HELP, I need a transformer - Page 1
Forum section: electronics / general

author: snipersquad100
author_rank: Frequent Contributor
timestamp: December 05, 2013, 09:15:47 pm
content: Can anyone please point me to a transformer for this ESR meter project.

author: c4757p
author_rank: Super Contributor
timestamp: December 05, 2013, 09:20:31 pm
content: The turns ratio is given because they intend you to wind it yourself.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: December 05, 2013, 09:24:19 pm
content: Has it goto be in a bobbin?

author: c4757p
author_rank: Super Contributor
timestamp: December 05, 2013, 09:26:54 pm
content: Look up the core they have specified and try to find a similar one. (I don't have time to check ATM.) A small ferrite toroid would probably do, though 400 turns on a small toroid would be a bitch.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: December 05, 2013, 09:53:23 pm
content: yeh, use the thinnest gauge wire I can find lol

author: Bored@Work
author_rank: Super Contributor
timestamp: December 05, 2013, 09:54:38 pm
content: Amidon cores are still available. A simple google of the product number will tell you.

author: kg4arn
author_rank: Unknown
timestamp: December 05, 2013, 10:01:17 pm
content: If you trust the design, I recommend using the exact core the designer has specified.Switching cores requires that you have a good knowledge of what you are doing: frequency range, core losses, saturation. . .

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: December 05, 2013, 10:10:25 pm
content: Hi,I built one of those a while ago and found that a transformer from one of those CFL's was the same ratioThere using a transformer to ensure the impedance driving the capacitor is as low as possible.Also it says 400:20, so would'nt any 20:1 transformer work

author: snipersquad100
author_rank: Frequent Contributor
timestamp: December 05, 2013, 10:19:31 pm
content: Thanks smilly, i think the ratio has something to do with the current handling, not sure thou.

author: Icarus
author_rank: Regular Contributor
timestamp: December 05, 2013, 11:30:16 pm
content: Maybe you can use E13/7/4. Its tiny and much more easier wind than a toroid.I strongly recommend to use bifiliar or trifilar winding. That'll reduce the skin effect.

author: Bored@Work
author_rank: Super Contributor
timestamp: December 05, 2013, 11:34:41 pm
content: Quote from: Icarus on December 05, 2013, 11:30:16 pmThere is only one problem with this theory. The core in question is an E core, not a toroid. Available for $2.50.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: December 05, 2013, 11:40:50 pm
content: To the OP, snipersquad100,Do you your mind set on building this ESR meter?I have started two threads on ESR meters that do not need a transformer.This is analog one similar to the one you looking at:https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/msg171364/#msg171364This one can be used with a DMM to get a digital readout:https://www.eevblog.com/forum/projects/esr-meter-adapter-design-and-construction/msg341177/#msg341177Regards,Jay_Diddy_B

author: snipersquad100
author_rank: Frequent Contributor
timestamp: December 06, 2013, 12:01:58 am
content: The esr meter im interested is this oneHe modified the schematic to work with arduino.Im only building it for fun, I don't expect it to be highly accurate.

author: at2marty
author_rank: Regular Contributor
timestamp: December 20, 2013, 10:50:28 pm
content: I'm currently working on one that is based off of the same video. The modifications that I made were to make it "stand alone" rather than a shield that goes on an Arduino. I also added in serial port capability for debugging and an ISP header for programming modifications. I also re-wrote the source code in plain C.The transformer that I selected is an audio transformer available from Radio Shack part number 273-1380. I believe that it will work correctly, though it's a bit tall and will be close when I mount everything into the enclosure.I just ordered some boards and should have them next week. Once I do some testing to make sure that it works the way that I anticipate, I will gladly release the source code and the design files. I used EagleCad for the schematic and board layout.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: December 26, 2013, 07:58:48 pm
content: hi at2martyAny luck with your esr meter?

author: snipersquad100
author_rank: Frequent Contributor
timestamp: January 04, 2014, 12:35:20 pm
content: Cant get any voltage out of c2, im using a 10uf cap. theres 2.5v going in but nothing going out to the transformer.