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  1. Hero999

    componant sources

    It depends on where you live. Here in the UK, Maplin, RS Components, Farnel and Rapid are the most popular suppliers. Farnel are good because they don't charge for delivery, even for small orders. RS also don't charge for the delivery of small orders if you have a credit account with them...
  2. Hero999

    0-30V Stabilized Power Supply

    Oh you're talking about the output voltage, I thoguht you were refering to the voltage on the filter capacitor.
  3. Hero999

    linear pots

    Most potentiometers are linear. A linear potentiometer's resistance is directly proportional to the wiper's position. There are also logarithmic potentiometers which is have an exponential/logarithmic (depending on which side of the wiper is being measured) resistance-wiper position...
  4. Hero999

    gating rf frequencies

    There's no need for a solid state relay. The signal is AC and the voltage swing is less than the power supply voltage so you can bias the signal at half the power supply voltage and AC couple the input and output via suitably sized capacitors.
  5. Hero999

    cordless phone

    I have a problem with my car. Is it the battery that's bad or the ignition coil?
  6. Hero999

    gating rf frequencies

    The gate switch should never go above of below the negative rail. It should be connected to 0V to turn off and +V to turn on and should never be left floating. An analogue switch is not a solid state relay. The signal being switched should always have a voltage within the supply voltage range...
  7. Hero999

    0-30V Stabilized Power Supply

    No, the voltage on the capacitor will be about 32.5V with a 24V transformer.
  8. Hero999

    datasheet

    That makes sense. The original poster really needs to learn how to use alldatasheet.com, datasheetarchive.com,  Google etc.
  9. Hero999

    gating rf frequencies

    What about tuning the RF oscillator on and off?
  10. Hero999

    How To Get 250vdc at 1.5a from our Variac

    He's probably right though, normally lethal voltages at lethal currents aren't allowed at these events. I bet you weren't allowed to generate dangerous amounts of hydrogen gas. If wasn't a Brown's gas improve the efficiency of your car project was it? ::) Anyway, back to your original...
  11. Hero999

    datasheet

    It's not found on Google. It looks like a relay, I doubt you'll be able to get a datasheet for it but you can probably easily figure out the pin out using a multimeter. If it's not a relay, then I have a feeling, it could be an IF filter, probably 455kHz. What does the board do? How about...
  12. Hero999

    Attack site

    Anti-virus doesn't give as much protection as most people think. Don't forget that before a an anti-virus program can detect and remove a virus, the programmers need a sample of it, which they only normally get hold of after the virus has infected 1000s of computers. Memory resident virus...
  13. Hero999

    uestion about the operation of photodiode

    What are EHPs? A simple transimpedance amplifier can be made using an op-amp and a resistor.
  14. Hero999

    Capacitor as battery

    It depends on the holding voltage of the solenoid and how long it needs to be on for. Use the following formula to calculate the capacitor size: C = t
  15. Hero999

    Attack site

    The problem has now been solved. Google periodically scans all sites it crawls for viruses and adds any bad sites to a blacklist. Firefox has a security feature which automatically blocks blacklisted sites, therefore reducing the risk of getting a virus. The text now appears on the screen much...
  16. Hero999

    Attack site

    It seems like Electronics Lab has been reported as an attack site. Every time I visit this place I get the following warning from Firefox, see attached. I wonder if this is because of the amount of spam that the bots post here? One thing I have noticed is that this site does seem to be slower...
  17. Hero999

    My latest PCB.

    I've assembled the PCB now. I haven't tested it yet though.
  18. Hero999

    Re: UltraSonic Radar

    Please don't spam the forum by asking the same question three times. Well, to be picky, there's no such thing as ultrasound radar; detecting object with sound is sonar, radar uses microwaves. Read the second reply to this thread: audioguru posted a link to a sonar project on this site. I have...
  19. Hero999

    My latest PCB.

    Yes, I've seen many proprietary silk screen products but I've never used them. They look nice but they're also more expensive than simple toner transfer. I think black is fine for a silk screen, it does the job and I've seen professional PCBs with a black silk screen. Here's a link to the...
  20. Hero999

    Fm transmitter

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