Search found 2669 matches

by haklesup
Tue Aug 14, 2018 11:32 am
Forum: General Discussion
Topic: i need a long QR type code identified
Replies: 10
Views: 44

Re: i need a long QR type code identified

Likely because it is proprietary and contains payment information (the value of the postage) they probably don't want anyone tampering or learning how to make free stamps. If that is the case, no public app will have access to the database the code points to.
by haklesup
Thu Aug 09, 2018 12:03 pm
Forum: General Discussion
Topic: Beheaded fatty nail as soldering tip...
Replies: 20
Views: 374

Re: Beheaded fatty nail as soldering tip...

(from wiki) Above1700 °C (1973 K /3583 °F) in vacuum or oxygen-free atmosphere, diamond converts to graphite; in air, transformation starts at ~700 °C. Diamond's ignition point is 720–800 °C in oxygen and 850–1000 °C in air I think of those folks rummaging through ash in the CA wildfires and finding...
by haklesup
Tue Aug 07, 2018 3:58 pm
Forum: General Discussion
Topic: Beheaded fatty nail as soldering tip...
Replies: 20
Views: 374

Re: Beheaded fatty nail as soldering tip...

"Reminds me of when cutting steel with a diamond impregnated circular saw blade. The diamond tends to dissolve" Probably due to overheating or advancing too fast. When using diamond to cut anything the key is slow and cool. While a diamond is very hard, they can be burned at a lower temp than the me...
by haklesup
Fri Aug 03, 2018 11:29 am
Forum: General Discussion
Topic: wireless door button - several failed.
Replies: 15
Views: 310

Re: wireless door button - several failed.

in almost all cases this is a bare die epoxied to the PCB then gold bond wires ultrasonically welded to the die and PCB pad then covered with a "Glob" of epoxy. Its pretty close to a packaged device technology but is even lower cost for high volume products. For more most chips, they almost always c...
by haklesup
Wed Aug 01, 2018 1:13 pm
Forum: General Discussion
Topic: wireless door button - several failed.
Replies: 15
Views: 310

Re: wireless door button - several failed.

I hear the complaints about buttons. For new projects with uControllers, there is lots of support for capacitive touch keypads, sliders and other button configurations on ebay and other places to get modules. No need to use mechanical buttons if you are determined. Unlikly any would eb compatible to...
by haklesup
Tue Jul 10, 2018 3:11 pm
Forum: General Discussion
Topic: Line Array - Anyone have experience?
Replies: 5
Views: 189

Re: Line Array - Anyone have experience?

Interesting but I don't get why. Does it have a special sound quality? I can see if you drove each one separately with some kind of DSP you could probably do some interesting stuff but if all driven from the same source, in phase I wonder how it's sound differs from a typical enclosure with similar ...
by haklesup
Tue Jun 26, 2018 10:45 am
Forum: General Discussion
Topic: Experimenting with Hot Glue..
Replies: 101
Views: 15257

Re: Experimenting with Hot Glue..

I wonder if the Silicone II would have worked better. In any case, there are spray on Silicone conformal coating products if you really needed that kind of protection. In most cases a urethane conformal coat is sufficient and is removable with acetone. Most modern parts can survive acetone but I wou...
by haklesup
Thu Jun 21, 2018 12:19 pm
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 2299

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 3:30 pm
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 2299

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 1:15 pm
Forum: General Discussion
Topic: What to do with Heathkit stuff?
Replies: 1
Views: 777

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 11:14 am
Forum: General Discussion
Topic: Dell laptop battery question
Replies: 11
Views: 1452

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 5:15 pm
Forum: General Discussion
Topic: Dell laptop battery question
Replies: 11
Views: 1452

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 5:24 pm
Forum: General Discussion
Topic: I need some wireless help and or advice.. lemme preach on...
Replies: 2
Views: 931

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 5:00 pm
Forum: General Discussion
Topic: Dell laptop battery question
Replies: 11
Views: 1452

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 4:55 pm
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 2299

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?