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I am trying to switch an LCD display from a micro port .
My circuit works fine without a load .
When I use LCD as a load the transistor does not turn off and instead 0vdc
I get 3.75VDC.
I tried 10K resistor across the load but same problem
I would appreciate if someone could explain me the reason for the problem and suitable solution .
If bipolar is not a suitable solution I will consider using N MOSFET
- Circuit to switch a load using Bipolar transistor
- Switching LCD.jpg (94.79 KiB) Viewed 1123 times
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- Joined: Sun May 06, 2012 9:45 am
The feed from the micro to Q2 base should include a resistor to limit the base current. Perhaps Q2 has been damaged and has gone s/c from emitter to collector and is keeping Q1 switched on.
Other than that, there is no reason for the circuit not to work
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