Search results

Search Forums New Posts
  1. KrisBlueNZ

    Need heat sink for GBU806 bridge rectifier

    Hi Paul and welcome to Electronics Point :-) You need to show us the space it needs to fit into, with dimensions. Or you could have a look at the big e-tailers, Digi-Key and Mouser: http://www.digikey.com/product-search/en/fans-thermal-management/thermal-heat-sinks/1179752?stock=1&quantity=1...
  2. KrisBlueNZ

    Sound to light for my son's Dalek

    Hi there and welcome to Electronics Point :-) That circuit is not the best, but it should work. What is your power source? Is it rated to supply all of those lamps? Does the voltage drop when the lights are illuminated?
  3. KrisBlueNZ

    Magnavox ZV427MG9 vcr/dvd recorder ...is file recovery possible?

    If the recorder uses a standard file system on its hard drive (most don't, I believe), and you haven't recorded anything on to that hard drive since you deleted the recording, possibly. But not otherwise. Sorry :-(
  4. KrisBlueNZ

    3.5mm Jack with NC switch for on/off

    OK, thanks for the answers. Here's my suggestion. It uses a stereo jack socket with no switch. It works by applying a low DC voltage (about 0.7V), at a very low current, to the left and right contacts of the plug. When no headphones are plugged in, this voltage biases transistor Q1 ON, and it...
  5. KrisBlueNZ

    3.5mm Jack with NC switch for on/off

    Hi there and welcome to Electronics Point :-) There are several possibilities. You can get mono and stereo 3.5 mm jack sockets with fully isolated switches built in. These are a bit of a specialist item and I can't find any on the usual web sites - Digi-Key and Mouser, but you may be able to...
  6. KrisBlueNZ

    Radio transmission and one-wire, I2C, three wire and four wire protocols resource

    I've moved this thread from Circuit Help to Announcements, Site Problems and Feedback. I'm not sure about this idea, but if anyone wants to go with it, I can do the section on the Dallas one-wire protocol. And SPI as well, if no one else wants to do that. I'm not sure what you mean by...
  7. KrisBlueNZ

    American to UK electrics help needed urgently please

    Right. Equipment that has a universal power supply is normally specified with an input voltage range, e.g. 90~260VAC, rather than specific voltages like 117/230/240. But it is possible. In either case it will work in the UK, but as you say, if it's a universal input, there is no swtich setting...
  8. KrisBlueNZ

    American to UK electrics help needed urgently please

    pebe, read post #1 again. It clearly IS ok for 230V.
  9. KrisBlueNZ

    Simple NPN transistor circuit help

    LEDs require a certain amount of voltage across them before current starts to flow. Have a look at a typical VF vs. IF graph from a data sheet: This graph shows how the voltage across the LED is related to the current that will flow through the LED. The LED brightness is roughly proportional...
  10. KrisBlueNZ

    Repairing a Sony D-25 Discman

    Might be possible. Whip it open and have a look for obvious damage such as water damage or damage from being dropped.
  11. KrisBlueNZ

    American to UK electrics help needed urgently please

    Yes, that will work in the UK. American mains voltage is around 117V AC. UK mains voltage is around 230V AC. The power specifications say "AC 117/230/240V". That includes both of those voltages. It must have some automatic or manual way to select the voltage that it works from. This may be a...
  12. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    Yes, you can power the controller from the same supply that's powering the fans. Make sure it's a regulated supply, rated for at least 50% more output current than the total that will be drawn by the fans plus the controller (assume 100 mA for the controller). The controller won't draw more...
  13. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    Sure, it's a good idea to go with the kitset. It's designed to operate from any power supply of around 12V DC. In a car, it needs to be powered after the ignition switch so it doesn't flatten the battery when the car is not running. It won't need much current. 100 mA (0.1A) should be plenty...
  14. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    In case you decide to build a controller yourself, here's a design. I've included all of the Jaycar catalogue numbers. You would also need a piece of stripboard, Jaycar catalogue number HP9540. VR1 sets the temperature at which the fan will turn ON, and VR2 sets the hysteresis (deadband)...
  15. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    The temperature controller needs a power supply - since it's intended for automotive use, I assume this will be 12V DC. It has a 2-pin connector for connection to the temperature sensing device. And it has a 6-pin connector, which I assume is the control output connector and connects to the...
  16. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    Are you sure the fans draw only 0.5A? That's only 6 watts per fan, so they must be pretty small fans. The temperature controller has a relay on the board. It's the big black thing in the back left corner on the photo. It will handle at least 10 amps. Yes you're right about the fans and the...
  17. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    The adjustable one would be much better. With the fixed one, the OFF temperature isn't even specified. With the adjustable one, you can adjust the ON temperature AND the hysteresis (the distance between the ON temperature and the OFF temperture).
  18. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    How about this one: http://www.jaycar.com.au/productView.asp?ID=KC5381
  19. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    OK I'll draw something up.
  20. KrisBlueNZ

    Advice for starting a Project (Heat sensor switch)

    So are you saying that the fans will be powered from 12V DC? And what about the distance from the fans (and the controller) to the point where the temperature needs to be sensed?
Top