Questions tagged [component-values]
The component-values tag has no usage guidance.
57
questions
2
votes
1
answer
42
views
Please identify this burnt SMD component in this LED driver PCB
This is an LED driver labeled as ED-SC 50W1200 (on the plastic housing) and no data is written on the back side of the PCB.
The other side of the PCB is immersed in a black resin that is now locked as ...
- 123
1
vote
1
answer
108
views
Need help finding specs for RV1 & RV2 varistors on fried board [closed]
Power surge blew 6 appliances and am hoping I can repair some of the boards. I cannot identify blow varistors in RV1 & RV2 positions on Saeco IG 1.9.168.00_V04 board. Any help would be appreciated!...
2
votes
1
answer
537
views
Buck converter with UC3843
I am building a simple buck converter circuit with a current-mode control IC, the UC3843.
In the application note of the UC3843, a sample circuit is given:
I am completely clueless about how these ...
- 31
3
votes
4
answers
918
views
Voltage rating of a Zener diode
How do we find the voltage rating of a Zener diode found alone by chance, when the only way to identify it is to inspect, test, and so on?
- 399
2
votes
1
answer
95
views
Help identify this resistor
I'm a little stumped by this one. I'm currently repairing an old control board, and replacing the majority of the components.
I've come across this resistor (pictured below). Reading the color band ...
- 93
2
votes
2
answers
195
views
What resistor could I replace this broken one with?
Can anyone help decipher what resistor this is? R1 - I am struggling to figure out what the resistor is as it is blown and the colour bands are burnt:
Circuit board has written on it
0L-A011-POWER-...
- 21
9
votes
3
answers
975
views
How do you read this resistor value?
Home hobbyist here. I'm trying to be a little more automated in my reading of resistors. I've gotten pretty good at reading the 4 bands with the beige background, I find the colors easy to read, and ...
- 455
0
votes
1
answer
284
views
WS2811 MOSFET driver - components help
I'm trying to build a board capable of driving 12 V, single-channel, non-addressable strips with the WS2811 protocol for my project. In my case I want to be able to safely switch up to 5 A (but most ...
- 3
0
votes
2
answers
91
views
Op-amp plus diodes: resistors' values calculation
I am tasked with following: R1, R3 and R3 are to be calculated so that the diodes work in forward bias. Assuming the diodes have a voltage drop of 0.7 V and the op-amp is ideal I have calculated that ...
- 41
6
votes
1
answer
395
views
Help me identify a resistor
I don't see what it is. I think it is a 56 Ω resistor. Is that correct?
- 167
12
votes
1
answer
1k
views
Resistor 100k¾ indicated in datasheet
I was reading the datasheet of a digital multimeter (DMM) and I came across a resistance value terminated with 3/4, like so:
You can find it at the bottom of page 1-3 of the this document.
What does ...
- 169
0
votes
2
answers
94
views
How do I find resistors values for a TTL to ECL interface?
This is the photo of the ttl to ecl interface
1
vote
1
answer
345
views
Choosing capacitor for the filter of a three phase full wave rectifier
I am designing a power management unit (PMU), which takes the power from an alternator (alternator output: three phases, 30-85VAC, 35-130Hz, Max current: 20A).
I want to reduce the ripple using ...
- 33
34
votes
3
answers
21k
views
Why does the E12 resistor sequence use 27 and 33 instead of 26 and 32? [duplicate]
On the assumption that the E12 values were chosen to be equally spaced logarithmically between 10 and 100 ohms we get the ideal values of:
10.00
12.12
14.68
17.78
21.54
26.10
31.62
38.31
46.42
56.23
...
- 579
2
votes
1
answer
264
views
I need help on identifying the value of a schematic symbol
I came across the schematic of RAK3272-Sip development board, but I couldn't identify the value of this inductor.
Here's a link that contains the full schematic.
- 23
2
votes
1
answer
86
views
Mysterious component marking
I have stumbled across this component which I’m trying to replace. It has a rating of 22mΩF.
It looks to be a resistor but I am confused as to why there is an ‘<...
- 75
1
vote
4
answers
641
views
Silver band at 3rd from 5 band resistor
I need help to find this resistor value. They’re 5 band resistors and it has silver band at 3rd. I try to use online calculator but can't calculate this silver 3rd band.
It’s a faulty resistor so I ...
