How To Learn Random Things?

[KMcB12345]

Build Random Things...

The problem is quite simple. Do to a mental problem/lack of faith, I have a decreased level of creativity. Electronics is something that intrigues me. My main interest is in FM transmission. I know FM is a rather advanced topic but it is still something I wish to master.

I have recently developed seizures (recently meaning over 6 months ago). I have been having memory lapses. I forgot that my cousin came down for a month, and I forgot that I went to the zoo on mothers day with my sister. Point is I have a fear that I may have forgotten what has been taught to me at school.

I am hoping to study the books they have gave me and put my knowledge to work. I have a toolkit with a variety of parts. I however do not have a clue how to test my knowledge without an oscilloscope, and an adjustable voltage providing machine (whose name escapes me). However, I do have a multi-meter.

I guess for the start I could build an adjustable voltage providing circuit. The power rating would probably be very low. The idea I just now created would involve a potentiometer. The potentiometer would be a voltage divider. I could use the multi-meter to check the voltage being offered. When the voltage is the value I wish it to be I would then connect it to the circuit needing to be powered.

What about the power ratings?
What if I have a circuit that needs a certain voltage and a specific power rating?

Anyways, my current task:
Right now, I am trying to build a circuit that ITT Tech provided:
https://electroschematics.com/83/mini-fm-transmitter-max2606/

The problem:
I don't have any RCA jacks nor do I know what RCA jacks are used for. I think it is used for a microphone or some sort of music provider?
Is there anyway I could create a tone/pulse generator and basically probe a signal out?

 

[cr0sh]

Build Random Things...

The problem is quite simple. Do to a mental problem/lack of faith, I have a decreased level of creativity. Electronics is something that intrigues me. My main interest is in FM transmission. I know FM is a rather advanced topic but it is still something I wish to master.

I have recently developed seizures (recently meaning over 6 months ago). I have been having memory lapses. I forgot that my cousin came down for a month, and I forgot that I went to the zoo on mothers day with my sister. Point is I have a fear that I may have forgotten what has been taught to me at school.

First off - you have my sympathy; I can't imagine what you are going through and how it is affecting you day to day, etc. Trying to work with electronics while "fully functioning" can be interesting at times; while having seizures and potentially forgetting things - ooh. I would say your best best is to invest in some notebooks, and take -tons- of detailed notes as you work, perhaps with times and dates, or some other method to organize things; think of these notebooks as your "external memory" (you might try a tablet or a netbook or something - but here's the problem: I don't know anything about your seizures, but if they are something that causes you to collapse or flail any, then an electronic device might not be best; it might not get charged, it might get damaged, it might fall, etc - therefore, pencil/pen and paper would seem to be the better choice).

I am hoping to study the books they have gave me and put my knowledge to work. I have a toolkit with a variety of parts. I however do not have a clue how to test my knowledge without an oscilloscope, and an adjustable voltage providing machine (whose name escapes me). However, I do have a multi-meter.

You are probably thinking of an "adjustable power supply"; you can build such a thing (small scale) fairly easily, with just a multi-meter - an oscilloscope will be needed later for FM, but you probably aren't quite there yet.

I guess for the start I could build an adjustable voltage providing circuit. The power rating would probably be very low. The idea I just now created would involve a potentiometer. The potentiometer would be a voltage divider. I could use the multi-meter to check the voltage being offered. When the voltage is the value I wish it to be I would then connect it to the circuit needing to be powered.

That sounds reasonable; to start out with, you could build a simple linear power supply, with voltage adjustment (you could even do current adjustment, if you wanted), using an LM7805 (for +5 volt output), and a separate LM7812 (+12 volt output); you could make each adjustable - or just use one or the other (depending on the range you want). If you wanted the regulator to supply more current (the standard TO-220 case devices are limited to about 1 amp, with a good heatsink; they do make TO-3 versions, which I think will allow you to go up to 1.5 or 2 amps?), you could use a bypass transistor (see the datasheet for example circuits; there is also a good linear regulator app-note floating around out there by TI, if I remember right).

What about the power ratings?
What if I have a circuit that needs a certain voltage and a specific power rating?

