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  1. Fish4Fun

    Effective use of DC

    Matt, Go here: http://www.gotwind.org/ the site owner's name is Ben, great guy who has done what you are doing. I don't know how much help he will be on the technical side, he solves technical problems the old fashion way, he hires people. I will continue to insist you would be far better...
  2. Fish4Fun

    I would like some help identifying what parts to purchase for project.

    Produce electricity? Really? I love Tesla as much as anyone; however, despite his genius, he had some real hair-brained ideas. Three Phase Alternating Current, Brilliant! Death-Ray, not so much. What you have to understand is his lack of comprehension about the physics of radio frequency...
  3. Fish4Fun

    Effective use of DC

    Matt, First, USB Supply Currents are specified as: Second, DC to DC converters are typically designed for ~80% efficiency because this is the min/max between design cost and production cost applied to usage cost. DC to DC converters are available up to 95% efficient, at a significantly...
  4. Fish4Fun

    Effective use of DC

    Prolly best to back up a bit and explain the actual situation a bit better, but I think I got it. When you say "High Current 5V feed", exactly how high a current are you looking for? 72V * 40A = 2.88kW. 2.88kW/5V = 576A; however, the conversion efficiency at this current is likely to be...
  5. Fish4Fun

    want to know a value of transistor

    http://www.ebay.com/itm/New-1-Channel-H-L-Level-Triger-Optocoupler-Relay-Module-for-Arduino-12V-/350877285342?pt=LH_DefaultDomain_0&hash=item51b1ea7bde Make this easy on yourself. Fish
  6. Fish4Fun

    ArchitecturalModel Dilemma..

    @==> Laplace hehe, you didn't label the center limit switch for him, how will he get his A? To be honest I have stared @ the schematic for ~10min and my ADD/ADHD has gone into overdrive (I want to put it together to make sure), but I believe your schematic meets all of the assignment...
  7. Fish4Fun

    How do you think about this tseting?

    I guess a lot depends on how much it is, lol. @ $10 it looks fabulous, I'd order two! @ $1k you would need a lot more than a screen shot, and even if I needed one badly I would have to think long and hard about it. This is only one of several posts about this device...
  8. Fish4Fun

    2 Stepper motors in sync

    ASS-U-ME ing you use the same input to two stepper drivers, AND the drivers and the steppers are powerful enough you should be able to maintain fairly level open loop synchronization. BUT, WHY? I would use a single motor and either belt or chain drive; OR rails and a single lead screw. Heck...
  9. Fish4Fun

    The Ultimate Transistor Amplifier

    rogerk8, I have left this alone for several days thinking someone else might point out that your schematic is a simplified drawing of a standard 1/2 H Bridge, traditionally used in audio amplifiers in the linear region configured as Class AB amplifiers. The problem with this type of amplifier...
  10. Fish4Fun

    12 V power supply.... Is this normal?

    hehe, and if you measure the DC output voltage following a bridge rectifier with a capacitor across it you will measure 17 * 2^1/2 = ~24V (depending on the rectifier voltage drop and capacitor leakage current) across the center tap and either leg, or 34V * 2^1/2 = 48V (same note). The reason...
  11. Fish4Fun

    Variable power supply

    Yes, Read this first: https://www.electronicspoint.com/hot-wire-cutter-power-supply-t263064.html Next, a charger might not be the best choice for a hot wire cutter. Next, 2.5A is likely not enough current for a hot wire cutter. A potentiometer will NOT work well for your purpose. Fish
  12. Fish4Fun

    Piezo injection and high side FET drivers

    Ok, I was unfamiliar with the high voltage of piezo injectors. Assuming Diagram1 (semi-resonant) this brings up the value of L1. I assume this is being used as a boost-buck converter ramping your voltage up to 120V-200V using driver1 & driver3? Or are you using the resonant configuration in...
  13. Fish4Fun

    Current monitoring relay?

    A simple voltage comparator and a small series resistor (~ 0.1Ohm )would do the job if a particular current through the bulb were the goal. If a particular light output were the goal you might consider a small Solar Panel (perhaps one salvaged from one of those solar powered yard lights...
  14. Fish4Fun

    Hot Wire Cutter Power Supply

    Honestly you shouldn't need a circuit breaker on the primary side, and you really shouldn't need one on the secondary side either unless you are trying to protect your nichrome wire. A proper transformer will withstand a direct short across its secondary for a fair length of time. The primary...
  15. Fish4Fun

    Piezo injection and high side FET drivers

    If I had to guess, I would suspect that the switching frequency is too low. Assuming an 8 cylinder 2-stroke diesel @ 3600 RPM any given injector would fire @: 3600 RPM / 60 Seconds = 60 times per second, or 60hz. 1/60 = 16.6mS In the world of high-side FET drivers this is an...
  16. Fish4Fun

    Wiring dimmer switch into a circuit

    Hrmmm, Several things. First, you have written: P = IV V=P/I 120=V/I = 3 I have no idea what you are doing here, the two formulas in question are: E=IR P=IE Where: E = Voltage I = Current R = Resistance P = Power Assuming E = 120Vac @ 60hz and a 40W bulb this should lead...
  17. Fish4Fun

    Circuit for a keyless ignition switch.

    Hrmmm, Your ignition switch serves three purposes: 1) Disable the motor 2) Enable the motor 3) energize the starter contactor. This is typically done with a three position switch with the third position being "momentary", and the second position being "enable the motor". This could easily be...
  18. Fish4Fun

    Circuit for a keyless ignition switch.

    The Safety side worries me. First note: Are you sure your starter pulls less than 30A? This seems low to me (360W is not much). Moreover, your starter should already have a contactor or relay, so your ignition switch should only be driving it, not the starter directly. Second note: Alarm...
  19. Fish4Fun

    ArchitecturalModel Dilemma..

    First thing to do is express in Boolean logic what your movements are. From there you can use either discrete logic or a microcontroller to control the movement. As this is a school project with an implied completion date, you should carefully consider your skills prior to committing to any...
  20. Fish4Fun

    basic electronics (or is it?) --> carnival project

    Gert, Lots of approaches to this, but all pretty much require a fair background in electronics/logic. While discreet logic ICs can certainly provide a solution, you should probably consider using a microcontroller. The Arduino family of prototyping boards are designed specifically for...
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