sci.electronics.design

Started by Glenn in sci.electronics.design8 years ago 2 replies

Read a little about isolated Cuk converters. Why are they not used instead of Buck, boost, Buck-boost converters? They work best with CCM but...

Read a little about isolated Cuk converters. Why are they not used instead of Buck, boost, Buck-boost converters? They work best with CCM but can of cause also use DCM. The original patents are expired: http://boostbuck.com/TheFourTopologies.html The 1:1 transformer is gapless. The input/output-transformer must have a gap: http://www.boostbuck.com/IsolationoftheCukConverter.html http:/...


Trying to Get Less Leakage and Picture Link of Transformer

Started by D from BC in sci.electronics.design10 years ago 7 replies

Here's a 1:1 transformer I made. http://www.members.shaw.ca/chainsaw/SED/xformer2.JPG 1.4MB Materials EFD cores Coax cable Ignore the...

Here's a 1:1 transformer I made. http://www.members.shaw.ca/chainsaw/SED/xformer2.JPG 1.4MB Materials EFD cores Coax cable Ignore the purple wire. Primary inductance: 200uH@700khz Leakage inductance: 220nH@1Mhz I want less leakage. 22nH or less leakage would be nice. I figure in order to reduce the leakage I need to get my secondary and primary closer together. iows I need coa...


DC transformer, x-Chapters 9x.16

Started by Winfield Hill in sci.electronics.design2 years ago 16 replies

x-Chapters 9x.16, about DC transformers, AKA bus converters. It's a synchronous dc-dc converter, with in/out voltage ratio set by a fixed...

x-Chapters 9x.16, about DC transformers, AKA bus converters. It's a synchronous dc-dc converter, with in/out voltage ratio set by a fixed switching duty cycle. Like ac transformers, they transfer power in either direction, as a function of who's above the ratio. The current-ratio also obeys the voltage-ratio rule, like an ac transformer. As bus-converters, they're used to conver...


Switching current limiter for safe charging of large capacitors, and short circuit protection

Started by P E Schoen in sci.electronics.design9 years ago 26 replies

In a previous post about minimizing spikes on a square wave push-pull=20 transformer drive, my simulations discovered a very large and...

In a previous post about minimizing spikes on a square wave push-pull=20 transformer drive, my simulations discovered a very large and probably=20 destructive current surge due to the large capacitor load on the output = of=20 the step-up transformer and FWB. I proposed using a brute force linear=20 current regulator, but the SOA of the transistors would be exceeded. I = need=20 an output o...


Help crossing a Minicircuits RF transformer to Coilccraft.

Started by amdx in sci.electronics.design4 years ago 2 replies

I'm building a circuit that specifies a Minicircuits T1-1T-X65 Rf transformer, > ...

I'm building a circuit that specifies a Minicircuits T1-1T-X65 Rf transformer, > https://www.minicircuits.com/WebStore/dashboardPdf?model=T1-1T-X65 Because of price and ease of purchase I wonder if I can sub this Coilcraft part, > https://www.mouser.com/datasheet/2/597/swb-1223867.pdf I'm confused by the Minicircuits 50 ohm spec, totally missing on the Coilcraft page. Coilcraft gi


In The Ever lasting Chain Of Experiments The Next Project, ultrasonics part 12

Started by Jan Panteltje in sci.electronics.design6 years ago

In The Ever lasting Chain Of Experiments The Next Project, ultrasonic anti-fouling for boats. Part 14 The transformer core I...

In The Ever lasting Chain Of Experiments The Next Project, ultrasonic anti-fouling for boats. Part 14 The transformer core I ordered from ebay arrived, wound the new bigger transformer today: http://panteltje.com/pub/ultrasonic_antifouling_bigger_transformer_IMG_5179.JPG that is 2 x 6 turns bifilair primary and 4 x 30 turns secondary. That core should be good to 120 VA. Ma...


