Search results

Search Forums New Posts
  1. C

    Need professionally made circuits to control heaters using PWM and MOSFET

    "No printed circuit board will be able to take the higher currents you want." What do you think all the 40 amp printed circuit boards are doing???????
  2. C

    Homemade DC generator(dynamo) with a spinning coil

    You will find it very difficult to light a globe with a filament. The best you will be able to do is illuminate a super-bright LED. When ever you spin a magnet you get AC. Slip rings also produces AC. You need a set of brushes and a commutator similar to a 3-pole motor to produce DC. This is...
  3. C

    Relay Behaving Strangely

    Put the two units on separate power supplies. Preferably batteries.
  4. C

    Need Help Improving Brightness in Multiplexed 7 Segments (6 Digits)

    6 digits is far too many for an outdoor display
  5. C

    Need Help Improving Brightness in Multiplexed 7 Segments (6 Digits)

    I have done the same thing but I use just 2 x 100mm displays per PIC chip. That's the only way to avoid all the disasters you are having.
  6. C

    lm7805 getting really, really hot

    7 x .8 = 5.6watts. Anything over 3 watts takes a lot of heatsink to keep the regulator cool.
  7. C

    SMPS Load Regulation

    ak Show me one youv'e made !!!!!!
  8. C

    SMPS Load Regulation

    Switch-mode is way beyond the average or even the advanced person. That's why they are NEVER released in any hobbyists magazines. The circuitry is just far too complex and even any of the projects simply use a switch-mode chip with the added external components. And then you start to talk...
  9. C

    Led fast past flasher

    You need 2 x 555 circuits One to time for 30 seconds The other to flash at 10 - 30 Hz.
  10. C

    Activate transistor with piezo disc

    The 1M is not needed the two diodes are doing nothing and the 10k is doing nothing and the 1k is doing nothing and the 220R and the 3k and the transistor. How much more do-nothing do you want??? It's a do-nothing circuit.
  11. C

    SMPS Load Regulation

    Why don't you buy a fully built and tested and perfected and guaranteed unit on eBay for $3.00 ???? The days of messing around have GONE !!!!
  12. C

    Beginner ... ferrite core coil for crystal set

    This circuit will not work: http://sci-toys.com/scitoys/scitoys/radio/closeup_two_coil_loop_crystal_radio.jpg Read my article and you will see why. It doesn't matter where the feedback winding is placed. It is not used in a crystal set. You can tune the stations by sliding the ferrite core...
  13. C

    Beginner ... ferrite core coil for crystal set

    You can see a very large article on Talking Electronics website Crystal Set - The NEW and it includes a frame aerial that is just as good as a ferrite rod but is much easier to make. It also shows how to make an adjustable "tuning capacitor" out of tin foil so you don't have to buy an...
  14. C

    Help in converting a wireless doorbell into a remote gate switch

    Simply remove the speaker and connect a diode and 100u to the lands and put 100k across the 100u.
  15. C

    Would anyone be interested in a £5 ($8) heart rate sensor?

    It's a heart-rate watch, $5.00 post free to anywhere in the world.You cannot buy a wrist-band for $5.00 !!
  16. C

    Would anyone be interested in a £5 ($8) heart rate sensor?

    You can already buy them for $5.00 with an LCD screen
  17. C

    cordless power tool converted

    You are not going to be able to run the saw from a power supply. The motor takes much more current than you think when cutting. The only way to use the saw is to connect it to a 24v battery and charge the battery via a power supply.
  18. C

    Trouble with solder

    You are worrying about the lead in solder and yet buy petrol with lead content and allow diesel cars to run on the roads that emit particles so fine that only recent tests have discovered them.
  19. C

    Trouble with solder

    The first thing you must remember is this: It's not the solder you want but the FLUX. It is the flux that does all the work. When the flux is heated it is just like a strong ACID. It EATS the scum and compounds and even the oxidization on and around the items you are intending to solder. At...
  20. C

    Trouble with solder

    "you are melting the solder but not hearing the joint." What is the joint saying ? Heat me ! Heat me ! Heat me !!
Top