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  1. dorke

    HELP WITH UNDERSTAND OF NAND GATE CIRCUIT?

    Hop actually I did. For an alarm system which would be run from mains supply with battery-back up. the added power consumption is neglectable . A constantly on led will draw about 1.5mA in this circuit. Assuming the osc. in the original has a duty cycle of about 50% it will draw on average...
  2. dorke

    help with heat sink

    Yes K and C the same per W. Your device will be at 85+45=130 ,not good at all:(
  3. dorke

    help with heat sink

    85c ambient in a car? Is it in the engine compartment? Very demanding environment. Tj of 150C is device destruction ,you should be below 125C for opertation. look at page 25-26 in the data sheet , with a "good" heat sink To-220 reis above ambient for 5V/3A is about 35C putting the junction...
  4. dorke

    Need help with SSR Wiring

    What SSR are you using? What kind of motor? What is written above "7.2v"? What diode do you plan to use?
  5. dorke

    Trying to Understand Full-Duplex Intercom Circuit

    Welcome to EP. About the Capacitors: C6(DC blocking cap) : If the entire intercom system was contained in a single closed box, you could theoretically eliminate cap C6 since you wouldn't have any DC voltage on the "audio bus line",the presence of C5 (DC blocking cap )should be enough. But...
  6. dorke

    help with heat sink

    Your assumptions of what is the power in watts that will create heating is correct. But ,where did you get the 80% number? The number usually varies and depends on the actual working condition of the device. Another question you need to answer is: What is the allowable rise in temperature of...
  7. dorke

    Amp keeps going into protection mode

    Yes
  8. dorke

    Amp keeps going into protection mode

    O.K . On the Indicator board identify connector S1,it is a 7 pin one. You should cut the wire that goes to pin 5(DC sense),cut it at a distance so it will be easy for you to reconnect it later. I can't see the numbering of the pins on S1. We can identify them like that: pin 2 should show zero...
  9. dorke

    opamcircuit output

    No, You should study what is an op. amp , what are it's properties , how does it work and how is it used in circuits. You can start here for basics
  10. dorke

    Amp keeps going into protection mode

    Rick, All these measurement shouldn't trip the protect mode. A digital scope is what we should use but most likely don't have one. Do you have a cutter? Would you be able to reconnect a wire back(solder or other way?) if we disconnect one?
  11. dorke

    opamcircuit output

    You are approaching this the wrong way. Spice is letting you know what was already provided to you before ,8V. Does it help you understand why? No it doesn't . Here is another hint for you: From the question:"op-amps are ideal", Ideal op-amp has infinite voltage gain and infinite input resistance.
  12. dorke

    Amp keeps going into protection mode

    Yes #31, but only on R2 and R3 Rick don't go buying anything yet, we shall try to test with what you have now.
  13. dorke

    Amp keeps going into protection mode

    Please repeat the test of #32 this time with the DMM at AC 2V range.
  14. dorke

    opamcircuit output

    The answer is (C) =8. That is a hint for you, you should convince yourself that it is the correct answer. If you fail to do that you will not learn!
  15. dorke

    Does electron die?

    The current density for a given wire(fixed cross section), translates to current. If you apply voltage to a wire with a known resistance, you can calculate the current, but that is not important. That velocity of 2200Km/sec is not in a conducting wire, and not of a free electron.
  16. dorke

    Does electron die?

    Hop, "They[Electrons] move at about the same speed you can walk". They actually move much much slower than a snail...;) The drift velocity of electrons in a copper wire is in the order of 10E-5 m/S (1Ampere in a 2mm diameter ) It is dependent on the current density,the higher the current...
  17. dorke

    HELP WITH UNDERSTAND OF NAND GATE CIRCUIT?

    Yes, Must be the late hour...it also needs removing the inverter.
  18. dorke

    HELP WITH UNDERSTAND OF NAND GATE CIRCUIT?

    Hop, The circuit has one redundant oscillator. We can get the "same functionality" with just a single osc. e.g. here I eliminated osc#1, changed the LED location ,and the frequency to be about the samer as osc#1)
  19. dorke

    Does electron die?

    A video clip that may help you. EDIT: "Does electron die?" No. they incarnate...;)
  20. dorke

    HELP WITH UNDERSTAND OF NAND GATE CIRCUIT?

    Welcome to EP Nathan. The IC is a quad schmit-trigger NAND gate. IC1A and IC1B form a square wave oscillator,the purpose of the Rs and C is to set the Frequancy about 0.45 Hz with these R,C values. IC1C is an inverter. IC1D forms another oscillator with frequency of about 77Hz . For more...
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