As noted above, you are going to be limited to a certain extent, but with the bypass transistor and a big heatsink (and maybe a fan), plus an input transformer or whatnot to keep things cool enough, you should be able to get up into the 5-7 amp range (I think - homemade power supplies are not my strong suit; others here can give you better advice, I think). At a certain point, though, at your level - you may have to purchase an adjustable bench power supply (which don't come cheap, either - depending on the voltage range and rating you need). The thing is, power supplies can become complicated very quickly; I've got in my shop a couple of small "trainer" style linear power supplies that are adjustable (0-25 volts, 0-2.25 amps), and the circuit is fairly complex (at least to my inexperienced eyes); a switching regulator circuit would likely be even more complicated.

Also - depending on your needs - you might think about modding a PC power supply; not very adjustable, but it could be a cheap solution (unfortunately, for a lot of electronics work, especially experimentation, you kinda want a way to limit the current, and the voltage - you can't do either easily with a PC power supply).

Anyways, my current task:
Right now, I am trying to build a circuit that ITT Tech provided:
https://electroschematics.com/83/mini-fm-transmitter-max2606/

That's a fairly simple circuit; I would wonder though if you would need an oscilloscope, among other test equipment for it to "tune it" (maybe not; I'm not seeing any IF stages or anything - everything is done "on-chip" I think). Generally with RF you also want things like a frequency counter and the signal generator (with the bandwidth for the kind of signals you expect to work with); but this circuit seems pretty self-contained. Probably an o-scope to check the final output would be all that would be necessary (though how you would measure FM without needing something like a 500 MHz scope - I'm not sure; I've never dealt with such frequencies before).

The problem:
I don't have any RCA jacks nor do I know what RCA jacks are used for. I think it is used for a microphone or some sort of music provider?
Is there anyway I could create a tone/pulse generator and basically probe a signal out?

RCA Plugs and Jacks: https://en.wikipedia.org/wiki/RCA_connector

Hope that helps - good luck, and maybe others will chime-in here to correct any mis-information I have supplied...

 

[ronv]

My daughter in law has a similar problem that is controlled with drugs. She would have no knowledge of what she did while having the seizure but lost no knowledge learned at other times.
You might consider downloading LTSpice (free). You can then practice your circuits without actually building them. I find is very satisfying but sometimes miss the smoke.

 

[KMcB12345]

Thank you very much for the replies. My seizures seem to be controlled by a medicine as well. I used to run around uncontrollably (remembering only what I see) and then freeze up. Now, I just freeze up, although that has seemed to stop. I haven't had one in about a week, do to the new medicine they have me on.

I have Multisim and LTSpice installed. I am not sure one could build a FM transmitter using the programs and test it somehow on the computer. Then again, I need to learn a lot of things before I even try. I will start using Multisim for now.

I will practice note-taking. I believe I didn't take any notes going through college. I just sort-of underlined things in the book. The teacher kept saying 'you'll never remember what I teach you but everything I am teaching you is in the book. So, just keep your books nearby.' I'll practice note-taking by taking notes from the books that I have and the books from ITT's virtual library.

"adjustable power supply" - Yes! That is it. I wish to build one of those. A simple linear power supply, with voltage (and current) adjustment. You have given me quite a number of ideas and help. Thank you.

I have a LM7805 that I need to set up and that circuit will be complete. I haven't really looked over the schematic so, I don't know how this circuit actually works. Setting up the LM7805 shouldn't be a problem, but I'll just focus on the notes for now.

I now know what RCA jacks are. I have a PlayStation 2 connector that I can hook that up to it and listen to the output on a radio.


I plan to do a great deal of studying while my 5 day EEG test imprisonment is happening. It should be happening in a week or two. They will put a weird helmet on me and videotape my every movement. Oh well, it "needs to be done," as the doctor put it. The medicine is working, leave me alone. Ah... might as well.

 

[WTP Pepper]

Sorry to hear about your issues. Must be so difficult, but I think the basics of FM has rarely changed over my 25 years in the industry. From the Foster Seeley discriminator to slope detectors.

I agree with ronv. LTSpice is a superb program that lets you understand what's going on with only lifting the finger on a mouse. It may take a bit to understand the program, but it won't be long before it makes sense. Chin up!

All the best to you for trying!

 

[duffy]

The problem is quite simple. Do to a mental problem/lack of faith, I have a decreased level of creativity.

There's an app for that -
https://ideagenerator.creativitygames.net/