automotive bulb load

Discussion in 'The Projects Forum' started by mah, Nov 7, 2013.

  1. mah

    Thread Starter Active Member

    Mar 15, 2010
    276
    2
    I have this automotive bulb 12V 75/75CP P45t , its in candle power not watt , so can it be loaded to 150 watt photovoltaic panel ?
    i have read on google that cp can't be converted to watt , do you think 75 cp is close to 55 or 60 watt in withstanding ?
    [​IMG]
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
  3. mah

    Thread Starter Active Member

    Mar 15, 2010
    276
    2
    the lamp you pointed to is for NARVA but my lamp is flosser , what is the relation between p45t and the power it can load.?
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Last edited: Nov 7, 2013
  5. mah

    Thread Starter Active Member

    Mar 15, 2010
    276
    2
  6. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
  7. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,290
    1,255
    It looks like it might also be 75 watts, so the panel probably won't be able to get it going because the cold resistance will be very low.
     
  8. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    He could have built the electronic load I designed for him and done his experiment three times by now. :mad:
     
    killivolt likes this.
  9. #12

    Expert

    Nov 30, 2010
    16,302
    6,812
    There are always some people that don't want to do it, "my" way. When I start feeling irritated about it, I take a break from AAC because the real problem is that I feel over-invested. Sometimes that takes a few weeks.

    Of course, you can choose whatever method or combination of methods you want. I only wish success for you.
     
    JohnInTX and Bernard like this.
  10. mah

    Thread Starter Active Member

    Mar 15, 2010
    276
    2
    thanks to MikeML ,I connected two bulbs in series as load to the panel and it works but it wasn't of full power , i measured volt and current and it give about 30 watt over every lamp . i don't know they could withstand more if the panel power increased.
     
  11. mah

    Thread Starter Active Member

    Mar 15, 2010
    276
    2
  12. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    This came up on another thread a while back. I tested a 12v 50W bulb, and found the filament would light reliably from any current over about 40% of the normal running current, so the 12v 50W (4 amp) bulb would light from any current over approx 1.6 amps.

    A couple of other 12v bulbs performed very similarly.

    Although the cold resistance value of the element is very low, >=40% of rated current is enough to get the filament metal over the thermal runaway point where it starts to glow (and its resistance then jumps right up).
     
  13. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,290
    1,255
    Yes, I think now about what the IV curve looks like and there is current to heat it up. Interesting. :)
     
Loading...