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128 Threads found on High Voltage Divider
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 (...)
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 (...)
In the scenario in which one of the resistor from the voltage divider would fail open ( R76, R87, R94) I would have very high voltages to the op-amp inputs (U22). Those bidirectional diodes (D37, D38) are there to prevent that, by clamping those high voltages to about 2-6 V (from diodes 's (...)
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.
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. (...)
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?
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 (...)
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
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 (...)
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.
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.
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
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 (...)
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 (...)
yep, AVRs common ADC has a recommended input impedance of no more than 10Kohm... that voltage divider seems a little to high...
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
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
You won't use "very high" resistor values. Microcontroller ADC inputs work best with moderate source impedance, e.g. 1 - 5 kohms.
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
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?