Search found 2662 matches

by haklesup
Thu Jun 21, 2018 11:19 am
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 440

Re: To evaluate performance of used 18650 cells...

If you can find a clock that you can start and stop with a control line, then it would not be too hard to make a 0.9V level detector with an op amp and stop the clock when the threshold is reached. Some MultiMeters had DataAcquisition ports and software, you can use like a datalogger. this was the c...
by haklesup
Mon Jun 18, 2018 2:30 pm
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 440

Re: To evaluate performance of used 18650 cells...

I noticed that Max discharge current is the other primary specification used for selection. Naturally you would want a high discharge current for say a super flashlight but lower discharge and a little more capacity for something like a low power toy. How do you suppose one would measure that spec. ...
by haklesup
Mon Jun 18, 2018 12:15 pm
Forum: General Discussion
Topic: What to do with Heathkit stuff?
Replies: 1
Views: 57

Re: What to do with Heathkit stuff?

Unless you are an Analog purest I think the Tubes should be ignored though it does give insight into how bipolar transistors work. As for the heathkit stuff, they are probably quite old and built with average quality components from the 60 to the 80s so they are probably going to have poor tolerance...
by haklesup
Fri Jun 08, 2018 10:14 am
Forum: General Discussion
Topic: Dell laptop battery question
Replies: 11
Views: 302

Re: Dell laptop battery question

by way of example, here is an article comparing 2 18650 batteries from the same manufacturer. Initially you can see one has higher max discharge current and the other has a little more capacity but in the discharge tests, they are very similar. Differences between brands I expect would be greater. I...
by haklesup
Tue Jun 05, 2018 4:15 pm
Forum: General Discussion
Topic: Dell laptop battery question
Replies: 11
Views: 302

Re: Dell laptop battery question

not all 18650 are equal, you could just have some with heavier walled cases and better discharge specs and other minor construction differences.
by haklesup
Mon Jun 04, 2018 4:24 pm
Forum: General Discussion
Topic: I need some wireless help and or advice.. lemme preach on...
Replies: 2
Views: 138

Re: I need some wireless help and or advice.. lemme preach o

what speed, 2400 only or also 5Ghz? This one looks easy to install and configure there is also an N300 version that's a little cheaper https://www.amazon.com/Thinkmart-Wireless-Repeater-Directional-Antennas/dp/B071RDTYMN/ref=sr_1_10?ie=UTF8&qid=1528156591&sr=8-10&keywords=wifi+extender+outdoor Or ma...
by haklesup
Mon Jun 04, 2018 4:00 pm
Forum: General Discussion
Topic: Dell laptop battery question
Replies: 11
Views: 302

Re: Dell laptop battery question

is there a voltage spec on the laptop itself. In any case the lower voltage should mean less voltage dropped across the internal regulators and it should run cooler and more efficiently. The new battery may have a better buck/boost regulator allowing for a flatter discharge curve rather than a gradu...
by haklesup
Tue May 08, 2018 3:55 pm
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 440

Re: To evaluate performance of used 18650 cells...

Looks like a nice inexpensive process. Capacity is not the only measurable parameter but it is a good catch all. Can you list the steps to your procedure?
by haklesup
Tue May 08, 2018 1:34 pm
Forum: General Discussion
Topic: Typical 0.1 μF bypass capacitor value...
Replies: 4
Views: 205

Re: Typical 0.1 μF bypass capacitor value...

for most digital circuits the smaller ceramic caps go as close to each IC power pin as possible and shunt higher frequency transients generated inside the IC from getting onto the power lines. Additional larger Electrolytic caps will go at the edge of the PCB where the power supply enters to shunt l...
by haklesup
Tue May 01, 2018 11:30 am
Forum: General Discussion
Topic: A Simple but Accurate Constant Current Source
Replies: 13
Views: 513

Re: A Simple but Accurate Constant Current Source

Have you checked the accuracy over a range of temperature? 1% is about as good as one could expect with resistors, its probably closer to 3% when you check it over a wide operating temp range but still very useful. Did you use precision resistors?
by haklesup
Tue Apr 24, 2018 12:42 pm
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 1880

Re: Detecting a magnet... from a distance.

your signal is diminishing as the cube of the distance while your detector is gaining in sensitivity linearly with the number or turns. I'm impressed you go to this distance but incrementally increasing the distance will quickly result in a coil so big you couldn't lift or afford it. additional loss...
by haklesup
Mon Apr 23, 2018 6:30 pm
Forum: General Discussion
Topic: Aftermaster
Replies: 5
Views: 295

Re: Aftermaster

if you are a consumer and want to be heard by a manufacturer, these days twitter and Facebook posts have a good chance of being seen. However if you want acknowledgement and recognition of a particular idea, that's not likely to happen, the research goes on in high quantity and a single voice will r...
by haklesup
Mon Apr 23, 2018 12:39 pm
Forum: General Discussion
Topic: Aftermaster
Replies: 5
Views: 295

Re: Aftermaster

A lot of newer TVs especially higher end already have the auto volume leveling but dialog enhancing seems like a hearing aid trick and could be useful to those without flat hearing response which is just about every adult. seems a little expensive but not too much so if you need it. These features c...
by haklesup
Wed Apr 11, 2018 9:18 am
Forum: Computer Programming
Topic: old windows 2K question something weird issue
Replies: 15
Views: 1823

Re: old windows 2K question something weird issue

"What angers me, is how certain software companies{MicroSquish} are getting so controlling over there programing languages. Example: If you use C++, and write a program with it. {MicroSquish} has the right to confiscate that program as there own, and you get none of the money you could of earned fro...
by haklesup
Tue Apr 03, 2018 12:33 pm
Forum: General Discussion
Topic: heat sink cooling
Replies: 5
Views: 379

Re: heat sink cooling

in isolation it doesn't much matter but pulling air out of the HS will tend to deposit more dust in the fins resulting in efficiency loss sooner. when blowing into the HS, the higher velocity will settle less dust. The shape of the cooler may also direct your thinking. If there is an airflow pattern...