How do you calculate the REQUIRED voltage from a transformer secondary

Started by Anonymous in sci.electronics.design5 years ago 30 replies

How do you calculate the REQUIRED voltage from a transformer secondary? Ok, here's the plan. A friend of mine installed a bunch of LED...

How do you calculate the REQUIRED voltage from a transformer secondary? Ok, here's the plan. A friend of mine installed a bunch of LED fixtures to run off a solar panel and a 12V marine battery. It's drawing about 15amps at 12VDC. It works fine when the sun is shining, but drains the battery when there is no sun. He said he gets tires of having to hook a battery charger to that battery ...


SMPS Cuk converters

Started by Glenn in sci.electronics.design8 years ago 1 reply

Read a little about isolated Cuk converters. Why are they not used instead of Buck, boost, Buck-boost converters? They work best with CCM but...

Read a little about isolated Cuk converters. Why are they not used instead of Buck, boost, Buck-boost converters? They work best with CCM but can of cause also use DCM. The original patents are expired: http://boostbuck.com/TheFourTopologies.html The 1:1 transformer is gapless. The input/output-transformer must have a gap: http://www.boostbuck.com/IsolationoftheCukConverter.html htt...


SMPS Cuk converters

Started by Glenn in sci.electronics.design8 years ago 1 reply

Read a little about isolated Cuk converters. Why are they not used instead of Buck, boost, Buck-boost converters? They work best with CCM but...

Read a little about isolated Cuk converters. Why are they not used instead of Buck, boost, Buck-boost converters? They work best with CCM but can of cause also use DCM. The original patents are expired: http://boostbuck.com/TheFourTopologies.html The 1:1 transformer is gapless. The input/output-transformer must have a gap: http://www.boostbuck.com/IsolationoftheCukConverter.html http:/...


The 4 times rule for matching transformer impedance

Started by amdx in sci.electronics.design7 years ago 21 replies

Hi all, I have always heard and used the 4 times rule for the impedance of a transformer winding. Example; To match 50 ohms to 400 ohms,...

Hi all, I have always heard and used the 4 times rule for the impedance of a transformer winding. Example; To match 50 ohms to 400 ohms, the primary inductance should be 200 ohms at the lowest frequency of interest. 4 x 50 = 200 ohms XL. Tonight I'm searching for a reference for the 4 times. I found this; http://www.scribd.com/doc/116333646/The-Four-Times-the-Impedance-Rule-for-Br...


Mains wiring question: Sizing buck-boost transformer?

Started by Gary Walters in sci.electronics.design9 years ago 35 replies

In USA. Source: 208v, 60 hz, 2-wire (2 phases from 3 phase "Y" supply). Load: 240v, 20A. I presumed that sizing a buck-boost transformer...

In USA. Source: 208v, 60 hz, 2-wire (2 phases from 3 phase "Y" supply). Load: 240v, 20A. I presumed that sizing a buck-boost transformer is simple KVA math (source volts * load amps). But... This PDF document: on the last page says: - - - "An example of an everyday application is always a good way to explain the intent of t


Oscillator running on home made thermocouple

Started by Jan Panteltje in sci.electronics.design9 years ago 10 replies

Oscillator running on home made thermocouple: http://www.youtube.com/watch?v=yu0IXX6OXtY&feature=youtu.be I did some transformer winding and...

Oscillator running on home made thermocouple: http://www.youtube.com/watch?v=yu0IXX6OXtY&feature=youtu.be I did some transformer winding and some soldering. The thermocouple is made with simple resistance wire (conrad 543-074-12) 100 Ohm / meter, soldered against normal coper transformer wire. this makes a type 'T' thermocouple, although my calculation show it should then give 18.342767 m...


Identifying buck-boost transformer windings?

Started by DaveC in sci.electronics.design8 years ago 19 replies

Imagine you are asked to install a used buck-boost transformer. Imagine you could normally do this in a few minutes. Except if the leads were...

