Skip to main content

Questions tagged [toroid]

A toroid is a donut shaped transformer or inductor with a core made of ferrite, permalloy or wrapped silicon steel. They are used where better efficiency, containment and isolation of EMI are very important. A conductor must pass through the center of the toroid to count as a 'turn'.

Filter by
Sorted by
Tagged with
2 votes
0 answers
70 views

Centre tapped transformer outputting uneven voltages, have I damaged it?

I am modifying a KEF PSW 2010 amplifier board to make it run cooler. The mod involves removing voltage dropper resistors on the input to the L7815 and L7915 regulators (+15V and -15V) and replacing ...
David Fear's user avatar
3 votes
1 answer
104 views

"Toroidal transformer action in the presence of total B field confinement" (?!) Is Wikipedia wrong?

Wikipedia has an article about toroidal transformers and inductors. It is well known that an ideal toroidally wound coil has total magnetic field confinement due to symmetry in the case where the ...
Math Keeps Me Busy's user avatar
4 votes
1 answer
154 views

Boost Inductor Design for three phase Diode Bridge Rectifier for PFC operation

I am doing a simple DCM based control for power factor correction. Please see the topology below . Specifications are as below: 1.) Power 5KW 2.) Input Voltage is 415V L-L Nominal 3.) Inductor ...
Archit Asthana's user avatar
1 vote
1 answer
55 views

Constructing an AC clamp ammeter

How many turns needed on a donut ferrite core to produce 5 volts when one conductor of a 240 volt AC cable is threaded through it? What size of ferrite should I use and what diameter of wire?. I'll ...
Silvosa's user avatar
  • 25
6 votes
2 answers
551 views

RF transformer design rules

I am reading a book about building a HF transceiver. This book gives instruction about how to build, but not so much about the theory behind. In particular, I am exploring the following balanced ...
Enrico's user avatar
  • 561
1 vote
0 answers
223 views

Toroidal coil as current sensor

Is there a simple way to estimate the amount of flux that is caught by a toroid coil (filled by some core material, like powder iron for example), which surrounds a straight wire with a current ...
oliver's user avatar
  • 783
0 votes
1 answer
184 views

How to measure power consumption of a lot of circuits?

Our house has a lot of electrical circuits/breakers and I have thought about how nice it would be to be able to monitor current consumption for each of them in parallel. Of course one can buy meters ...
oliver's user avatar
  • 783
5 votes
2 answers
376 views

Toroid inductor correction factor

Various equations and online calculators for the inductance of a wound toroid only include a parameter for the number of turns, not how the turns are wound (example). But the answer to this question, ...
hotpaw2's user avatar
  • 4,811
2 votes
2 answers
160 views

Variance in winding a toroid

I'm building a filter from a kit with some given (microscopic pre-soldered SMT) capacitors and 2 toroids. It looks like the notch frequency is a bit too low with 10 wire turns around a T37-2 iron ...
hotpaw2's user avatar
  • 4,811
2 votes
1 answer
170 views

What is going on regarding power toroid shielding? (some shielded, some unshielded, no apparent difference)

In this Digikey search for 47uH toroid inductors, the shielding column shows that some are considered shielded, and others are considered unshielded. And even from the same manufacturer (Bourns). A ...
MicroservicesOnDDD's user avatar
0 votes
0 answers
143 views

Inductor Datasheet (Inductance No DC)

Can anyone please help me understand what is Inductance (Typical) and Inductance No DC in the datasheet of inductors from Pulse Electronics? The link for datasheet for toroid inductors of Pulse ...
SGhosh's user avatar
  • 1
0 votes
2 answers
235 views

Difference between open and closed center toroid transformer

I just want to know, what is the difference between open center and closed center toroidal transformer. Open center meaning the toroid has a metal rod in the middle while the open center doesn't have ...
Roger Dsuza's user avatar
0 votes
0 answers
51 views

