Questions tagged [tolerance]

A window of acceptance, often expressed as a percentage, in which a non-perfect value is still accepted as usable.

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33
votes
8answers
7k views

Are two (or N) resistors in series more precise than one big resistor?

Let's say I have one 2 kΩ resistor with 5% tolerance. If I replace it with two 1 kΩ resistors with 5% tolerance, will resulting tolerance go up, down, or remain unchanged? I'm bad with ...
27
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10answers
9k views

Can a 10% resistor be used as a 1% resistor?

If my schematic calls for a 1% resistor, can I use a 10% resistor that measures to the correct resistance within 1% or is there some quality to tolerance beyond what it measures Ohm-wise? For example,...
26
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3answers
2k views

Why are resistors tolerances relative instead of absolute?

Every resistor has a tolerance, this provides the user with an idea of the accuracy of the product. This tolerance is represented by a percentage. This means: a big value resistor will be less ...
16
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2answers
972 views

4-bit bus address selection via analog input pin: Monte Carlo simulation shows overlapping address values

I designed a small sensor PCB for my master thesis with an ATtiny44 microcontroller. I need about 200 of these boards for my application and 16 are always locally connected to controller board. The ...
15
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6answers
5k views

Why are we still using resistors with %5 tolerance while they can even manufacture a 14.318182MHz crystal?

Year is 2012 and I can only find %5-tol resistors in the local market. They can make transistors at molecular scale, they can manufacture 14.318182MHz crystals, they can place trillions of flip-flops ...
12
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6answers
3k views

Resistors - binning and weird distributions

I read about a little quirk related to binning resistors in a comment on this recent question. Some manufacturers will sell, for example, 1% and 5% resistors that are really made in the same batch. ...
9
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3answers
1k views

PCB enclosure tolerances [closed]

I can imagine problems of PCBs not fitting into their enclosures or misaligned screw/hole pairs. Are these type of problems common, especially with the dirt cheap enclosures? I am planning to use one ...
8
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9answers
6k views

Reducing the tolerance of resistors manually

All the resistors available come with a finite amount tolerance. This is undesirable particularly in highly sensitive systems. While we can use resistors with the least tolerance available, I want to ...
7
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6answers
6k views

Resistor Tolerance - are measured resistor with the same value but different tolerances the same?

Probably a real newbie question but I can't seem to find an answer easily... If I have 2 resistors both 1K but one is a 1% tolerance and the other is 10% and I measure them and they are the same. Let'...
6
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6answers
1k views

Statistical accuracy of multiple resistors in series or parallel

I'm having a senior moment and would appreciate clarity. I'm working on an inverting amplifier design where I need to add low-pass filtering and a voltage clamp. Without the filtering and clamp, the ...
5
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2answers
8k views

Parts tolerance simulations in ltspice

I just recently found this tutorial (and various other places mentioning a similar technique) when trying to evaluate how one of my circuits behaves when using real world components with real world ...
5
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1answer
186 views

Why so much variance in the continuity beeper threshold? How do these beepers work anyway?

In this answer it is mentioned that the EEVBlog-branded BM235 meter has a threshold of between 30 and 480 ohms for its continuity beeper (as seen on page 25 of the datasheet). My first thought was "...
5
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2answers
1k views

5V Tolerance of 3.3V OUTPUT pin

Let's assume the following scenario: uC (@3.3V VDD) drives an I/O pin HIGH 3.3V (just to be clear, it's not an open-drain pin, so the p-channel mosfet of the output pin is actually driving the pin to ...
4
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6answers
1k views

What is the (most likely) technical reason behind temperature specifications?

Im talking about electronic devices, which may be handheld or similar, so nothing exposed to "artificial" temperature (welding, soldering, cooling with liquid gas). Devices designed to be operated by (...
4
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5answers
2k views

Rules for choosing power rating of a resistor

Let's say we're designing a system, and within it we have some resistor \$R\$ with a voltage difference \$V\$ across its terminals. Then it dissipates power \$P = V^2 / R \$. Of course the resistor ...
4
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1answer
3k views

How to calculate aging tolerance of Resistor?

