Search results

Search Forums New Posts
  1. J

    How to pick a potenciometer or resister?

    Sulfation is only a process by which lead acid batteries lose the ability to accept a charge because of the build up of lead sulfate on the plates. Up until your last post no one here assumed you were talking about those types of batteries. I hope you don't think that other forms of batteries...
  2. J

    Help please. I built my NOR gate schematic

    http://en.wikibooks.org/wiki/Electronics/CMOS CMOS has an advantage over a typical NMOS type gate. I guess the real question is why he chose to design that NOR gate with complimentary mosfets and why he decided to ask here how it looked. He does have the transistors switched around though That...
  3. J

    Help please. I built my NOR gate schematic

    You must have missed this enormous picture? http://en.wikipedia.org/wiki/File:Cmosunbuff.png I would say you where on the right track fckiri
  4. J

    is your math any better then mine???

    Oh never mind, I think I got it. Since I know the angle and the opposite side, then TOA formula is involved. eg. tan 30 = 2/a a = 2/tan 30 a = 3.46 3.46^2 * 2^2 = 16 sqrt(16) = 4 a = 3.46 o = 2 h = 4 Oh I remember now.
  5. J

    is your math any better then mine???

    I need some help, school failed me or it has just been so long that I have become stupid. Latter being the more likely. ;) So please HELP!!!!! I need to put in a chimney pipe, and I want to buy my chimney pipe. But I am having a hard time figuring out the length of the piece between the two...
  6. J

    Electronic Siren problem

    Have you checked to make sure your lm741 swap out was a direct and exact replacement for the lm324 without modification to the circuit? I would also like to see a picture of your breadboard layout.
  7. J

    How to pick a potenciometer or resister?

    I don't understand, the sensing circuit shuts down the charging of the battery bank when the voltage nears the maximum? The Alternator is meant to have a higher output then the battery bank or current would not flow and the batteries would not charge. If you add all that up and add in a thin...
  8. J

    online skype graphic is not downloading

    Whenever I see steve online, he always messes up my browsers formatting. I get this huge box under his name with the default graphic. So either the graphic is not on the server or I would presume a bad link. Anyway, not something that bothers me a ton, but been this way for a while.
  9. J

    lm317 set up

    http://en.wikipedia.org/wiki/Lithium-ion_battery#Charging_procedure Most lithium ion battery chargers have protection circuits to make sure the temp stays in check. Plus, you can really ruin a lithium-ion battery as the wiki states by discharging it past a certain point. There is no advantage...
  10. J

    Query about tools required

    davenn, you got a video of how you use side-cutters to strip 22 gauge wire? I am being serious too, I have never had very good luck. I cheat and use my lighter' edit...
  11. J

    lm317 set up

    I am just gonna say this again. you are using lithium ion battery cells. these are VERY picky about how they are recharged. I don't think TCB's design takes into account a lithium-ion cell. Too much heat and you won't have much left of your project.
  12. J

    12v lithium-ion battery pack circuit board problem

    I am gonna agree with you, that bare copper wire laying across all those metal spots on the circuit board certainly isn't helping you any. Did you use flux when you re-soldered the wire? Looks like you got it quite hot as well.
  13. J

    what do i need to make a motor timer/controller?

    Just for clarification, if you took and deleted everything except for R7 and C3, to the left of the 555. It is exactly the same design as you already have except it is only driving one output ATM.
  14. J

    Help w/ Looping a Rec Module

    He isn't using the 555 in a one shot setup?
  15. J

    lm317 set up

    oh and I would listen to TedA about the batteries. I don't really know a lot about battery charging, you certainly don't want them to blow up, so you will have to find out how much current they can handle and how much your solar panels provide as Ted has already hinted at. Sorry I can't be of...
  16. J

    lm317 set up

    go to advanced edit and then down on manage attachments, click on remove button That picture up above, unless you have figured it out is still wrong. But is that why you want to remove the picture? The transistor in the above schematic is gonna create a short between vcc and ground when the...
  17. J

    lm317 set up

    This is what I had in mind... I didn't say you couldn't have your photocells in parallel, I just said to put them in series with the collector. My fault, but this is what I meant R1 ideally will be a variable resistor, but since my cad app don't have photocells I replaced that with a variable...
  18. J

    lm317 set up

    Right now the transistor is not doing anything "useful" in this circuit. It is not acting as a switch, which is what I was thinking you had in mind. Right now, the photoresistor will take the full load of the current for both led's. You need to put the LED's in series with the collector.
  19. J

    what do i need to make a motor timer/controller?

    a normal relay is just what you think it is. They make other special kinds that steve is trying to say you will not need. If you are using a 12Vdc supply then you will need relay with coils that work on 12Vdc.
  20. J

    lm317 set up

    You have the +6V connected to the output of the LM317, how do you expect it to be regulated in this configuration? Take a closer look at the datasheet. It also seems like the photoresistor should be attached to ground as well. This would then make a voltage dividing network at the base of the...
Top