Current - Page 1
Forum section: electronics / projects

author: Jacktron
author_rank: Contributor
timestamp: September 10, 2024, 02:33:20 am
content: How can I convert the amplified voltage here to current? I am trying to create an ac magnetic field using a function generator

author: IanB
author_rank: Super Contributor
timestamp: September 10, 2024, 02:40:45 am
content: Look, I have placed all of your questions in one place for reference.The truth is that what you are asking about is so far beyond your level of understanding and capability, that even if an answer was provided it would not help you.The best advice for you is to stop asking about how to generate an AC magnetic field, and instead try explaining what it is you hope to do with it, if somehow you were to succeed?Tell us your goals. Tell us what problem you are trying to solve?Quote from: Jacktron on September 06, 2024, 11:51:29 pmQuote from: Jacktron on September 07, 2024, 12:03:16 amQuote from: Jacktron on September 07, 2024, 12:48:40 amQuote from: Jacktron on September 07, 2024, 12:49:32 amQuote from: Jacktron on September 07, 2024, 01:08:27 amQuote from: Jacktron on September 07, 2024, 01:39:21 amQuote from: Jacktron on September 09, 2024, 09:13:28 pmQuote from: Jacktron on September 09, 2024, 09:13:28 pmQuote from: Jacktron on September 09, 2024, 09:21:21 pmQuote from: Jacktron on September 10, 2024, 02:24:33 am

author: magic
author_rank: Super Contributor
timestamp: September 10, 2024, 05:02:07 am
content: Hmm, let's try.AC magnetic field + coils + secrecy = over unityUsuallyAs for the question at hand, just google "how to do a current source with an opamp". There is a million examples and application notes.

author: Andy Chee
author_rank: Super Contributor
timestamp: September 10, 2024, 05:22:50 am
content: Your project lacks a lot of detail, without detail we cannot give you detailed nor correct advice.That said, I might begin with a power opamp like the LM1875. It's cheap enough and should be widely available.Build your prototype and test it, take some measurements. And definitely let us know if it blows up!

author: Simon
author_rank: Unknown
timestamp: September 10, 2024, 05:32:29 am
content: Quote from: Jacktron on September 10, 2024, 02:33:20 amThe amplified voltage where ? One look at your schematic tells me that either you have absolutely no clue to the point that you cannot light a light bulb with a battery if you tried so why on earth are you using all those complicated components or you are a batshit crazy conspiracy theorist, and no I have not read any of your other posts that people here allude to.Cease this crap or you will be banned!

author: PGPG
author_rank: Frequent Contributor
timestamp: September 10, 2024, 08:07:20 am
content: Quote from: Jacktron on September 10, 2024, 02:33:20 amIf you want to convert known voltage (V) into proportional to this voltage current (I) then you use resistor (R).The relation between these values is given by V = I x R.Selecting R (resistor resistance) you decide what is the proportionality factor between your voltage and current.

author: Simon
author_rank: Unknown
timestamp: September 10, 2024, 07:39:07 pm
content: Don't bother wasting your time. Have you seen his circuit? no current flows so the question is mute!

author: Zero999
author_rank: Super Contributor
timestamp: September 11, 2024, 12:05:26 pm
content: There needs to be a power supply. Presumably the op-amp's model has one built-in, but the collector of the transistor needs power.Here's an example of a current sink. It demonstrates the fact the op-amp can run off a lower voltage, than the LEDs. A linear regulator such as the LM317L can be used to power the op-amp.

author: Simon
author_rank: Unknown
timestamp: September 11, 2024, 03:34:40 pm
content: why are you feeding the troll? As I said they appear to not understand that any current flows only if there are 2 connections, that is why I said they probably can't light a light bulb. If they can light a light bulb then they are taking the piss with that diagram.

author: Zero999
author_rank: Super Contributor
timestamp: September 11, 2024, 06:52:46 pm
content: Sorry. I didn't realise posting a constant current sink was against the rules. . .In all honesty, I just wanted to upload that circuit, so I can use it in other posts and that someone else might find it useful. Other people will read this, than the original poster.

author: Simon
author_rank: Unknown
timestamp: September 11, 2024, 07:03:38 pm
content: fair enough, I think this one has given up anyway.