I wanted to calculate the worst case minimum and maximum value of Resistor 1K by considering all the tolerances(initial tolerance,temperature,environmental factors and aging). Here is the link for ...
4
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1answer
945 views

4/5 band resistor - extra black band

I have two resistors which need to be replaced. I tried to determine the value, but it can't make sense of these black bands: For reference the bands are: brown - silver - green - brown - black ...
3
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2answers
634 views

Confusion with the meaning of a component tolerance in terms of accuracy and standard deviation

As far as I understand a component's tolerance relates the difference between the actual component value and the value given on the data sheet. If a 1k Ohm resistor have ±5% tolerance, is this 5% ...
2
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4answers
1k views

Jitter in 'ppm' and 'ns'

In many datasheets clock tolerance is in ppm and in some other it is in ns or ps. What is the difference in giving clock tolerance in ppm and ns/ps. How it can be converted from one unit to another?
2
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4answers
2k views

Hand-matching resistors: high-end DMM vs Wheatstone bridge

I wrote an article dealing with the question of hand-matching resistors to high tolerances using a DMM. The driving purpose behind that article is to show that it's harder to do that than one might na&...
2
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4answers
636 views

soldering input pins to SN74HC595N shift register — heat tolerance

I'm working on a project that uses the SN74HC595N shift register from TI. The nature of this project requires that I solder on pin extensions. My soldering skills are not too solid, so I'm worried ...
2
votes
1answer
445 views

1.2 GHz Cloverleaf Antenna tolerance

I'm working on building my own Cloverleaf antennas, to work at 1.2 GHz, for the video system on my Quadcopter. At this frequency, what kind of tolerance am I looking at in terms of the length of the ...
2
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2answers
472 views

Component has a x% tolerance: What does this mean exactly?

All components have specification tolerances and ranges. Some examples are:- Resistor 1% Electrolytic capacitor 20% Zener diode breakdown voltage 5% Clearly it kinda indicates that the ...
2
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1answer
234 views

Forward voltage tolerance on an ordinary diode

If one examines the datasheet of a diode such as the Vishay US1G, there is a graph of the typical voltage vs current such as Figure 3 below (with multiple lines for different temperatures): However, ...
2
votes
1answer
78 views

Should I be conservative about setting the output voltage of the CV phase of Li-Ion charging

Background My application features a Li-Ion battery (NCR18650B) which I'm charging with the standard CC/CV method. Various constraints force me to use a generic buck converter (with current limiter) ...
2
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2answers
545 views

What is life tolerance of a resistor?

Is anyone familiar with the term "life tolerance of a resistor" ? I could not find a good read in google. Any link with the explanation will be sufficient.
2
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1answer
359 views

PCB mounting - flatness

Let's say I have a square PCB with mounting holes near each corner and that the PCB will be mounted to an enclosure with 4 standoffs. Is there a rule of thumb about how much tolerance I can have on ...
1
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2answers
774 views

Transformer tolerances?

How much can a transformer go without a failure? For example, let's say that a transformer is designed to work with 500mA. (obviously you should avoid exceeding this limit) But as I learned with ...
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2answers
84 views

choosing crystal when tracks are very close together

This is a circuit I am having trouble with. I made 20 units with the exact same setup. Three units with this setup managed to work with 33pF ceramic caps with 20% tolerance and a crystal from Ebay. ...
1
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1answer
281 views

What capacitor types perfom best for large-value signal path applications?

Most signal path/timing capacitors are of stable types such as film or C0G ceramic. However, size and cost force an upper limit on this -- C0G caps out at 10-100nF, while film caps can manage up to 1-...
1
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2answers
3k views

5v tolerance on 3.3v PIC

Many PIC microcontrollers such as PIC24EP512GU810 have 5V tolerant pins. My question is how does this work. Do these devices have clamping diodes for ESD protection? Would clamping the input voltage ...
1
vote
2answers
126 views

Do photodiodes have tolerances?

Below is the beginning schematic for a circuit I'm working on. We have a previous revision of that product (Rev A), and two sets of recent product (Rev B1 and B2). Rev B1 was made 2 weeks prior to Rev ...
1
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1answer
155 views

Identification of 5 band Resistor from power supply

This Resistor is not functioning The 4th band is Gold, I've read that means it's an exception. The 3rd looks to me as silver, not gray, this is why I've added a picture. I'd like to replace it, so ...
1
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3answers
188 views

Cheap precision sense resistor

I need a precision low value sense resistor to make current measurements e.g. 10R 0.01R. Looking for precise resistors e.g. Vishay, show that these are expensive e.g. $35 for a single 0.001-0.005% ...
1
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1answer
2k views

Tolerance of a ceramic capacitor

I have a ceramic capacitor that reads "101 Suntan" (and nothing else.) Reading up on how to interpret capacitor labels, I believe this capacitor is 100pF. I'm having difficulties trying to determine ...
1
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1answer
120 views

How do I model a resistor array in SPICE?

