Search found 3574 matches
- Tue Jun 19, 2018 3:59 pm
- Forum: General Discussion
- Topic: To evaluate performance of used 18650 cells...
- Replies: 22
- Views: 14459
Re: To evaluate performance of used 18650 cells...
I noticed that the Opus tester is used by many professionals. If you use a constant current source, that still leaves the problem of monitoring the time it takes to finish the test at the voltage level selected to stop testing. I believe it's 1v for single cells and 3v for the 18650s. The one I use...
- Tue Jun 19, 2018 3:56 pm
- Forum: General Discussion
- Topic: Experimenting with Hot Glue..
- Replies: 103
- Views: 71943
Re: Experimenting with Hot Glue..
Hey MrAl, long time no see! I think you've hit the nail on the head with that last phrase. Just a comment on one of the threads to say, "Hey, we're working on it." would go a long way to ease the member's minds. Hi, Hello again, and yes it would be good ot hear something. I also see that ...
- Mon Jun 18, 2018 10:03 am
- Forum: General Discussion
- Topic: Experimenting with Hot Glue..
- Replies: 103
- Views: 71943
Re: Experimenting with Hot Glue..
Hi, I've seen enough web sites like this one go through changes that always have a negative effect on certain things like pictures and text and math equations made with Latex. I can only think that the the people who make the web sites dont understand the importance of getting file formats and other...
- Sat Jun 16, 2018 7:50 am
- Forum: General Discussion
- Topic: To evaluate performance of used 18650 cells...
- Replies: 22
- Views: 14459
Re: To evaluate performance of used 18650 cells...
Hello, The main check is the capacity. The capacity goes down as the cell ages so that's an indicator of how much the cell was used. To check the capacity, the simplest way is to use a constant current sink that draws current from the battery until it gets down to the lower cutoff voltage which is u...
- Wed Apr 04, 2018 9:33 am
- Forum: General Discussion
- Topic: heat sink cooling
- Replies: 5
- Views: 5712
Re: heat sink cooling
I want to install a muffin fan on the heat sink of a stereo receiver, my question is in what direction should the air flow? Blowing in the heat sink or sucking heat off the fins? Thanks Moe Hi, In most cases it is better to have the fan blowing on the heat sink, as close as possible to the heat sin...
- Mon Mar 12, 2018 2:29 pm
- Forum: General Discussion
- Topic: Soldering tarnished terminals!
- Replies: 2
- Views: 6313
Re: Soldering tarnished terminals!
Hi Len, I've used rosin flux in the past. I think it was G and C made for soldering, came in a small bottle. It comes with a brush, wipe it on, then solder. I've tried it as a test to solder an old penny and it worked pretty well, much better than with just the rosin core solder. Also, there are oth...
- Sun Feb 25, 2018 1:36 am
- Forum: General Discussion
- Topic: Detecting a magnet... from a distance.
- Replies: 23
- Views: 22315
Re: Detecting a magnet... from a distance.
Hello, I like the replies so far, very interesting. The 'rube' one was funny too thanks to Len for that one. Detecting a magnet from a distance isnt that easy because it's a static field so you cant use radio methods like tuned circuits to detect some frequency. Here are a few lesser ideas though ju...
- Sat Feb 03, 2018 10:03 pm
- Forum: General Discussion
- Topic: Very unusual desoldering method...
- Replies: 9
- Views: 6676
Re: Very unusual desoldering method...
Hi,
I get Godzilla to breath on the bottom of my boards and all the parts fly right off
It's not what you know it's who you know.
Or in this case, it's not what you know it's WHAT you know
I get Godzilla to breath on the bottom of my boards and all the parts fly right off
It's not what you know it's who you know.
Or in this case, it's not what you know it's WHAT you know
- Sun Jan 28, 2018 6:47 am
- Forum: General Discussion
- Topic: Adult Content!
- Replies: 6
- Views: 8740
Re: Adult Content!
Hi,
That's pretty funny.
I knew there had to be a good reason why we all got involved with electronics at one time or another. It's sexy
That's pretty funny.
I knew there had to be a good reason why we all got involved with electronics at one time or another. It's sexy
- Sun Dec 31, 2017 4:42 pm
- Forum: General Discussion
- Topic: really old 4700uF capacitors
- Replies: 9
- Views: 6113
Re: really old 4700uF capacitors
I found a case of common electrolytic capacitors that I left unused for 30 years. Seems to still work. I found one that heats up. But the rest seem to still work. I'm reading about how capacitors have a shelf life of 3 years. How can this be? https://www.google.com/search?source=hp&ei=3yFJWqroN...
- Tue Dec 26, 2017 3:06 am
- Forum: General Discussion
- Topic: Greetings!
- Replies: 31
- Views: 305885
Re: Greetings!
Hello there,
Merry Christmas and Happy New Year to you too, and all members of this forum.
Let's hope this year is a good one. For me it is a year of reorganizing my electronic parts and i've started already. So far invested over 150 bucks (USD) in storage containers of different types.
Merry Christmas and Happy New Year to you too, and all members of this forum.
Let's hope this year is a good one. For me it is a year of reorganizing my electronic parts and i've started already. So far invested over 150 bucks (USD) in storage containers of different types.
- Tue Nov 21, 2017 6:40 am
- Forum: General Discussion
- Topic: Another simple amp question
- Replies: 16
- Views: 8819
Re: Another simple amp question
Hello there, Any circuit you build for this that is linear will always waste a substantial part of the input power and thus will drain the battery quicker. Since it is all about current mostly with battery operated stuff, you could study the current drain itself and see if you can improve something ...
- Fri Nov 17, 2017 2:40 pm
- Forum: General Discussion
- Topic: Iron wire inductor
- Replies: 12
- Views: 8308
Re: Iron wire inductor
Hi,Lenp wrote:Never allow the facts to stand in the way of a good theory!
If the facts and the theory conflict, dispose of the facts.
Yeah sounds like a good rule (he he)
- Thu Nov 16, 2017 6:55 am
- Forum: General Discussion
- Topic: Iron wire inductor
- Replies: 12
- Views: 8308
Re: Iron wire inductor
Well, I was basing the post on my repair experience for older ovens. The transformer supplied both the filament and the high voltage, so to lower the filament voltage was a major redesign because the two windings were interconnected. I am sure, with an inverter design, the voltages could be adjuste...
- Wed Nov 15, 2017 7:33 am
- Forum: General Discussion
- Topic: Iron wire inductor
- Replies: 12
- Views: 8308
Re: Iron wire inductor
A note about microwave ovens...and stuff! The magnetron is an all on, or all off device. The power is cycled to it with a varying duty cycle to control the cooking power. If the supply voltage were reduced, the magenetron would probably function outside it's design limits and it may fail, or simply...