gimmik capacitors and gimmik transformers - Page 1
Forum section: electronics / beginners

author: robowaffe
author_rank: Regular Contributor
timestamp: July 29, 2023, 11:06:26 am
content: so gimmik capacitors are 2 stub wires twisted together.and they are about 1 picofarad depending on how long they are.A gimmik transformer would be 2 wires twisted together but using both ends of each side for a 1:1 isolation transformer.What is the henries of a gimmik transformer?

author: xavier60
author_rank: Super Contributor
timestamp: July 29, 2023, 11:40:47 am
content: 2.99e-8 H,from this calculator,https://www.eeweb.com/tools/loop-inductance/

author: robowaffe
author_rank: Regular Contributor
timestamp: July 29, 2023, 11:43:35 am
content: Thats much less than wire inductance.But how come the diagram on that page only has 1 wire on it, isnt there 2 wires in a transformer?

author: xavier60
author_rank: Super Contributor
timestamp: July 29, 2023, 11:49:33 am
content: Quote from: robowaffe on July 29, 2023, 11:43:35 amIt calculates the inductance of a single loop of wire. The inductance will be the same for each primary and secondary loop of a transformer.

author: robowaffe
author_rank: Regular Contributor
timestamp: July 29, 2023, 11:52:39 am
content: So if u did around a 2cm iron coin?

author: xavier60
author_rank: Super Contributor
timestamp: July 29, 2023, 11:58:57 am
content: Quote from: robowaffe on July 29, 2023, 11:52:39 amI don't know for certain, but I don't think it would work well due to core losses. One turn of that size on a ferrite core would work ok at low voltage at tens of KHz. It's difficult to be specific.

author: robowaffe
author_rank: Regular Contributor
timestamp: July 29, 2023, 12:12:41 pm
content: I don't need 100% power to go through, but at least 50% would be nice.So what are these core losses? Or coin losses in this case?Does that mean its the henries that go down, or is it more indemic loss than that?

author: xavier60
author_rank: Super Contributor
timestamp: July 29, 2023, 12:23:25 pm
content: Quote from: robowaffe on July 29, 2023, 12:12:41 pmI dont know enough to say anything too useful for now. Im expecting some 36mm ferrite pot cores to arrive soon for some experiments. I could report back then.

author: robowaffe
author_rank: Regular Contributor
timestamp: July 29, 2023, 12:25:19 pm
content: cool. I looked it up, and core losses happen at higher voltages, so if I do my system at low voltage its got a chance at workin'.Thanks for the information, Xavier60.

author: Zero999
author_rank: Super Contributor
timestamp: July 29, 2023, 03:08:49 pm
content: It's flux density and frequency which affect core losses, not voltage.

author: robowaffe
author_rank: Regular Contributor
timestamp: July 29, 2023, 03:26:31 pm
content: that is the exact opposite of what I just read.that would mean it just lowers the Henry's!!!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 29, 2023, 08:04:46 pm
content: An iron coin would block field, at any frequencies where such a structure would be meaningful (100s MHz). That is, it looks like a slug of moderate-resistance metal.Bulk iron is a very poor core material at anything above DC.A ferrite core might give reasonable function down to say 100s of kHz, depending on core size and circuit impedance.Tim

author: robowaffe
author_rank: Regular Contributor
timestamp: July 30, 2023, 05:33:24 am
content: Isn't the slower a transformer (hz wise) can function the better the material is?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 30, 2023, 06:11:01 am
content: In a sense, perhaps. But there are many ways in which something can be "better", it's not a one-variable system.Tim

author: xavier60
author_rank: Super Contributor
timestamp: July 31, 2023, 12:42:33 am
content: Second try,This is an attempt at 1.5V into 1 turn on a 36mm PC40 pot core at 50KHz. The current waveform was measured across a 0.1Ω shunt, about 0.8A.I calculate ~9uH. In a separate test, the core saturates at 5A.From what arrived, the cores are sold in sets,https://www.aliexpress.com/item/1975838620.html?spm=a2g0o.productlist.main.1.2f401f8bMJBNPS&algo_pvid=55a5bf3e-5a17-44a1-8cfb-1350986a8ae7&algo_exp_id=55a5bf3e-5a17-44a1-8cfb-1350986a8ae7-0&pdp_npi=3%40dis%21AUD%213.06%213.06%21%21%212.02%21%21%402101f49816907717404235559e94f7%2112000026915788036%21sea%21AU%21130254308&curPageLogUid=9aSY9FuasQuY

author: Terry Bites
author_rank: Super Contributor
timestamp: July 31, 2023, 07:04:07 am
content: Get to grips with the transformer equation:For sine wave transformer Bmax is the maximum allowed flux before core saturation.E=4.44 f N A Bmax pi()*sqrt(2) = 4.44A =E/4.44 f N BmaxA= cross sectional Area of coreE = emfN=Turnsf= frequencyB= Flux density

author: robowaffe
author_rank: Regular Contributor
timestamp: July 31, 2023, 07:45:04 am
content: So at 50 gigahertz, the transformer i need is a million times smaller than the one demonstrated here.