Search found 2906 matches

by haklesup
Wed Jun 16, 2021 6:36 pm
Forum: General Discussion
Topic: How does a voltage divider circuit to run an LED?
Replies: 6
Views: 432

Re: How does a voltage divider circuit to run an LED?

its a perfectly reasonable way but does not provide as much safety factor as it would if you put a regulator in between. For example if the LED fails and goes open circuit, the full voltage will be across its terminals. 62VDC is safe but 62VAC might give a little zap if it were under 40V I would sug...
by haklesup
Thu May 27, 2021 1:08 pm
Forum: Computer Programming
Topic: Understand how to divide two 16 bits number in 8051 microcontroller?
Replies: 3
Views: 445

Re: Understand how to divide two 16 bits number in 8051 microcontroller?

unsigned 16 bit means all 16 bits contribute to the value, in signed, the MSB indicates negative or positive. your link seemed to lead to a datasheet page, I don't want to find the relevant section you are referring to but I suppose you are seeing a programatical (code) example of how to do binary m...
by haklesup
Thu May 27, 2021 12:42 pm
Forum: General Discussion
Topic: Streaming question
Replies: 7
Views: 214

Re: Streaming question

a 32GB or 64Gb memory card can hold more than 100 DCs of music easily. There may not be many services that allow people to upload and stream their music due to copyright laws. The liability to a service that you might use your streaming service as a free broadcast radio station is high and that may ...
by haklesup
Tue May 25, 2021 1:25 pm
Forum: General Discussion
Topic: APC UPS1400 help
Replies: 3
Views: 247

Re: APC UPS1400 help

the fan is probably controlled by a thermocouple. It may be open or inaccurate and not allowing the fan to turn on or the PWM fan controller is dead. If yu want to keep variable speed, an easier fix might to be to hotwire the fan with an off the shelf Fan controller intended to be installed in a PC....
by haklesup
Tue May 25, 2021 1:13 pm
Forum: General Discussion
Topic: DIY pancake slip ring
Replies: 2
Views: 145

Re: DIY pancake slip ring

Mill-max has some spring pins (pogo pin style) in plastic strips, the omniball is specifically designed for this application https://www.mill-max.com/products/new/omniballtm-spring-loaded-contact https://www.mill-max.com/products/new/omniballtm-spring-loaded-contact-options if you want stamped and f...
by haklesup
Thu May 13, 2021 10:51 am
Forum: Nuts & Volts Magazine Discussions
Topic: Are old magazines available in compact disc ?
Replies: 5
Views: 9565

Re: Are old magazines available in compact disc ?

Ask at your local library if they can locate them on microfilm. Its a long shot but that's the way it was done before the internet. Someone probably did but locating the films and the person who remembers they exist might be a trick.
by haklesup
Tue May 04, 2021 12:59 pm
Forum: General Discussion
Topic: Ground Loop Problem
Replies: 7
Views: 880

Re: Ground Loop Problem

you'll run in circles trying to rid electrical noise by modifying the "Safety Grounding" since the ground of concern is the "Signal Ground" comprised of the shield in the Coax cable. All that other stuff is only to protect you from electrical shock in the event of a fault or lightning and was never ...
by haklesup
Fri Apr 23, 2021 12:53 pm
Forum: General Discussion
Topic: Ground Loop Problem
Replies: 7
Views: 880

Re: Ground Loop Problem

for RCA connectors or 3.5mm jacks and low level signals, a "ground loop isolator" transformer works very well, this comes up a lot in Car audio connecting head units to amplifiers when relying on chassis for ground. lots on amazon or ebay etc. Just install it in series at either end, it does not nee...
by haklesup
Thu Apr 15, 2021 5:00 pm
Forum: General Discussion
Topic: Crappy Headphone wires.......
Replies: 11
Views: 3315

Re: Crappy Headphone wires.......

are there any markings on that wire? Much of that construction is for flexibility and shielding, probably any cable with the right number of conductors could be substituted with some mechanical compromise. USB C cables probably have a compatible combination of conductors and flexibility, some USB mi...
by haklesup
Thu Apr 15, 2021 3:35 pm
Forum: General Discussion
Topic: Compressor problem
Replies: 10
Views: 4113

Re: Compressor problem

my last test was on a solitary 20A outlet with a 3 foot run the main panel, no voltage drops there

My bet is damaged coil, shorted or open, who cares at this point. Darn, I just realized I forgot to put it on the curb Wednesday with the other metal junk, he can have it next time.
by haklesup
Tue Apr 06, 2021 1:40 pm
Forum: General Discussion
Topic: Compressor problem
Replies: 10
Views: 4113

Re: Compressor problem

I'm scrapping that compressor. It has oil in the pump, it never went dry but may have begun break down, I never replaced it. For some reason the motor stall torque has gone way down. I did change the cap but stopped short of replacing the pressure switch when I observed it could not pump more than 5...
by haklesup
Tue Apr 06, 2021 12:25 pm
Forum: General Discussion
Topic: Copper clad Al wire
Replies: 4
Views: 495

Re: Copper clad Al wire

I did get some 10 gauge I plan mostly to use with crimp connections but it seems that I should be able to solder this using lead free SAC solder alloy that contains some copper already to help prevent the thin copper cladding from dissolving in the solder. There may be other solder alloys that can w...
by haklesup
Wed Mar 31, 2021 12:31 pm
Forum: General Discussion
Topic: Copper clad Al wire
Replies: 4
Views: 495

Copper clad Al wire

Has anyone used the copper clad aluminum hookup wire now common on Amazon (stranded hookup wire various gauges and colors). It cost half the price of 100% copper and especially for heavy gauge the savings is tempting but I think I have always used all copper wire or tinned copper. The application is...
by haklesup
Thu Mar 18, 2021 4:48 pm
Forum: General Discussion
Topic: Adafruit 1.2" led display
Replies: 11
Views: 1101

Re: Adafruit 1.2" led display

did you see the link on that page where it says they have plenty

https://www.adafruit.com/?q=1.2%22+7-se ... =BestMatch

appears they have 2 shades of green, am I missing something?
by haklesup
Thu Mar 11, 2021 10:41 am
Forum: Computer Programming
Topic: need tips on building a large screen calendar.
Replies: 4
Views: 4924

Re: need tips on building a large screen calendar.

IMO it would be cheaper and easier to operate if you just got a regular smart TV and cast the calendar to it from a tablet or phone. R-Pi is OK if you are familiar but there are plenty of small embedded PCs running Andriod, Windows or Linux that would be easier to configure if the TV itself didn't h...