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  1. hevans1944

    Why no more than 4 batteries in any particular string?

    Sounds like you have enjoyed a very interesting life. It's not looking very good in Des Moines IA if you can believe Fox News Channel. Oh, wait! I bet you don't even watch television. But how is it you have an Internet connection? Did you go with Startlink? I am thinking about getting a Starlink...
  2. hevans1944

    Why no more than 4 batteries in any particular string?

    Wow! Sixteen bux property tax on two acres. However, now that you have "improved" the property by placing a house on it, the local guv'mint will probably try to tax it out from under you. Better hide those solar panels, too, lest someone figure out a way to tax sunlight. I have visited Arizona...
  3. hevans1944

    Why no more than 4 batteries in any particular string?

    Ah! Affordable land. What a concept! Too bad that government can take it all away from you for any of several numerous reasons. Those reasons include eminent domain where the government offers you a "fair price" (an offer you cannot refuse) for your land; tax forfeiture where the government says...
  4. hevans1944

    Why no more than 4 batteries in any particular string?

    The storage of energy for later use was solved billyuns and billyuns of years ago here on Earth. The Sun provides the energy; life provides the storage. Ancient lifeforms lived and died under the Sun's rays, eventually leaving behind the seams of coal and the deposits of oil and natural gas...
  5. hevans1944

    Why no more than 4 batteries in any particular string?

    It takes a bit of experience to formulate AI inquiries in a manner that produces good results. And if you do use AI, treat like you would a brand new calculator you found under the tree... in 1960. I remember my very first Texas Instruments Four-Banger, a desktop job that ran off of shore power...
  6. hevans1944

    Introduction

    Welcome to the "new and improved" forum! What is your background (experience in electronics)?
  7. hevans1944

    Why no more than 4 batteries in any particular string?

    I got the following answer from Grok 4 on X.com: The warning in LiFePO4 battery manuals against connecting more than 4 batteries in series or parallel is a common guideline from manufacturers to ensure safety, longevity, and optimal performance, particularly in consumer-grade setups like solar...
  8. hevans1944

    What kind of switch is this?

    Why do you need to order a dozen of something you know nothing about? Why do you think your example came from a toy? Are you trying to make or repair a toy (or toys) that require a dozen of these switches? Can you determine whether the device you have is a normally-open switch that closes when...
  9. hevans1944

    Hi there!

    From one "old timer" to another, I think you will fit in just fine here. Your contributions might even encourage others to return to this forum now that it has morphed from MakerPro (whatever that means) to Electronics-lab (and we know what that means). It sounds like you earned a lot of your...
  10. hevans1944

    Strange old capacitor

    I wondered about this too, especially when I was tasked with deciphering foreign schematics. IMHO, there should be two, and only two, schematic symbol representations for a capacitor: one symbol for a fixed capacitance and an identical symbol with an arrow through it for a variable capacitance...
  11. hevans1944

    OLD Tektronix Oscilloscope Identification

    A friend here (@chopnhack) and I collaborated a few years ago (it was Electronics Point back then) on a project involving him measuring alternating current on operating woodworking equipment. This was to enable a workshop dust collection system that serviced several woodworking power tools. The...
  12. hevans1944

    Signal generator to drive Ultrasonic transducer

    @poor mystic: yeah, your description is a demonstration of "you can't get something for nothing" or TANSTAAFL (There Ain't No Such Thing As A Free Lunch). Mechanical impedance-matching between ultrasonic transducer and whatever load it drives is important, too, but I don't know how to do that...
  13. hevans1944

    OLD Tektronix Oscilloscope Identification

    I use a Hantek DSO5202P. This is a 200 MHz bandwidth, dual-channel, digital storage oscilloscope with 40K of display memory. It samples inputs at a one gigahertz rate. Go to the link for pictures and more specs.
  14. hevans1944

    Not Understanding Arduino useage versus traditional Electronics useage in Devices.

    Thank you for your reply to my comments. As you said, "To each his own." I am curious why you stated that in 21 years you will be 100 years old. Is that your life expectancy? That would probably mean that you are now approximately 79 years old, a relative youngster for those fortunate enough to...
  15. hevans1944

    Strange old capacitor

    Almost all wire-wound resistors are slightly inductive. This is more of a concern at radio frequencies than at audio frequencies. The typical wire-wound resistor is a power resistor and is used in circuits where it must dissipate a significant amount of power in a smallish amount of space. Most...
  16. hevans1944

    Signal generator to drive Ultrasonic transducer

    The OPA541 power op-amp requires both a positive and a negative power supply, both referenced to the same common, to produce a bipolar output. It can also operate with a single power supply, up to 80 VDC, but the output will be a single polarity with respect to common. If the op-amp is...
  17. hevans1944

    Strange old capacitor

    I don't have much of a problem replacing passive components, such as resistors, capacitors, and inductors with their modern equivalents. Hiding modern components in the "shell" of older components is okay by me, too. But some of the "restored" stuff simply retains the original cabinet and...
  18. hevans1944

    OLD Tektronix Oscilloscope Identification

    @John R Retired, your "small 200 KHz scope" sounds a lot like the EICO 460K oscilloscope that I built with newspaper route money when I was a teenager. I learned a lot using that instrument, but it wasn't until I joined the Air Force that I realized how primitive its sweep circuit was: a...
  19. hevans1944

    Not Understanding Arduino useage versus traditional Electronics useage in Devices.

    John, you will have to linger here for awhile to understand @Delta Prime. I think of him as a mature idiot savant but he is probably much more than that. Definitely a very intelligent person, but sometimes rather snarky. I suspect, like me perhaps, that he has little tolerance for the...
  20. hevans1944

    motor advice

    The length of the chain affects the weight (mass) that must be moved initially. Each time the chain is stopped, for whatever reason, this mass must be accelerated again. Torque is the rotational equivalent of Newton's Laws describing linear motion. The most famous is this one: F = M x A, where...
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