I am currently building a library of SPICE simulation models that is going to include resistor arrays. These arrays exhibits both absolute tolerances and relative tolerances. Usually, the relative ...
1
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1answer
126 views

How many bins can I code using a resistor on an ADC

I have a device that can have different things plugged into it. I'm trying to use a resistor on these things to uniquely identify the thing. That is, if I plug in Thing A, I can read the resistance as ...
1
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1answer
3k views

PCIe add-in card thickness tolerance

I can't find a tolerance measurement for the 62 mils thickness specified in the PCIe electromechanical spec. How much leeway do I have for board thickness in an add-in card. Additional details: I'm ...
1
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0answers
999 views

differential amplifier inaccuracy resistors exercise to calculate CMRR

The common mode gain for a differential amplifier in the general case is: $${V_o \over V_c }={ R_1R_4-R_2R_3 \over R_1(R_3 + R_4) }$$ simulate this circuit – Schematic created using CircuitLab ...
0
votes
3answers
4k views

Can I use a 5% tolerance resistor instead of a 10% tolerance resistor?

can I use a 5% tolerance resistor instead of a 10% tolerance resistor? It is for an organ from the 60's. All resistors stated in Schematics are 10% 1/2 watt. But I can't find a 6.8k 1/2watt 10% ...
0
votes
2answers
127 views

Why do I read resistance on the continuity setting but not on the resistance setting?

Disclaimer: Newbe A multimeter tutorial on Youtube said that to test my washing machine inlet valve solenoid for continuity I can use either the lowest ohms setting (200 on my DT830B) or the ...
0
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3answers
70 views

How much can a power brick safely vary from what the device it's used with expects? [duplicate]

How much can a power brick safely vary from what the device it's used with expects? As an example, let's say I have a device that needs an AC=>DC power brick. The device expects 19V/1.58A, but the ...
0
votes
2answers
425 views

Total Tolerance of an Electonic Circuit

I am trying to evaluate a circuit with a lot of parts given their associated tolerances and I'm really struggling. For the electronic parts with 2% tolerance I am guessing the values are to ...
0
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2answers
481 views

Replace Tight Capacitors for Better Tolerance?

There are some capacitors (10 \micro F and 4.7 \micro F) which are limiting my development of Raspberry Pi Hats because they are provided only with tolerance of 10% or greater. It seems that the ...
0
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1answer
332 views

Problem with accuracy of AD633 multiplier

I have 3pcs of AD633 chips, and the accuracy should be ±1% (typical), ±2% (max) according to datasheet. I wired it like this: I tried several input voltages, but it seems, that output is still way ...
0
votes
1answer
57 views

Meaning of a potentional tolerance value for a dimension in a mechanical drawing

The mechanical drawing below contains two dimensions (2-Ø2.30 and 4-Ø0.92) that I can't make heads or tails of. I have spent quite a while researching mechanical dimensional and tolerance conventions ...
0
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1answer
210 views

What does the tolerance mean for the 0 ohm resistor

What actually is the percentage tolerance if resistor is 0 ohm?
0
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1answer
39 views

Constant current circuitry tolerance dependency

I have the below given circuitry. The circuit provides ( 12 - 3.3 = 8.7 V) 8.7 V / R3 of current. My specific question: What is the effect of PNP transistor on the variation of current? Until ...
0
votes
1answer
86 views

Toubleshooting PCB circuit - strange Zener diode behaviour

I have two units of a device which I shall call deviceA and deviceB. DeviceB is malfunctioning. Therefore I compared the resistance values of the same components on the boards of both deviceA and ...
0
votes
2answers
96 views

RTC time advancing

I'm working in some projects with an RTC. I'm using the PCF85063A. The problem is: the RTC counter is advancing from real time about 2 minutes per week. I searched for hardware and firmware errors, ...