Search results

Search Forums New Posts
  1. dorke

    TLC5940 + TIP120

    Welcome to EP. A few things I don't understand: 1. What is the current needed for your LED Chain,is it 20ma? 2. Why do you need the TIP120s for? 3. Where have you connected the "pull-up" ,and why? 4. Please post a simple diagram of your output connection to the LED chains.
  2. dorke

    Oscillator

    Yes it does , it is a 14 stage divider and another FF is needed to get it to 15 . But,this FF can be merged easily in the clock design.
  3. dorke

    Clean square waves using a 555 timer?

    It is actually very simple to explain. The main difference between the non-working and working circuits is the load connected to the output pin 3. In the working one there is no load(I guess ,because you didn't show that pin 3 in your diagram). In the case of the non-working there is a load an...
  4. dorke

    Clean square waves using a 555 timer?

    1. The capacitor is connected in the "failing circuit ",but isn't connected properly. It should be like this: Disconnect the black wire as shown . Connect the capacitor with the shortest possible leads directly between pins 5 and 1. 2. About the use of the scope probe. The simple answer is...
  5. dorke

    Data Selector Inverters And Nand Gates

    ??? Any of the terms you use doesn't make any sense.o_O
  6. dorke

    Oscillator

    @Hop, I wouldn't go the AC line way. 1. It is not accurate at all about ±5% 2. It is relatively expansive(transformer) The way to go is with a CD4060 + 32.768kHz clock crystal (dirt cheap,and may be yanked out of a broken digital clock-almost all of them have one)
  7. dorke

    Killing SSR (relays) - Need to understand

    About the heat issue: 1. Looking at the fan vs. the heat-sink location it is clear that most air blown by the fan doesn't go through the fins, it therefore will not cool the SSR very efficiently.That needs to be corrected. 2. If possible I would take the fan +SSR+haetsink outside of the...
  8. dorke

    Clean square waves using a 555 timer?

    First thing that has to be said: "breadboards are nasty things for fast switching circuits" They are easy to assemble,modify and reuse but the results are poor. Better use the "dead-bug method" for better results. And a note: What you are seeing is ringing of the output signal manifested in...
  9. dorke

    Clean square waves using a 555 timer?

    Adam, The frequency of the oscillator will have no effect on phenomena. The problem is due to the output switching states(transient). This will be the same regardless of any specific frequency. 1.The main thing is the switching glitch on the PS . 2.Probable reflections on the output line.
  10. dorke

    Clean square waves using a 555 timer?

    True, But if we need the full scope sensitivity, while probing a low level signal ,we have to use the X1 probe. Not directly to the input itself,with the probe.
  11. dorke

    Circuit design help needed

    So you have 5 different square waves at various frequencies. Are they all present at all times ,or do you create the needed one only when it is needed? The Power ON/OFF is a simple switch on the battery voltage. The Enable Output can be merged with the ON/OFF switch.
  12. dorke

    Circuit design help needed

    Welcome to EP. Please explain what do you mean by: "oscillate the same bank of LEDs but at 5 different preset frequencies".
  13. dorke

    Any Idea how to solve this question?

    Google " first order passive high pass filter"
  14. dorke

    Minecraft 4-bit CPU.

    That is not very complicated. You need to define the representation method of negative numbers (Lets assume 2's compliment). This will usually "eat up" one bit of the 4bits for the sign bit . You need a 4 bit adder,with a carry input. Two 4bits registers to hold the values A and B. The result...
  15. dorke

    Connector type?

    Welcome to EP. It looks similar to the H7 car light bulb,but probably isn't that. What does it connect to? Please post a link to the cable in your photo.
  16. dorke

    2 Stage BJT (Potential Divider Biased) design

    Welcome to EP. What is the problem you have with designing those 2 circuits? They are straight foreword,is this homework? One important issue missing is the frequency range required. and another issue is the value of RL .
  17. dorke

    from dimmer to switch (without mass?)

    Yes, One to "L" the other to "A1" (or "A2") When the switch is closed the brown and black are connected supplying the "Live feed" to the lamp.
  18. dorke

    Clean square waves using a 555 timer?

    Please post a photo of the actual build, it is very important!
  19. dorke

    Chip`s plastic protection removing ?

    Set the gun to 260 Celsius and try it on a corner of the IC pins with the blue stuff(till the solder melts).
  20. dorke

    Chip`s plastic protection removing ?

    O.K. If you need to reflow it ,you should use a heat gun with adjustable/controllable temperature. Do you know how to remove/reflow an IC like it?
Top