Toroid core transformer: consequences of doubling the number of turns

In a 2N3904 common emitter RF amplifier circuit that I am building, the designer uses a FT37-43 miniature core with an 8 turns primary : 2 turns secondary ratio to couple to the next stage. I ...
LevelUpEELab's user avatar
0 votes
1 answer
216 views

Return path magnetic field on hall effect current sensor

We would like to use a toroid core and hall effect sensor shown in the figure below for measuring current in an Electric Vehicle from a battery pack. Questions are: Would placing the wire carrying ...
EarthLord's user avatar
  • 565
0 votes
1 answer
110 views

Inductor dimensions as a function of time(?)

While perusing the text book "Foundations of Analog and Digital Electronic Circuits" by Anant Agarwal , I came across this text in the section on inductors: Why are the dimensions of the ...
jrive's user avatar
  • 639
0 votes
1 answer
100 views

Preventing my amplifier from being fried again and using diodes

I'm experimenting with sending different signals through different toroidal coil windings, I also place a ball compass in the center to see the type of rotation it creates. I would like to prevent ...
Rick T's user avatar
  • 205
1 vote
1 answer
3k views

Calculating the number of turns for my inductor

so i've calculated that I need an inductance of 0.150mH for my inductor. However, I'm trying to figure out the number of turns I need for it. # I've got an answer of 24 turns but this doesn't feel ...
Q.T.π's user avatar
  • 33
9 votes
5 answers
3k views

Why do toroid inductors have a square cross-section?

What is the reason behind the square cross-section of most toroid inductor cores? Correct me if I am wrong, but would not a circular cross-section give the lowest resistance since it has the smallest ...
Beacon of Wierd's user avatar
2 votes
1 answer
2k views

Mains transformer blew up amplifier, incorrect description in wiring instructions?

I am assembling a power amplifier from a kit I purchased from Velleman (Module: VM100). With the amplifier I purchased this mains toroidal transformer - . The amplifier came with these instructions: ...
Harley Morlet's user avatar
0 votes
1 answer
590 views

DIY toroidal transformer spot welder

I've put together a toroidal transformer using a core suitable for 1500VA. The primary coil is around 70 turns with the secondary coil being just one. When I plug it into the mains (110VAC), I just ...
Chris's user avatar
  • 59
12 votes
2 answers
9k views

Ferrite vs. iron powder toroid for buck converters?

I'm wondering about the difference between small (13 mm outer diameter) ferrite and the yellow white iron powder toroids. Will the ferrite toroids saturate at 5 A current? I'm planning on using ...
Indraneel's user avatar
  • 2,177
2 votes
2 answers
523 views

Primary current expectation in unloaded toroidal transformer

Background I found a hefty, 7 kg toroidal transformer in visually good condition at a flea market which I am trying to map out. This is part one: I am not sure about what is happening on the primary ...
pipe's user avatar
  • 14.4k
2 votes
1 answer
283 views

DIY transformer (toroid) waveform

Update Ok, it may be related to the adhesive I'm using to glue the toroids on the 3D prints.. I'll wait till tomorrow for it to cure and test again.. I'm trying to build a portable/battery ...
Wesley Lee's user avatar
  • 7,924
0 votes
1 answer
159 views

Toroid coating got scratched

Will there be any performance effect if the torroid coating gets scratched?
Hrituraj Singha Roy's user avatar
1 vote
1 answer
377 views

How to choose Toroid core to improve DC current measurement

I'm currently working on a project where I'm using a linear Hall-Effect sensor to monitor changes in DC current. This DC current is modulated at anywhere from 15 to 20 Hz. The magnitude is around ...
Dwayne Reid's user avatar
  • 23.9k
0 votes
2 answers
322 views

Inductance of a closely wound toroidal coil

"The qualification that the coil should be closely wound on the toroid is to minimize the linkage flux around the individual turns of wire." What does "the linkage flux around the ...
user168855's user avatar