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ArcticMyst Security by Avery
blu ray driver not putting out enough mA
- Thread starter busterhax
- Start date
That's fine. When you're measuring voltage where the diode should go, but without a dummy load, the circuit will show almost the supply voltage. Like any semiconductor device, at a very low current, the LM317 will have a very low voltage drop.
Now we need a proper dummy load. Do you have a few leds? If so, what kind? If not, do you have an extra 100 Ohm resistor?
Now we need a proper dummy load. Do you have a few leds? If so, what kind? If not, do you have an extra 100 Ohm resistor?
Looks like you're ready to try that BluRay. Start by disconnection the batter, then short out the capacitor, now wait 15 seconds and short out the capacitor, then short out the capacitor ( I promise I'm not just being funny) turn the pot to max resistance, now connect the LD, and finally the battery.
Then slowly turn down the pot until it reached laseing threshold, then disconnect the battery. Mark the position of the pot, measure the resistance across the pot and fixed resistors, and post here! ;D
Then slowly turn down the pot until it reached laseing threshold, then disconnect the battery. Mark the position of the pot, measure the resistance across the pot and fixed resistors, and post here! ;D
Oh, you'll know.
It will go:
dim, so I'll turn it up a little
still dim, so I'll turn it up a little
a little brighter than dim, so I'll turn it up a little
just a tiny bit brighter, so I'll turn it up a little
AHHHHHHHHHHHHHHH!!!!!!!!!!! IT WORKS!!!!!!! HAPPY DANCE!!!!!!!!
^That will be the threshold.
Use a piece of A4 paper as a target.
It will go:
dim, so I'll turn it up a little
still dim, so I'll turn it up a little
a little brighter than dim, so I'll turn it up a little
just a tiny bit brighter, so I'll turn it up a little
AHHHHHHHHHHHHHHH!!!!!!!!!!! IT WORKS!!!!!!! HAPPY DANCE!!!!!!!!
^That will be the threshold.
Use a piece of A4 paper as a target.
oops sorry. no. i started at max resistance, as i turned the pot down, it got brighter and brighter. it never dimmed like you stated. i reached the lowest i could on the pot and it still never dimmed, just very very bright. there was 62mA going through the diode. should i stop there or should i keep playing with the resistors until i find the threshold?
voltage drop was 1.14 volts.
i thought you were saying to keep turning the pot down until the beam suddenly went from bright to very dim, then turn it back again until it was suddenly bright again. i guess should i keep running it at 62mA? that seems pretty dangerous compared to other setups
i thought you were saying to keep turning the pot down until the beam suddenly went from bright to very dim, then turn it back again until it was suddenly bright again. i guess should i keep running it at 62mA? that seems pretty dangerous compared to other setups
Saved by low battery voltage again! If there is not 1.25V difference between the Vout and Adj pins, the regulator is dropping out.
I think what confused you was my saying 'turn it down' instead of 'reduce the resistance of the potentiometer' Again I am sorry, but glad that no damage was done.
What battery are you using? a PP3? If so, turn the pot to the max resistance, then change the battery.
I think what confused you was my saying 'turn it down' instead of 'reduce the resistance of the potentiometer' Again I am sorry, but glad that no damage was done.
What battery are you using? a PP3? If so, turn the pot to the max resistance, then change the battery.
