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  1. chopnhack

    Any Success With UV Cured Solder Mask Paint?

    Has anyone else used this stuff? I have tried twice now and have not been able to get it right... The first go, I tried with about 7-8 minutes exposure and the paint did not harden up. This time I gave it 10 minutes and the edges were a little wet still, so I went for another 4 minutes and I...
  2. chopnhack

    Question on KVL

    The video author mentions that when there is a current source in a loop, that loop automatically takes on that value. Is that true? I noticed that there was a voltage source in the loop and was somewhat confused since volt across a resistor would contribute to current! He says this at 1:07:15.
  3. chopnhack

    Question about carryover on 4017

    Hello all, playing around with the 4017 for some fun and simple 'board' time :) While toying with the decade counter, I discovered that the carryover bit triggers on the fifth output and stays lit through the ninth. Sure enough the datasheet confirms the carryout bit goes high as above and low...
  4. chopnhack

    Current up to a node?

    I understood all of them except question g. - Shouldn't the current at node I and H be the same since the current hasn't passed through the node yet? I.E. the voltage drop across the resistor is what determines how much current is distributed across this parallel network. Shouldn't the current...
  5. chopnhack

    Questions on LT3080

    Hi all, doing a little research on LDO linear regulators and came across a five pin package that I was not familiar with. http://cds.linear.com/docs/en/datasheet/3080fc.pdf In the schematic above they show Vcontrol being tied to the IN pin. In the pinout diagram they show Vcontrol as a...
  6. chopnhack

    Zeroing out a LM317 reference voltage with a zener - PSU build

    Hi all - continuing on the bench psu build, I have started to play with the design in spice to get an idea of how things are working and what purpose they serve in the schematic. According to the nuts and volts author whose plan I am loosely following, using a zener of 1.225v from the adjustment...
  7. chopnhack

    RthetaJC - top, bottom??

    I noticed that the datasheet of an LDO give the RthetaJC of the top at 16.1 deg C/W and then gives the bottom in two parts, one for the control section and one for the output section being 1.5 and 4 deg C/W respectively. When calculating for power dissipation and determining heatsinks, are we...
  8. chopnhack

    Scavenging MOT's for bench power supply use?

    I was contemplating re-purposing some microwave oven transformers that I have on hand. They are beastly things, but in my research I have discovered that they can not be used for extensive time periods because they operate in saturation? Can someone explain this to me? My intent is to rewind...
  9. chopnhack

    Op-Amp selection for inverting source signal - Bench PSU build

    Hello all, I am looking for some assistance in choosing an op-amp to invert an incoming signal. Specifically, I am trying to use a panel meter to read negative voltage. I hooked up the panel meter to a supply and then tried to use the meter to read the value of a battery in reverse and it was...
  10. chopnhack

    Bose Car Amplifier Repair?

    I had an issue with my car radio not playing any music whether CD or FM/AM was selected. I was able to narrow it down to the stock amplifier not working. (I disconnected amp and attached a tiny speaker to the pre-amp feeds and was able to hear music from each channel). I replaced the defective...
  11. chopnhack

    Converting Switch/Case statement in C to ASM?

    Hi guys, I have already done some research on this task, which I thought was going to be simple, but its not(at least for not for me)! I am trying to convert a switch/case statement in C from my previous program (see below): /* * PIC10LF320 * * 02/2016 */ #include <xc.h> #include...
  12. chopnhack

    Question about passing a variable value to an array in C

    Hello all, as the title states, I am trying to pass a variable into an array in C. Specifically I am trying to get the random value of TMR0 of the pic that I am working on into the array. The TMR0 status is an unsigned number from 0-255(I believe). I don't find much information on Google on...
  13. chopnhack

    Free TI Webinar SMPS Design

    http://links.mkt102.com/servlet/MailView?ms=NTA2MjE2NjAS1&r=MTM2NjczMTM0OTg0S0&j=ODYwNDUwMDEwS0&mt=2&rj=ODYwNDUwMDA4S0&rt=0
  14. chopnhack

    Don't Bin that Microwave!

    I never would have thought it, but microwave ovens have a lot of recoverable parts!! If you are asking why I say this, I took apart two that were destined for the land fill and was able to walk away with a small milk crate full of cool parts. Lots of relays, contact switches, t-stats (more...
  15. chopnhack

    Basic Physics Question

    While learning about current, the text states that charge/current is not consumed. KCL shows this as does the law of conservation of energy. What I don't understand intuitively is how charge/current is not consumed if they produce work? In more concrete examples we see energy given off with...
  16. chopnhack

    Wow...he calls it the Scariac!!

    I enjoy his videos, but man some of the things he shows.... I can imagine quite a few people injuring themselves!
  17. chopnhack

    Assistance with MPLAB C Code

    I am not sure of what I am doing wrong. I tried to access one LED on port RA2 of a PIC10LF320. I was able to get it to flash in ASM, but I am trying to work this out in C. So far I have successfully (I think) created my header file. My program compiles and loads, but no light from the LED. Any...
  18. chopnhack

    Help with C code or windows 7 cmd prompt pop up box

    Hi folks, reading a book on C programming, a modern approach and working through the examples. So far so good, best book on C I have ever read! One problem I am having with some of my programs is that they behave differently outside of the IDE. I am using codeblocks, but when I save my program...
  19. chopnhack

    Relationship of frequency and capacitance.

    Hello all, I am reading Electronics for Dummies.... yes, I am that desperate LOL I am 71 pages in and finally have found something to say, hey, I have a question: In the discussion of capacitors, it states how capacitors can be used to adjust the frequency of a signal. My thought was that the...
  20. chopnhack

    Help with debounce code

    Hello all, just dabbling with a bit of debounce code. Following along in the book "PIC MCU Programming" by Bert van Dam. I would highly recommend it for anyone who is feeling challenged by the disconnect between programming and the hardware interface of PIC's - this book seemed to break it down...
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