Imagine you are asked to install a used buck-boost transformer. Imagine you could normally do this in a few minutes. Except if the leads were cut short such that identifying characters on the leads' insulation were missing. Identifying 2 leads belonging to any one winding is straightforward ohm meter work. Maybe use of a ESR meter might help separate the X windings from the H windings?...


transformer core cross section variance

Started by Jamie M in sci.electronics.design10 years ago 2 replies

Hi, I was working on a design for a fullbridge driven ferrite transformer with a 300:1 turns ratio, and I'd like to do both primary and...

Hi, I was working on a design for a fullbridge driven ferrite transformer with a 300:1 turns ratio, and I'd like to do both primary and secondary coils with a single layer (primary 170V/15A, secondary ~50kV/50mA). If I use 10 turns on the primary this would require 3000 turns on the secondary, which is too much for a single layer, so I was wondering if I used a molded ferrite core that ha...


Bifilar Wound Balun Transformer

Started by rickman in sci.electronics.design9 years ago 63 replies

I am learning a bit about antenna design and one of the references I found talks about coupling the antenna to the feedline with a bifilar...

I am learning a bit about antenna design and one of the references I found talks about coupling the antenna to the feedline with a bifilar wound balun transformer. I dug a bit and although I found any number of references talking about bifilar wound baluns, none explained clearly why it is important to be bifilar wound. Any pointers? Rick


Flyback converter

Started by Patrick Chung in sci.electronics.design8 years ago

Even though some authors presents flyback converter as transformer isolated boost converter, it is more closer to reality that flyback dc-dc...

Even though some authors presents flyback converter as transformer isolated boost converter, it is more closer to reality that flyback dc-dc converter can be explained as transformer isolated buck-boost converter. Read more: http://www.cirvirlab.com/index.php/switching-mode-power-supply/132-flyback-dc-dc-converter-basic s.html Also, simulate flyback converter online on http://www.cirvirl


Question regarding general schematic detail for transformers

Started by Anonymous in sci.electronics.design7 years ago 21 replies

Could some electronics guru please help ? Maybe this is a very silly question, so pardon me. In a schematic, a transformer is generally shown...

Could some electronics guru please help ? Maybe this is a very silly question, so pardon me. In a schematic, a transformer is generally shown with 2 -3 parallel bars in the middle to indicate the core. Often, I have seen the parallel bars replaced by a thick, solid bar. So, do the parallel bars represent a laminated core transformer and the thick single bar represent a ferrite core tra...


Rogowski transformer query

Started by Clive Arthur in sci.electronics.design5 years ago 21 replies

If I pass a single wire through a wound air-cored toroid with, say, 1000 turns, then that's a 1000:1 transformer. If, for convenience, I make...

If I pass a single wire through a wound air-cored toroid with, say, 1000 turns, then that's a 1000:1 transformer. If, for convenience, I make it a 1000 turn Rogowski coil and wrap the coil around the single wire, then that's the same. What happens If I wrap the 1000 turn Rogowski coil around the wire twice? My feeling is it that it could be considered as two 500 turn coils in series...


Forward converter is actually transformer isolated buck (step down) converter.

Started by Patrick Chung in sci.electronics.design8 years ago 1 reply

Forward converter is actually transformer isolated buck (step down) converter. Read...

Forward converter is actually transformer isolated buck (step down) converter. Read more: http://www.cirvirlab.com/index.php/switching-mode-power-supply/143-forward-dc-dc-converter-basic s.html Also, simulate forward converter online on http://www.cirvirlab.com/simulation/smps_forward_dc_dc_converter_online.php


unusual crowbar circuit.

Started by Jasen Betts in sci.electronics.design3 years ago 6 replies

Photonicinduction's 50kA transformer. https://www.youtube.com/watch?v=uXEPy6Za6cI -- ?

Photonicinduction's 50kA transformer. https://www.youtube.com/watch?v=uXEPy6Za6cI -- ?