Search results

  1. J

    1N4007 question

    Yes you are correct it is a constant current supply. And the voltage doesnt change even though I have the diode. I am guessing the constant current driver automatically adjusts to allow the small extra voltage for the diodes?
  2. J

    1N4007 question

    Thanks for your reply Steve, Driver 1 delivers 3.2V at around 1.3A. whereas driver 2 delivers 3.2V at around 0.6A. The regular 1N4007 on the positive output line of driver 2 seems fine in terms of letting current flow through and does not heat up much. Since Driver 1 is delivering a higher...
  3. J

    1N4007 question

    thanks guys, i bought a 3A Schottky Barrier Rectifier - 1N5820. It definitely works much better and hardly produces any heat that I can feel. I have a few questions about the Schottky Diode 1N5820, hope you guys can help. On the regular signal diodes, if I do a continuity test on it...
  4. J

    1N4007 question

    The diode that is connected to the positive line of driver 1 gets very hot i can only hold my finger on it for about 5 or 6 seconds. I believe driver 1 may require a higher rated diode because i think it is actually trying to push 1.8A through whereas driver 2 is pushing only 0.7A through hence...
  5. J

    1N4007 question

    I have 2 LED drivers that I want to drive my LED unit with. One driver is of higher constant current than the other. Both drivers will never be on at the same time. The output of driver 1 and the output of driver 2 will be joined together in parallel and then connected to the input of the LED...
  6. J

    Question about wire

    Just a quick question, can I use household 1 mm2 wire that is rated for 240V lighting use on a 12V lighting application to power a halogen bulb via a 12V car battery?
  7. J

    LED Buck Driver

    I agree with you about the fact that the circuit might try to overcompensate because it's adjusting all the time and by adding something that it's not designed for might just kill it prematurely. Another question, if a few LED's wired in parallel had something wrong with them and were on the...
  8. J

    LED Buck Driver

    I have a buck type LED driver that adjusts voltage output depending on whether I wire LED's in series or parallel. If i wire in parallel the voltage output is always 3.2V with a constant current output of 350mA, but if I wire them in series the voltage increases by 3.2V per LED. The intensity of...
  9. J

    Question about Capacitors

    sorry i think i've found the answer. it seems i do need a 22uF for the output because 22uF is higher than 0.22uF as 0.22uF will equal 220nF. just a quick question though: for the input of my regulator which the datasheet says i need 0.47uF for, what kind of capacitor would be best option...
  10. J

    Question about Capacitors

    Is a 22uF capacitor the same as a 0.22uF capacitor? reason I ask is that I am getting capacitors for my 12v regulator, and the datasheet for the regulator says I need 22uF on the output and 0.47uF on the input. But when buying the capacitors, i noticed some suppliers list as 0.22uF and some list...
  11. J

    extended and doubling switch buttons

    thanks, yeap i think thats what i am trying to achieve, parallel two switches :)
  12. J

    extended and doubling switch buttons

    i have a aftermarket car stereo, and i also managed to source a OEM style control unit that sits on the center console that has main buttons like next track etc. I want to open up the stereo and be able to tap into the buttons and use those buttons as extensions to the control unit. just...
  13. J

    Newbie - 12V Regulator Question

    Thanks CocaCola
  14. J

    Newbie - 12V Regulator Question

    Thanks. I've just found a pack of 22uF Low ESR 105°C Electrolytic Capacitors and the supplier says its definately suitable for application with my regulator. They say that because the ESR is low the cap will charge/discharge much faster which apparently is important for a regulator They are...
  15. J

    Newbie - 12V Regulator Question

    Thanks, I will get one and test what happens to the chip when the input voltage drops below 12.5V and do a test under load to see the heat generation. Also quick question regarding the capacitors to use. In the data sheet for the LM2940CT it says that a 0.41uF capacitor is needed on the input...
  16. J

    Newbie - 12V Regulator Question

    Thanks for your reply CocaCola, your a star. very much appreciate it. I will get myself one those low drop-outs that require 12.5 and see how it functions with a input below 12.5V. I will test and see but I am assuming lets say the car voltage is less than 12.5V and the regulator fails to...
  17. J

    Newbie - 12V Regulator Question

    Someone recommeded that I should use a 12V LM2940CT which is a low dropout regulator and specially designed for automotive use. Datasheet available here I've calculated that with this 12V regulator the max power loss in watts is 0.84W (assuming max input voltage=14.4V, output voltage = 12V...
  18. J

    Newbie - 12V Regulator Question

    I'm facing a bit of a dilemma here and hoping someone can help. My LED Constant Current driver has a Constant Current output of 350mA. The input for the driver is specified as 12Vdc (not a range, just 12v). I am using it on a car DC supply and because a car voltage is usually 13.8 - 14.4 volts...
  19. J

    Newbie - 12V Regulator Question

    Thanks for your replies. I was able to get the following information from the supplier about the LED driver (my driver is the first one which is 1-2W) Note: Supply up to 2pcs of 1W 350mA LEDs wired in series and total value of Vf should be under rated DC Voltage. But the thing is the LED's...
  20. J

    Newbie - 12V Regulator Question

    are the capacitors i am using with the regulators good enough for a 400mA current draw?
Top