Pnp Transistor Led Driver. Here the ground refers to the negative line for an npn and the positive line for a pnp bjt. Brief description on bc558 bc558 is a pnp transistor hence the collector and emitter will be closed forward biased when the base pin is held at ground and will be opened reverse biased when a signal is provided to base pin.
Dark detecting led driver circuit to add darkness detecting capability to a solar circuit is easy because the solar panel can directly serve as a sensor to tell when it s dark outside. Going from a back view the first lead is the emitter the second lead is the base and the third lead is the collector. High current accuracy and stabilized output currents of 10 50 ma.
Here the ground refers to the negative line for an npn and the positive line for a pnp bjt.
An led driver is an electronic circuit that utilises a transistor to switch power to an led. Here the ground refers to the negative line for an npn and the positive line for a pnp bjt. If the led has a higher power requirement then it is best to use an npn transistor as a driver. Led driver consisting of a resistor equipped pnp transistor with two diodes on one chip in a small sot23 plastic package.
