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  1. Fish4Fun

    Newbie Help - 1 switch, 2 circuits with Optocoupler

    Hey Richard! By "Active High" // "Active Low" I mean that the "on" state is signaled by Vcc or Ground. In Common Parlance a switch "powers on" a device seeming to suggest that the switch is controlling "Hot" // Vcc // V+ . This idea is reinforced by everyday experience with things like light...
  2. Fish4Fun

    Newbie Help - 1 switch, 2 circuits with Optocoupler

    Hey Richard! I was hoping your schematic would be a little more than it is .... but perhaps it is enough to start.... I am **assuming** the "red traces" are +3.3V ? I ask because (as counter intuitive as it might seem) typical, simple, low voltage switches.... switch ground and not Vcc...
  3. Fish4Fun

    Newbie Help - 1 switch, 2 circuits with Optocoupler

    Hey Richard, Welcome to EP! While I am a bit confused about what the "old camcorder's" role is in all of this, if it is "working perfectly" then I don't need to. I suspect the "problem" is as much ergonomics as electronics; however, if you have a schematic by all means post a link to it...
  4. Fish4Fun

    Resistors, Capacitors, Zener diodes... Why the funny values?

    (*Steve*), Thanks! I always **assumed** the reason for the "odd values" involved +/- xx%, but it was fascinating to read the math behind how the particular values were selected. Again, Thanks! I know the current trend in electronics is toward SoC ICs and further and further away from...
  5. Fish4Fun

    Distant Relay Module Circuit Help

    Hey Farukh! Google is your friend .... http://howtomechatronics.com/tutorials/arduino/control-high-voltage-devices-arduino-relay-tutorial/ Good Luck! Fish
  6. Fish4Fun

    Distant Relay Module Circuit Help

    Hey Farukh! As kellys_eye stated, you are much better off buying ready-made relay modules ... here is an ebay example: https://www.ebay.com/itm/NEW-5V-1-2-4-8-Channel-Relay-Board-Module-Optocoupler-LED-fr-Arduino-PiC-ARM-AVR/222745770387?hash=item33dcaeb993:m:mma_l6pmGcnIAvIWlRTSkjQ ...Just...
  7. Fish4Fun

    Zero Crossing Point Detector .....

    Hey Minder! I am more confused than ever ... The ***Hall Effect Commutation Devices*** are what separate a conventional BLDC motor/driver from a "Sensorless" BLDC motor/driver .... The "Sensorless" BLDC driver determines commutation timing by sensing the voltage on the floating phase (Back...
  8. Fish4Fun

    Zero Crossing Point Detector .....

    Hey Minder! Perhaps I am confused ... happens sometimes :-) All of the industrial servos I have dealt with (really, not that many) use some type of encoder, and pretty much require servo drivers.... Variable Speed BLDC Spindle motors I have dealt with have not had encoders, but rather have...
  9. Fish4Fun

    Solar powered fan

    Hey Dustin! You are **WAY** over-thinking this :-) Firstly direct sunlight has ~1kW per square meter in energy readily transformed to low grade heat. Calculating heat gain, temperature rise etc, etc requires all kinds of assumptions and still leads to some mind-numbing math, but is fairly...
  10. Fish4Fun

    Wanted: linear actuator 12/24V 6-7" extension 30-50lbs,fast 10mm/s

    Hey Josh! You may need to offer a few, more salient, details :-) Linear Actuators are readily available in a wide range of sizes, speeds, powers, resolutions, and OF COURSE prices, LoL. One that will push a pallet of bricks 25ft in 10 seconds with an accuracy of +/- 0.0005 inches is going to...
  11. Fish4Fun

    Zero Crossing Point Detector .....

    FYIW *** This is as much a thought experiment as it is a real-world problem .... *** Typical "Hobby" Oriented BLDC motors and even recent "Industrial" BLDC motors are designed and built to be driven using "sensorless" drivers .... Of course "sensorless" is a Red-Herring, the motors//drivers...
  12. Fish4Fun

    Agilent logic analyzer 16822a

    Hey mohddalim! Welcome to EP! Logic Analyzers are really handy for trouble shooting bus lines in systems where Parallel communications protocols are employed .... but the general trend for most systems (the last couple of decades) has been toward serial protocols .... with the obvious...
  13. Fish4Fun

    LA H component id

    Welcome to the EP Forum! Hrmmm is this a part removed from a PCB? or is it a "new surplus part"?? If it was removed from a PCB, knowing the PCB function and tracing the connections could help narrow the possibilities and perhaps even suggest a replacement ..... If it is a surplus "custom"...
  14. Fish4Fun

    Need help interpreting Mosfet turn-on delay / rise time

    Hey Royalmp2001! Everything Harlod said is absolutely correct.....but may not help you make your decision.... If you truly want some help selecting a mosfet, I would urge you to post details about your circuit and anticipated use, market, or production quantity. There are thousands of Mosfets...
  15. Fish4Fun

    Benchtop PWM Generator

    ;Found a Dyslexia Moment ...... Can't edit the above post ..... I removed the Direction settling time, and decreased the pulse width to 16 system clocks ... using the 8Mhz internal clock, this ***Should*** allow operation up to at least 200kHz ... Now I just need to make sure an ATMEGA2560...
  16. Fish4Fun

    Benchtop PWM Generator

    Progress Report...... I have drawn up a schematic to test the TL494's .... but I haven't had a chance to cut a PCB yet .... Maybe next week. I did "play" a bit with a Gray Code translator..... Looked at various solutions posted online ... considered a couple, but @ the end of the day I was...
  17. Fish4Fun

    Benchtop PWM Generator

    @adam.... Kinda what I was thinking ... Thanks! @Anyone.... At the risk of Hi-Jacking my own thread.....(But in my defense: Same Project, Same Lead-In .....) Is there an up/down Gray-Code Counter IC? Or an IC that translates a two-channel encoder input into "pulses" with a "Direction...
  18. Fish4Fun

    Benchtop PWM Generator

    @adam.... Thanks for the link! Interesting chip, I <think> that I would like to play with one....They are ~$10 from DigiKey (reasonable enough) .... ebay-China has the ICs listed for ~$4 each or several permutations of Demo Boards ranging from ~$6 to ~$40 ...any thoughts or suggestions? The...
  19. Fish4Fun

    Benchtop PWM Generator

    @Alec_t --> Not exactly what I was thinking, BUT absolutely perfect! and @ $0.58/ea delivered, I went ahead and ordered 20 to play with :-) I figured I couldn't be the first person to need a variable frequency/duty PWM IC. @$0.58ea they are certainly cheap enough to embed in any future...
  20. Fish4Fun

    Benchtop PWM Generator

    I have bins full of projects in various states of completion because some number of hours/days/weeks/months into the project I "discovered" there was a better solution ready-made for some relatively trivial price or some Open Source project easily modified to suit my needs..... Yesterday I...
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