I'm soldering a board recently, but I saw that the circuit requires 500k ohm and 5meg resistors. Do you have something similar that I can use? ?

asyua

I'm soldering a board recently, but I saw that the circuit requires 500k ohm and 5meg resistors. Do you have something similar that I can use? ? [Copy link]

 

I only have 499k ohm and 5.1M resistors, can this one replace those two resistors?

tagetage

As long as there is no special need for high precision, it is fine.

maychang

This depends on the resistance error requirements of the circuit you are welding.

The nominal 499 kilo-ohm and the nominal 500 kilo-ohm differ by only 0.2% and can usually be used interchangeably.

5.1 megohms and 5 megohms differ by 2%. This depends on the circuit's requirements for resistance error.

littleshrimp

LDO feedback resistor?

qwqwqw2088

Specific circuit specific

Look at the circuit board you soldered.

asyua

qwqwqw2088 posted on 2021-5-4 20:52 The specific circuit depends on what board circuit is soldered.

Thank you. I also want to ask, the 5meg one is a differential amplifier circuit, and the 500 one, um, it’s not 500k, I read it wrong, it’s a low-pass filter circuit, how should I read it? ?

asyua

maychang posted on 2021-5-4 20:14 This depends on the resistance error requirements of the circuit you are soldering. The difference between the nominal 499 kilo-ohm and the nominal 500 kilo-ohm is only 0.2%, which is usually acceptable...

Thanks, um, I misread it, it is 500 ohms, how should I use this error for the low pass filter circuit and the differential amplifier circuit that needs 5meg?

maychang

asyua posted on 2021-5-5 10:06 Thank you, um, I read it wrong, it is 500 ohms, how should the low-pass filter circuit and the differential amplifier circuit that requires 5meg use this error? ? ...

"How should I use this error?"

Regarding the error, we can only say: according to the circuit requirements.

For example, in audio amplifier circuits, the tolerance requirement for resistors is quite low, and a 10% difference may not matter, and the ear cannot hear the difference at all. In thermocouple or thermal resistor precision measurement circuits, the tolerance requirement for resistors is relatively high, and the error may be required to be less than 1%.

maychang

asyua posted on 2021-5-5 10:06 Thank you, um, I read it wrong, it is 500 ohms, how should the low-pass filter circuit and the differential amplifier circuit that requires 5meg use this error? ? ...

There are many types of multimeters, such as three-and-a-half-digit, four-and-a-half-digit, etc. Obviously, the three-and-a-half-digit multimeter has lower requirements for resistance error than the four-and-a-half-digit multimeter.

maychang

asyua posted on 2021-5-5 10:06 Thank you, um, I read it wrong, it is 500 ohms, how should the low-pass filter circuit and the differential amplifier circuit that requires 5meg use this error? ? ...

"How should I use this error in a low-pass filter circuit and a differential amplifier circuit that requires 5meg?"

Low-pass filter circuits often do not have high requirements for resistor errors, because the resistor error only affects the cutoff frequency of the low-pass filter, and the allowable error of this cutoff frequency is quite large.

maychang

asyua posted on 2021-5-5 10:06 Thank you, um, I read it wrong, it is 500 ohms, how should the low-pass filter circuit and the differential amplifier circuit that requires 5meg use this error? ? ...

"How should I use this error in a low-pass filter circuit and a differential amplifier circuit that requires 5meg?"

As for the requirements of the differential amplifier circuit for resistance error, it is difficult to say. It may be quite low or quite high.

asyua

maychang posted on 2021-5-5 10:29 "How should I use this error for the low-pass filter circuit and the differential amplifier circuit that requires 5meg? ? 』 As for the differential amplifier circuit's tolerance to resistor error...

Thanks,