All Questions
Tagged with transformer capacitor
78 questions
9
votes
3
answers
2k
views
Why does this arc die in the center?
I discharged a capacitor across the primary of an old microwave oven transformer. As expected, the transformer made a huge spark. I am generating the spark by charging a capacitor with a bug zapper to ...
- 193
0
votes
1
answer
387
views
How does a capacitor coupled voltage transformer (CCVT) and spark gap work?
What is the actual purpose of a capacitor coupled voltage transformer in a substation?
What I do know is that they offer low impedance to the very high frequency signal, so it does not get into the ...
- 165
0
votes
0
answers
88
views
What's the best way to measure air-core transformer and variable capacitor using an LCR
In order to create a model I need to measure the capacitance of a variable capacitor and an air-core transformer. This is my first time dealing with old models of capacitors and inductors and I'm ...
- 11
0
votes
1
answer
97
views
Connection between 2 PHYs - how?
I want to have a PHY-to-PHY Ethernet connection on the same PCB but cannot disable AN and Auto-MDIX (no register access available)?
Use capacitive coupling anyways or use magnetics instead? If ...
- 945
0
votes
1
answer
95
views
Is this a right magnetics termination for PoE and non-PoE application
I came across the below schematic image while trying to read Bob-smith termination.
Would there be any problems with the termination on the right side with and without PoE?
Can someone explain a ...
- 945
3
votes
1
answer
849
views
How does a microwave oven transformer shunt help resonate the voltage doubling capacitor?
I was reading this great answer by Neil_UK, and a comment-question was:
Comment Question 1
Are MOTs belonging to the general type called "Leakage/stray field transformer" ?en.wikipedia.org/...
- 2,980
3
votes
2
answers
628
views
Half bridge SMPS with polypropylene film capacitor
I dismantled a cheap Chinese 240VAC to 48v-20A SMPS to try to understand the basic working principle.
There is a CBB22 335J630V polypropylene film capacitor in it. I have drawn it in red on this basic ...
- 349
0
votes
1
answer
235
views
Connecting two of these DC power supplies in series
I have two identical power supplies which output 16.5V DC. They seem to be isolated by a transformer and an optocoupler, but there is also a 1kV 2.2nF capacitor between the primary and secondary side (...
- 147
14
votes
1
answer
3k
views
Are these transformers or giant capacitors?
I sometimes see these devices along power lines when I'm driving and was wondering what they were. They look just like the regular transformers that I see on top of electrical poles, but it seemed ...
- 377
0
votes
1
answer
123
views
Does a transformer have different primary and secondary PFs?
I tried connecting two energy meters on primary and secondary and found that they were showing different values when a load was connected to the transformer.
Does a transformer have two different PFs, ...
- 73
2
votes
1
answer
238
views
What is the function of the capacitors and MOV on the outlet receptacle of this isolation transformer?
I recently purchase a used Tripp-Lite IS250 isolation transformer off of eBay. Here is the datasheet. It's a fairly open secret that these are not true isolation transformers suitable for a tech bench,...
- 314
2
votes
1
answer
227
views
How does a capacitor double the transformer output?
I recently got a transformer with a ratio of 10/1 and fed 40 VAC into it.
I got the ~350 VAC on the secondary which was expected.
When I connected a 1000 V, 1 μF AC capacitor to the secondary its ...
- 23
17
votes
4
answers
4k
views
I ripped the lead off this film capacitor by mistake - is it beyond repair?
As the title says, I accidentally ripped the lead off this film capacitor. It was the only one I had - am I out of luck, or can this be soldered back on? I've provided photos, including one under my ...
- 314
1
vote
2
answers
837
views
Capacitor amplifying voltage in bridge rectifier
I made a bridge rectifier using 4 1N4007 diodes, a capacitor filter with capacitance of 470 micro farad (25V), and a resistance of 1k ohm as a bleeder resistor and a step down transformer with ...
- 13
8
votes
2
answers
347
views
Why the effect of a triphasic capacitor could be as twice as its rated kVar? *(check Update 1)*
Why the effect of a triphasic capacitor could be as twice as its rated kVar?
Please check Update 1, since if its true, then I think my issues are solved.
Intro
This is a real life case of a client of ...
- 131
0
votes
2
answers
193
views
Can you charge a capacitor merely with static electricity where charges don't move? [duplicate]
I have gone through the following links, but they all talk about moving charges in some sense:
Charge capacitor with static electricity ,
How to charge a capacitor with static electricity? ,
Can a ...
- 73
2
votes
2
answers
621
views
Can you charge a capacitor with very high voltage and no or little current from secondary side of a step up transformer?
