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  1. Hero999

    How we can make this emergency lamp flicker

    Do you have the schematic for it? My guess is no, it can't easily be done because the tubes are probably wired in series to the inverter circuit. You'll probably need to rip out the inverter and replace it with a custom made unit.
  2. Hero999

    How i can connect this motion detector circuit to this emergency lamp

    I don't know where you get the patience from. I thought about responding, then I decided against it as the original poster doesn't seem to be making any effort to try to figure it out for himself. Of course you could add an additional transistor to control the siren, rather than having two...
  3. Hero999

    Guitar Aplifier

    Any of the semiconductors could have been damaged as well as some of the capacitors, especially C13 as it's connected directly across the power supply. Providing this project is not for sale, don't worry about it, just keep a supply of spares.
  4. Hero999

    I don't know what I"m doing wrong.......about to give up....

    No RS components are a totally different company to Radio Shack, they are a British based company, Radio Shack is US. RS components are a high quality supplier, Radio Shack, which used to exist in the UK under the name Tandy, sell overpriced crap. Yes, magazine paper works. I thought that the...
  5. Hero999

    Guitar Aplifier

    A quick test for an NPN transistor is to put the positive on the base and check for a 0.6V to 0.7V voltage drop when the negative is connected to either the collector or emitter. To test PNP transistors, just reverse the positive and negative connections. Unfortunately these tests aren't...
  6. Hero999

    I don't know what I"m doing wrong.......about to give up....

    Yes, temperature setting is critical. I found, that if it's too hot, the toner can smear and some of the magazine print can transfer, especially if too much pressure is used, too cool and the toner will never soften. Yes clean the board until it's really bright and shiny. Make sure that you...
  7. Hero999

    Guitar Aplifier

    The circuit failed because the input voltage was double what it was designed for. Look at the original schematic. The transformer's centre tap is connected to 0V so the voltage at either winding (with respective to 0V or neutral) will be 24VAC. The voltage at one winding will be 180
  8. Hero999

    Guitar Aplifier

    Using a non-tapped transformer and bridge rectifier won't make any difference so long as you reduced the secondary voltage to 24V. Which transistor failed? Simply blindly replacing it won't help, the chances are it'll fail again. There is potential for Q5 or Q6 to go in to thermal runaway...
  9. Hero999

    Guitar Aplifier

    Thanks for posting the PCB. It's still a good idea to check the schematic here against the original because lots of the schematics here have been copied incorrectly..
  10. Hero999

    0-30V Stabilized Power Supply

    No I don't think anyone does and if they did, you'd need to be sure that it's for the latest version and that you can get hold of all the components with exactly the same footprint.
  11. Hero999

    Guitar Aplifier

    I've never seen a 2200΅F capacitor, I presume it means 2200
  12. Hero999

    final year project: a blind stick that uses different sensors, help needed

    Use a parabolic reflector as I said above. You can take the reflector from a torch and replace the bulb with the temperature sensor. The compensator should be near the sensor but not enclosed within the reflector. It doesn't matter what type of sensors you have as long as they are as identical...
  13. Hero999

    wind/solar charge controller

    I'm building a flat pack piece of furniture, I have all the diagrams and instructions, the trouble is I've lost this screw and don't know what to do.
  14. Hero999

    final year project: a blind stick that uses different sensors, help needed

    Either of those sensors will work, each has its advantages and disadvantages. If you use only one temperature sensor and set it to sound an alarm only when it gets really hot (i.e. >50
  15. Hero999

    can anyone help me connect this circuit

    It depends on what you need to do I suppose. Do you want the light to just flash once when something is placed near the sonar's output or do you want it to stay flashing as long as something it near the sonar's output? Bear in mind that the sonar circuit needs to be isolated from the mains...
  16. Hero999

    final year project: a blind stick that uses different sensors, help needed

    You can also buy ultrasonic proximity sensor modules which turn on an output when an object is placed within a certain distance. For the thermistor circuit, you actually need two thermistors, one behind a parabolic reflector to sense radiant heat and the other sensing the air temperature, to...
  17. Hero999

    final year project: a blind stick that uses different sensors, help needed

    You can get pretty simple proximity sensors designed specifically for this type of thing - Google it. There are different types of proximity sensors, it's up to you but I'd recommend ultrasonic because they have the greatest range and are pretty accurate. Why use a PIC? Heck, I'd do this the...
  18. Hero999

    Battery low voltage cut-off problem

    Yes, there needs to be some hysteresis to prevent oscillation, just connect a 100k resistor between the op-amp's output and the + input. This will make the turn on voltage higher than the turn off voltage, see the data-sheet linked above for more information. I wouldn't use the LM324 anyway...
  19. Hero999

    Some articles

    It's probably just a bad ballast, just make sure you order exactly the same type. As the tube is black when unlit, it's a black light blue tube which is perfect for etching PCBs. For a decription of colour temperature and rendering index, see the following links...
  20. Hero999

    Some articles

    It might be that you used the wrong tube for the ballast. What colour what colour is the tube when off and when lit? A black light will be white when unlit and bright blue when lit, a black light blue with be very dark blue, almost black when unlit and deep violet/blue when lit: either a black...
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