0
votes
1
answer
75
views
Defective Transformer Replacement
I've been working on repairing a TV psu, and discovered that the transformer in it is faulty (reading O.L. on every combination of pins except for diagonal in ohms mode on the DMM)
I've been looking ...
2
votes
2
answers
992
views
Identifying unique color code of non-inductive wire wound resistors: Weird resistor color coding, never seen before
Here we identify the color code determining the values of non-inductive wire wound resistors, specifically Yageo's NKN series (but applicable to other manufacturers of this class), which are a unique ...
- 775
42
votes
3
answers
11k
views
Why is the number 63 popular in electronics?
Capacitors have a voltage of 63V (not 60 or 65).
Fuses have a value of 63A (not 60 or 65).
And there exist more odd values in electronics...
Who knows the history of this convention?
1
vote
2
answers
446
views
Resistor with silver third band
This resistor, from the AC side of a power supply board, has a silver third ring and a white fifth ring. I've never seen such component before :
It reads between 8 and 12 ohms on the multimeter and ...
- 13
0
votes
1
answer
303
views
What's the purpose of the resistors and capacitors in this latching push button circuit?
I am trying to design a push button that turns my device on upon a single press and turns it off upon holding the push button for a few seconds.
I found this circuit:
Aside from the 10uF capacitor ...
-4
votes
2
answers
118
views
Conceptual vs real world signal transmission [closed]
When data or information is sent through any medium, (be it through phone lines, cable, fiber optics or through empty space or some other means), is it volts, current of charges, 0s and 1s, codes, ...
- 137
0
votes
2
answers
2k
views
SMD Resistor Power Rating Calculation
I'm extending my question from previously.
How to find SMD resistor and capacitor value and correct size
I'm doing some calculation and find something confusing below is the calculations:
V = 5
R = ...
- 23
0
votes
0
answers
90
views
Help identifying surface mounted component
While replacing the damaged screen on my wife’s Pixel 3a, I damaged one of the blue components below the FPC connector that connects the LCD assembly to the main board.
Can someone tell me what these ...
- 101
2
votes
1
answer
327
views
Identify SMD capacitor value
I'm repairing a Breville Smart Grinder circuit board and found that the issue is due to a bad capacitor.
I have removed the said capacitor (C15 in the schematic below) and I am now wondering how to ...
- 25
1
vote
1
answer
93
views
What are the values of these 2 resistors?
What are the values of the two highlighted resistors?
Considering the brown band as tolerance and ignoring the first (black) band, I came to the conclusion that the values are 680 and 220 milliohms. ...
- 13
0
votes
0
answers
65
views
Typical rms values for random jitter in satellite communication
I'm trying to find typical values for random jitter in satellite communication and I'm not really finding any values in any documents. Most of the time I only find definitions for different jitter ...
0
votes
1
answer
221
views
Capacitor values
I don't have high-end multimeter. So, anybody please tell me the values of the following capacitors.
- 63
1
vote
2
answers
328
views
Variable resistors - resistance value meaning
I'm normally using in my circuit board a 10K variable resistor. Those specific 10k variable resistors are no longer in my supplier stock for now and I was wondering if I can place a 200k variable ...
- 33
1
vote
3
answers
476
views
Help Identifying Inductor From a Schematic
I’m repairing a laptop but I don’t know what value inductor to use/get. The schematic has values, I just don’t know how to interpret other than it’s a 2mm inductor. It’s labeled 5A_Z120_25M_0805_2P on ...
- 13
8
votes
3
answers
7k
views
How do I change the output voltage of the LM7805?
I read in the LM7805 datasheet that I can change the output voltage to not only 5 V, but to another value by changing the circuit resistance. How do I do that?
From what I understand, to change the ...
- 81
3
votes
3
answers
1k
views
Does "1KV" on this disc capacitor mean 1 kiloVolt?
One of my power supplies died. Investigation turned out that this capacitor is broken. "102" means 1nF, but does "1 KV" mean 1 kiloVolt or is that some sort of tolerance code?
I've tried several "...
- 950
1
vote
3
answers
1k
views
Identify unknown capacitor and resistor values
How can I find out what the values of R12 and C3 are?
- 113
0
votes
1
answer
99
views
Can someone help me identify what the value of this capacitor is? [duplicate]
I have an older computer and as I was pulling the graphics card my fingers slipped and I pulled this off the board... Problem is I can't find one with the same markings so I need to find a replacement....