Based on the research I did online and after reading basic electrical books I understand that a capacitor stores energy in the form of electric fields. So I understand that, to charge a capacitor, all ...
- 73
1
vote
0
answers
157
views
Ethernet centre tap capacitor on transformer
I'm using the LAN9353 IC with this evaluation board as a reference.
On page 5 of the evaluation board manual, the centre tap capacitor on the transformer is 22 nF.
When the value is changed to 100 nF, ...
user220456
0
votes
1
answer
117
views
Is there a relationship between capacitor ripple current and the transformer secondary current output rating?
As an example: I was looking at a 10000 μF, 50 V capacitor with a ripple current rating of around 5 A at 20-120 Hz.
My transformer secondary is rated for 24 VAC, 20 A.
- 409
0
votes
1
answer
424
views
Magnetic energy harvesting with a current transformer
I am planning to design a magnetic energy harvesting circuit with a current transformer (CR8349-1500) to charge a super capacitor.
Load current rating is 0 to 35 amperes. From the current transformer ...
- 87
1
vote
1
answer
149
views
How can I find out what voltage a cd player requires? [closed]
I Have a new CD player which is 120v 60hz 15Watts. It was plugged into UK voltage 240v and the transformer burnt out. I want to change the transformer to allow 240v intake but I don't know how to tell ...
- 11
2
votes
4
answers
499
views
Which components cause low humm and medium to high pitched buzz in this computer monitor? [closed]
I recently bought a ten year old 10-bit color fidelity computer monitor (NEC PA301W) that has brilliant display quality but to my sensitive ears has an audible/annoying low pitched humm noise along ...
- 515
0
votes
1
answer
426
views
I was trying to make this circuit on Proteus but this error appears
I was trying to make this circuit in Proteus as you can see but
"[SPICE] transient GMIN stepping at time=3.12737e-007"
error keeps appearing. How do I make this error go away?
2
votes
2
answers
586
views
I need guidance on designing a 2 kV capacitor charging circuit
I have to design high voltage circuit for the first time in my life.
Its purpose is to provide enough voltage to make a spark plug ignite a coal powder mixture.
There are some requirements for this ...
- 115
0
votes
0
answers
503
views
Simple RC circuit connected to Transformer
I am trying to understand about RC circuits and am having confusion understanding power out of the secondary on an ignition coil with a simple RC circuit as load. The output of the secondary coil is ...
- 77
0
votes
0
answers
41
views
Need some suggestion on 220 - 3.3 volt 500 mA power supply (Or 12 volts maximum)
I was planning to make some 220-3.3 volts,5 volts & 12 volts power supplies. I tried the configuration above in proteus (0.47uF, 275 volts RMS, Polypropylene film capacitor in series with a small ...
- 2,519
0
votes
1
answer
56
views
about the high voltage capacitor found in charger circuit
A while ago i have opened an electronic balance charger for a reason to try understanding how the circuit works so I've drawn the entire circuit for that purpose but i no longer have the drawing, but ...
user270262
1
vote
1
answer
896
views
I have a problem with capacitor discharge in an ignition circuit CDI
I have a hard time understanding what the problem in this circuit is, can someone help please?
I have a Moped with its capacitor discharge ignition box. It works fine, the spark exist, but I want to ...
user270262
0
votes
1
answer
547
views
Eliminate transient loss of power due to inverter (UPS) transfer time
I have a 120V AV receiver (amplifier) connected to a step down transformer for converting from 230V mains. This is the only electronic equipment in my home to completely lose power and turn off/on ...
- 167
1
vote
2
answers
658
views
Reduce voltage from transformer [closed]
I am trying to build a variable power supply using a transformer with a 12V 0 12V - 5 ampere output. I am using a BR1010 rectifier. I have connected the 2 - 12V wires from the transformer to the AC ...
- 25
2
votes
2
answers
207
views
Can transformers be used to adjust capacitors?
It seems capacitors are subject to a "quality triangle", where we can only pick two out of three desirable traits:
High voltage rating
High capacitance
Cheap
For example, a high-voltage high-...
- 238
0
votes
1
answer
111
views
Capacitor Shorting in transformer circuit
I built the circuit shown in the link with 240v
https://www.instructables.com/id/Variable-voltage-ignition-coil-power-supply/
It did not work (produceing no spark), as I believe my capacitor was ...
- 17
20
votes
2
answers
3k
views
Power supply - purpose of the capacitor on the side of the transformer before full bridge rectifier
I was wondering if someone can explain the purpose of the capacitor C1141 from the attached picture. I know that C1142 is a filter cap: that much is obvious to me. However, I can't seem to grasp the ...
