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  1. Hero999

    555 timer designs using relay as output switch

    As I said before, the capacitor needs to be enormous for that to work. What's the resistance of the relay coil? Yes, the capacitor obviously has to be in parallel with the power supply otherwise the relay will turn off as soon as the power is disconnected. Even if it's high resistance reed...
  2. Hero999

    Checking Mosfets

    Why bother measuring it? It's easier to read the datasheet.
  3. Hero999

    Pirated content

    I think you're looking at this the wrong way. No one is actually stealing from you. If someone steals your car you can no longer use it. If another person copies stuff from your website you still have it, you've not physically lost anything. Someone else maybe making money from your work but...
  4. Hero999

    Pirated content

    If you look at the circuit you linked to on this site's blog, you'll find it's the other way round here: we copied them, rather than the other way round. Are you charging for people to visit your site? Do you have lots of advertising? And if so do you really think you'll loose that much...
  5. Hero999

    555 timer designs using relay as output switch

    http://datasheet.octopart.com/8600-0240-0000-Finder-datasheet-539064.pdf
  6. Hero999

    Grid Tie Inverter

    http://www.virtualvillage.co.uk/grid-tie-inverter-for-solar-panels-250w-230v-ac-007816-007.html?utm_source=googlebase&utm_medium=shcomp
  7. Hero999

    555 timer designs using relay as output switch

    The 555 isn't suitable for this because there's nothing to keep the relay powered when the power supply is removed. You could use a capacitor but the delay will be neither predictable nor easily adjustable. How long do you need the delay to last for? You'll need a very large capacitor for a...
  8. Hero999

    LOOKING FOR SERMINARS

    Sorry, no one knows what you're talking about. Posting in English rather than half Filipino might help.
  9. Hero999

    Countdown timer with alarm

    Where can you buy the LM3905 from? Have you built this circuit before? I think the LM3905 may be obsolete.
  10. Hero999

    Help please about the very simple power failure light project

    1) The voltage means nothing. It's possible to design a huge electric car which runs off 48V or a little wall clock which runs off 240VAC. Voltage alone equal power, look up Ohm's law. It's a silly idea, D1 to D5, R1 and C1 should all be removed and a 240VAC relay used. A 9V battery can easily...
  11. Hero999

    Variable Power Supply 0-25V/0-2.5A With LCD and Button Control

    1) How do we know what your requirements are? 2) It's better, cheaper and easier to just use double sided copper clad board in the first place rather than bodging a double sided PCB from two single sided PCBs. The main problem I can see with the circuit is the peak voltage from the rectifier...
  12. Hero999

    A Clean Output

    It sounds like you should make the safety system manual, i.e. the power needs to be disconnected when there are people in the area.
  13. Hero999

    Project requiring a PIC & timmer if it can not be programmed in the PIC

    The schematic will be the easy part. It's programming which is more complicated. I suggest you do some research into programming. BASIC is certainly the easiest language to learn and is available for most PIC MCUs. I sed assembler when I last had a go at programming a PIC and it wasn't that...
  14. Hero999

    12V 60W Amplifier

    Yes, you need a peak voltage of 21.9V to deliver 60W into 4 Ohms. It can be calculated using Ohm's law: P = VI I = V/R So: P = V*V/R  = V2/R Note, the above formulae relate to DC. The RMS power is half the peak power: PRMS = Vp2/(2R) Rearrange for Vp Vp = sqrt(PRMS2R) Vp = sqrt(60*2*4) =...
  15. Hero999

    Mixing Voltages

    The most efficient solution is to power the MCU from the regulator and everything else (relays, lights motors etc.) from the 12V. A 5V linear reglator running off 12V is only 42% efficient. Transistors are normally used in the way you've described to enable the MCU to control 12V appliances and...
  16. Hero999

    PCB Tracing

    You've not provided enough information. What does the PCB do? The made model number? Please post a picture.
  17. Hero999

    intergrated circuit information chart

    It's called Google.
  18. Hero999

    A Clean Output

    YOu haven't provided enough inofrmation. What do you men by fast? <1ms, 1us, 1ns 1ps? What level of safety you need? If it goes wrong, what's the worst that could happen? What's the SIL (Safety Integration Level)? Safety engineering is a complex subject, here are a few links to get you...
  19. Hero999

    A Clean Output

    1) Nothing. 2) What do you mean? It's an opto-TRIAC not a MOSFET coupler. 3) How about using a BJT? It's much easier. What frequency and duty cycleare you talking about? 4) Semiconductor outputs alone shouldn't be used in a safety critical situation. If the circuit is safety critical you need to...
  20. Hero999

    coin toss electronics by ic ne555-cd4017

    Here's another simpler decision maker circuit.
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