2
votes
1
answer
687
views
How can I identify these capacitor values?
I’m trying to build the power supply from this schematic.
I’ve been purchasing the parts, but am confused about the capacitors I’ve labeled, especially became their numbers start with “R”. What are ...
- 207
0
votes
2
answers
409
views
Uses for 49.9Ω resistors? [duplicate]
It seems that both 49.9Ω and 50Ω resistors are a thing:
https://www.mouser.co.uk/Passive-Components/Resistors//N-5g9n?P=1z0wnltZ1z0wljo
https://www.mouser.co.uk/Passive-Components/Resistors//N-5g9n?P=...
- 543
1
vote
1
answer
528
views
Condition for the output and input impedance for cascading electronic circuits
For cascading a system that have an output impedance of \$R_1\$ and an op amp that has an input impedance of \$R_2\$ then in order to use a isolated model we need a value for \$R_2\$ that is minimal ...
- 331
1
vote
2
answers
596
views
Does the resistor values used for opamp circuits come from the equations?
I've the following circuit:
I used the LM741 as the opamp. The input resistance is \$2\cdot10^6\space\Omega\$, the output resistance is \$75\space\Omega\$ and the voltage gain is \$2\cdot10^5\$.
...
- 331
1
vote
2
answers
2k
views
TBD resistor & capacitor(TBD means "To Be Discussed")
I’m building the * DN05017/D
power supply from ON Semiconductor. This is the datasheet of the power supply with schematic and BOM
So now while searching for the components, I noticed on the schematic ...
0
votes
2
answers
267
views
Will this MOSFET Work in this circuit?
I have designed printed circuit board for a project that requires a (logic-level) MOSFet controlled directly by an AVR micro at 5 volts feeding a step-up transformer. The boards have already been ...
1
vote
1
answer
8k
views
What is the value of this capacitor?
I have a bunch of these, and I can't remember what I thought they were when I bought them. I've googled a ton of possible (yet conflicting) potential value options. Looking for some expert advice.
...
- 111
2
votes
1
answer
1k
views
Adapting an HF attenuator to higher power
I want to make a 25W HF amplifier that can handle an input up to 8W. I found a schematic by ON6MU which can handle up to 2.5W input. There is an attenuator at the input that I copy here. R3-4 is 1W, ...
user17592
2
votes
2
answers
8k
views
Tantalum Cap Code Explained
I need to replace the following cap:
It was placed at the input of a device that runs off 24Vdc, like the following schematic.
simulate this circuit – Schematic created using CircuitLab
I'm ...
- 518
1
vote
1
answer
1k
views
Y Capacitor Value Confusion
I was cleaning my 36v dc 5.5 amp SMPS today. I was playing around with the wires and goofed up. A spark happened and later I found that a Y Cap had cracked.
This cap value is:
Yf222m 2200pf 250v x1:...
- 11
2
votes
2
answers
263
views
How could I go about determining the component values of the described filter? I know what they are, but not how to get them using proper formulas
The filter in question takes a mono signal of amplitude between 5 mVp and 200 mVp, and filters the signal based on the frequency. The potentiometer that leads into the inverting input of the op amp ...
0
votes
2
answers
674
views
Capacitors minimum value
When the manufacturer recommends some capacitors with specific values, can I choose caps with more capacitance? Will it give any advantage? For example decoupling caps at MCU power pins. Or LDO input ...
- 523
1
vote
2
answers
6k
views
What happens if I change the value of a coupling capacitor in a tube pre-amp
I own a Blackheart BH1H amplifier and am considering making modifications to change its sound.
The schematic can be found here
One change I have seen suggested is to change the value of C2 from it's ...
- 1,039
23
votes
2
answers
4k
views
Why are there 3.15A fuses?
Why are there 3.15A fuses?
Did someone decide that \$\pi\$A was a good rating?
Or is it \$\sqrt{10}\$A they're aiming for?
Is it even possible to make fuses with better than +/-5% tolerance?
- 32.2k
0
votes
3
answers
1k
views
What value PTC Thermistor should I choose for over-current protection for a child's electronics kit?
What is an appropriate value for a PTC thermistor used in a 3-cell AA battery pack to provide over-current protection if the terminalsare shorted? Current draw during normal operation will be only a ...
- 1,039