- 301
-2
votes
1
answer
155
views
Building a HV transformer
I built this circuit recently though it did not work for me
https://www.instructables.com/id/Variable-voltage-ignition-coil-power-supply/
Using this coil
https://www.autosurplus.com.au/brand/...
- 17
0
votes
1
answer
112
views
Coil Damage Worries [duplicate]
I was trying to make a hv generator from an ignition coil. I bought one from the local mechanics, and put it in a circuit in series with a capacitor and a light dimmer connected to mains 240v. The ...
- 90
14
votes
2
answers
5k
views
What is the purpose of putting a capacitor on the primary side of a step-down transformer?
I'm looking at this design
For a split supply. I get that the thermistors are there to limit the inrush current, but I don't understand the purpose of C9 and how its value was chosen.
- 433
0
votes
2
answers
2k
views
How does this simple FM slope detector work?
I understand what happens from the diode onwards, it's a rectifying amp and a low pass filter that filters any unwanted frequencies from the carrier, but what is going on in terms of voltage between ...
0
votes
2
answers
640
views
Transformer open secondary
In the circuit provided by the link, would having an open secondary coil (not having it connected to any ground) damage the it? The coil is connected to pulsed 240v ac at 50hz. If it is not arcing, (...
- 90
1
vote
1
answer
745
views
Why Current draw in DC variable power supply is not sizable?
I have done a DC variable power supply, and checked it using multimeter the output voltage ranges from 1.3v to 19v, but the problem is when I added a DC load(small DC motor) it was not working, why?
...
0
votes
1
answer
284
views
Ignition coil HV power supply damage?
I recently built a HV power supply, as per the link (using a pencil ignition coil). However, I used a capacitor of around 5nf, which meant the supply did not work. The capacitor reduced the amps too ...
- 90
0
votes
1
answer
43
views
Transformer duality model with capacitor
I want to know if it is possible to transfer power through the instruments using capacitors? As you know instruments such as Marx generator actually increase the power but we aim to have sth to work ...
1
vote
1
answer
85
views
Question about equation for LT3750 capacitor charger IC
I have a question about the equation for minimum primary inductance on page 8 of the data sheet for the LT3750 high voltage capacitor charging IC.
The equation in question:
$$L_{\text{pri}} \geq \...
3
votes
3
answers
715
views
Analysis of a circuit with transformer, R and C components
I am not able to solve the above problem. I don't think my equations are wrong but I am not able to solve them. Please help me with this.
The answer given in my workbook is 3.93cost(3t+59.9)
Method A
...
- 545
1
vote
3
answers
50
views
Get 1,5U voltage on the transformer
I have a transformer with a midpoint that gives a voltage of 1U at the ends of its secondary winding. Can I, using only capacitors and diodes get a DC voltage of about 1.5U (but less than 2U)? If so, ...
- 11
3
votes
1
answer
1k
views
Transformer vs capacitive vs both coupling to speaker
I have seen various configurations in my lifetime on how an 8-ohm output speaker is connected to amplifier circuits.
Currently I'm doing a project using an LM386 amplifier and I capacitor coupled ...
0
votes
3
answers
1k
views
High Voltage (3,000V) Capacitor Charging Circuit Needed
I need help in designing a capacitor-charging circuit that will accomplish the following: charge a 3,000V/200uF capacitor from a 37V battery. The desired charge time is 5 seconds. The battery is a ...
- 9
0
votes
2
answers
1k
views
How to fast charge capacitor 2200uF/400v in fewer seconds?
I have a problem to charge a capacitor 2200uF/400v. It takes 30 second to reach 300v. I hope can reach 300v in 10 seconds. thanks :)
This my schematic:
0
votes
2
answers
939
views
Need help DC biasing an AC source
I am trying to simulate this circuit I saw here:
However, when I simulate it, the "mid-point" does not behave like the blue line in the above picture. You can check the simulation here:
Is the ...
- 471
-1
votes
2
answers
95
views
In this current therapy circuit design how to reduce output current [closed]
Here, I plan to switching two N-type MOSFET by using 12 V step up center tap transformer (1:10). My output is around 120 Vac. Its great but the current is nearly 17.5 A. How can I reduce the current ...
- 1
6
votes
1
answer
28k
views
How to determine the electrolytic capacitor polarity from PCB printings?
I have this PCB board that I need to solder a capacitor to it.
This is the board:
And I'm not sure where should I solder the negative and where the positive.
Can someone please explain what this ...
- 127