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  1. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Depends on how big (diameter) the cables are, how much charging current and discharging current flows during the AC line cycle, how much voltage drop as a consequence thereof you can tolerate, how important the minor added inductance of the connecting cables are... yada, yada, yada. For the...
  2. hevans1944

    Yenka and PCB Creation

    Have you considered sending an e-mail describing your problem to [email protected]?
  3. hevans1944

    Connecting car battery to a portable speaker.

    CCA = Cold Cranking Amperes, maximum amount of current the battery can supply when providing power at some minimal rated temperature. Useful specification for sizing battery to engine starter-motor current requirements. Means absolutely nothing for your application. As previously stated...
  4. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    As well they should have! Here is a link to the original application note, which must have been created shortly after TI absorbed Burr-Brown on June 21, 2000. I had not seen this TI application note until I went looking for it as a result of @Audoguru's response to my query. While reading the...
  5. hevans1944

    Please help with alarm panel

    Here is a link to the PDF Installer's Manual. After the file downloads and is saved in a folder on your computer, open it with Adobe Acrobat Reader. Pretty heavy reading, probably instantly understandable to installation techs, but not so much by the end-user.
  6. hevans1944

    Help selecting my 1st DSO please.

    I would also get one of the el-cheapo battery-operated DSO kits too. There are times when you will want the electrical isolation from the real world that only a battery can provide. That is the main reason I purchased a Mooshimeter last year... well,that, and the overall coolness factor. Works...
  7. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    I like @AnalogKid's explanation. It also agrees well with the TI graphs that include noise on the input signal. Of course, with just a wee little bit of positive feedback, enough hysteresis can be introduced to overcome noisy inputs. So I am a big fan of deliberate and controlled hysteresis with...
  8. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    The Texas Instruments application note is "spot on" in accuracy and detail. All you ever wanted to know about comparator hysteresis in one article. TI is my "go to" source for technical information. I have been using their products since the 1960s, first for logic and later (after their purchase...
  9. hevans1944

    Help selecting my 1st DSO please.

    Excellent choice IMHO! There is a 200 MHz bandwidth version available (5202B) that you should buy if you can afford it. I purchased the DSO 5202P last year and am very pleased with it. The Hantek 5000 series is a very nice DSO that has been extensively hacked to provide increased bandwidth...
  10. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Not irritated at all, as you seem interested in actually learning about electronics, instead of just blindly copying what other people have done. Learning about feedback was a hugely complicated effort for me in the 1960s because I didn't yet have either the math background or an understanding...
  11. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Did you not understand @Audioguru's comment that comparators always require hysteresis to avoid oscillation near the switching point? The circuit you posted uses a CA3140 op-amp as a comparator, but it DOES NOT provide any positive feedback that is necessary to implement hysteresis. Do you think...
  12. hevans1944

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Here is a link to the original Electronics Lab project page, which also contains a link to the website of the Greek Smart Kits, but no indication that the kit is currently available there. Please read all the comments regarding other people's attempts to build this project with varying degrees...
  13. hevans1944

    Power-One power supply mod

    Yeah, I tend to ignore the losses in the bridge rectifier and the series pass transistors, folding them into about a +20% "fudge factor" increase in transformer VA rating above that actually required by the load. So, by that criteria, I would pick a VA rating of at least 90 + 18 = 108 VA. If you...
  14. hevans1944

    Huntron Tracker 2000

    Exactly right. Whatever gets the job done at an affordable cost is the method to use. It is just my personal opinion that this "test instrument" is waaay overpriced for what it does. Your mileage (or kilometers) may differ.
  15. hevans1944

    Power-One power supply mod

    The markings on the transformer indicate this is not the case. The total power is 120 VA shared by the two secondary windings. At 28 VAC for each winding, that works out to about 120 / 28 = 4.286 A shared across two windings, or about 2.15 A per winding. That's a pretty far cry from the 3 A per...
  16. hevans1944

    Huntron Tracker 2000

    For an instrument that is seventeen years old, yet shows little indication of use or wear, that should be a red flag concerning its utility for electronics troubleshooting. This is nothing more than a crude "curve tracer" with self-excited "test" probes providing pseudo-constant-current...
  17. hevans1944

    Hi

    Welcome to EP @Rip01! Ummm, "just an amateur" means what? Amateur radio operator? Amateur electronics experimenter/builder? You have found exactly the right place for amateurs of every color and stripe, especially newby amateurs. Read some of the historical posts in the various forums to get an...
  18. hevans1944

    Wiring mental block

    Sensing which button is pressed is probably simple... one wire for each button, eh? But then the circuit, it would also have to somehow keep track of how many "button pushes" have already been issued, so it "knows" where in the sequence you already are, and can therefore issue the appropriate...
  19. hevans1944

    Generator Problems and Connection

    You seem to be casually ignorant of the perils of backfeeding your generator output into the mains supply. The mains supply is derived from a step-down distribution transformer whose primary is 7kV or more. Backfeeding this transformer with your generator set will energize the primary at its...
  20. hevans1944

    What would be the best soldering iron for $200 and under?

    The tips are somewhat pricey... about five bux plus shipping from DigiKey... but they last a long time if proper care of them is taken. What most people balk at is the price of the heating element and its handle and the price of the base unit containing the low-voltage transformer. New, these...
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