range in 0V to 10Volts DC so that I can control my output device as per the voltage. Similar to solar dusk to dawn street light, but high voltage. eg: 500V will be represented as 0V (...)

## Adc value to LCD using Arduino

yep, AVRs common ADC has a recommended input impedance of no more than 10Kohm... that voltage divider seems a little to high...

## High Impedance, Robust, Analog input stage for 20bit A/D

I believe you know that +/- 35V is no voltage range for a standard OP. So you have essentially these options: - use an expensive high voltage OP - design a discrete buffer amplifier - use a passive voltage divider, similar to an oscilloscope input

## Output voltage swing of Voltage amplification stage

3K is the input impedance of Q4. Yes. If the output is not zero volts current flows down R3, so Q2 adds/reduces the current current in Q1, which changes the output voltage back to zero. Its called negative feedback. For maximum DC stability, R2 should have a capacitor in series with, so the feedback at DC is 100%, and the AC gain would be the sa

## How to reduce voltage to meause it ?

You won't use "very high" resistor values. Microcontroller ADC inputs work best with moderate source impedance, e.g. 1 - 5 kohms.

## Designing circuit for providing isolation

You don't need an opto isolator, the differential amplifier will give you complete isolation. Just the standard four resistor diffential amplifier circuit: Make R1 and R2 both 200K Rg and Rf should be 2K4 That

## How to measure voltage of above 10kV using an MCU

I am trying to find a way to safely sample a high voltage output which will travel from about 1kV to 20kV (ramp). I think using a resistor divider should do the job. I have been successful at 1 kV - 2 kV range. I am just wondering if just by using a high impedance resistor will do the trick. Any advise?