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  1. chopnhack

    I'm back - a new circuit for the mini-golf course

    Lance, is there more to this circuit than one sensor? How does the system discern between the ball going in on the hole on the 2nd, 3rd or further strokes? Is there a sensor at the tee-off area of the final hole which is high and then rest of the circuit is live? (i.e. - first stroke would be...
  2. chopnhack

    Designing a Time Delayed Relay

    That's was a good catch - only pin 3,5,6,7 of both pic's have ADC inputs!
  3. chopnhack

    PCB track width and high current with Mosfets

    I ran it through the circuitcalculator and you could get down to a 20mm trace if you use a 4 oz. board. For the price of the board though...eep! Good question re: mosfet leg area. Another method that you could consider it over tinning the trace, I have read in a few places where this...
  4. chopnhack

    Designing a Time Delayed Relay

    I took them off :) Thanks for catching that, I forgot where I was in the schematic!! Hehe, green is go, red is stop ;-) Thanks again - I will try to find a different connector and then redo the layout. I am looking for the screw down type terminals, fewer components and lower cost. Once...
  5. chopnhack

    Why did the designer put a 350v cap when the max voltage of circuit is 20v?

    My uneducated guess would be one of a few reasons: supply on hand, schematics were drawn up to include parts already owned or a simple typographical error - an extra zero or a missed decimal point. How large a value does the secondary produce before feeding the bridge?
  6. chopnhack

    Designing a Time Delayed Relay

    I think I understand, see schematic below: J2 would be the cathode side of the LED. Thanks for the explanation on the PIC programming/pin layout as well as the reason why the LED placement change! LED - Do you know if its a T1 3/4 size? It mentions 5mm and the specs match a similar LED marked...
  7. chopnhack

    Need help with I hope simple project!

    Tom, I won't be able to provide much help, but a question came up: How do you currently change the mode? It would seem terribly inconvenient to have to turn off the bike to change the mode. Perhaps in addition to the status light project maybe you can wire up a 4 position? switch: Off, + each...
  8. chopnhack

    Designing a Time Delayed Relay

    I had completely missed this!!! :oops: Ok, got it :) Can you explain why you can't connect the Allegro to one of those pins, but you can connect the transistor? When I looked at the chip for an analog channel, I passed up on pins 6 and 7 because they were programming pins and I didn't think...
  9. chopnhack

    Making $$$$ out of your electronics business?

    I believe you need a balance of both. Inventiveness is not something necessarily innate to a person. Many times, people without "imagination" come up with solutions to their problems which then become useful "inventions". There are many hobbyist that are probably more knowledgeable than Dr's...
  10. chopnhack

    Designing a Time Delayed Relay

    I redid the schematic as you suggested with the second Allegro chip, but had some questions: Pin 7 of the 2nd Allegro (U3) is the ratiometric output which needs to go to the ADC of the PIC - If I use pin 5 of the PIC, do I keep C7 and R4 or do those get omitted? Can the C4 decoupling capacitor...
  11. chopnhack

    Designing a Time Delayed Relay

    Yes. Sorry, I didn't follow at first, but now realize that the PIC's logic control capabilities serves as the switch and the means of controlling the relay's outcome. In this case it would be an OR statement, when either outlet is loaded, switch on. Thanks! The first PIC is 1/2 the cost of the...
  12. chopnhack

    Designing a Time Delayed Relay

    No problem, this project has had some design creep, LOL That is what I concluded too, there is a short in that diagram that I can not reconcile, so two circuits it is. Agreed, however, the relay is common to the two circuits - how do I ensure that two loads are not used simultaneously - other...
  13. chopnhack

    Designing a Time Delayed Relay

    I thought you said your PCB skills were rusty!!! Wow, you got me beat and in one take, well done! I love how you were able to resolve many of the connections into common planes - I tried to work that out, but was getting tied up in the rat's nest too often. I like how you cheated some space...
  14. chopnhack

    Evaluating a cap. power supply in LTSpice

    I found it cool how they derived the values - I thought they were arbitrary, but it turns out its based on the tolerance. i.e. E6 has 20% tolerance so the difference in steps of value is determined by 20% of the preceding value. Very cool! Can you show me how? I used LTSpice, but when I probe...
  15. chopnhack

    Designing a Time Delayed Relay

    Looking with fresh eyes, I would have to say that the diagram shows the bottom leg of the 220 circuit will cross over to the 110 circuit. The only way I see of making this work would be to either some how switch the incoming sources (110 and 220 separately) or forgo that and use two boards. I am...
  16. chopnhack

    Evaluating a cap. power supply in LTSpice

    Ok, here is what I got: I used the formula R = (Vs - Vf)/If to come up with a 410 ohm resistor. At one point I had an average v.pot. reading of 10.4 and I used 2.2 as my v. drop across the LED divided by the 20mA continuous current required for the device. For some reason when I refreshed the...
  17. chopnhack

    Evaluating a cap. power supply in LTSpice

    Thanks Kris!! I had the wrong settings for the simulation, I just redid the schematic and was able to see the different nodes and play with the resistance variables. Very cool tool :-) As for brightness, I see why you said to use a higher efficiency LED, within the limitations of this...
  18. chopnhack

    Evaluating a cap. power supply in LTSpice

    LOL calculus was some ages ago, you are more likely to find me with a sheet of graph paper shading in triangles under the curve :eek::rolleyes::D
  19. chopnhack

    Evaluating a cap. power supply in LTSpice

    Thanks Kris! Understood :) I completely followed that! Being able to visualize the path of current is very exciting for me, I have always wanted to understand "how" these circuits worked, understanding that most discretes are little more than switches, being able to follow the path starts with...
  20. chopnhack

    Evaluating a cap. power supply in LTSpice

    I need to run a LED as an indicator light when a switch is thrown by a irrigation control system. The switch shows 10VAC when closed. Would using a capacitor power supply be my simplest way of powering the LED off of the 10VAC? I tried to evaluate the system in question on LTSpice, but the...
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