Presets - A variable resistor, a resistor that has an adjustment knob of some sort like a slider on an audio board. Used for large voltage like a light dimmer, the preset is a item that is attached to your device that gives a precise amount of voltage to what it is attached too.
Linear variable resistor goes up from zero in a straight linge
Logarithmic takes awhile to taper off and then shoots up.
- Common to see three legs
- The legs are a collector an emitter and a base (EBC) to determine what the legs are get the data sheet
- Can be used as an amplifier or a switch which are the most common uses
- Two types of junctions, NPN or PNP
- NPN not pointing in on the circuit diagram
- Sourcing is pushing
- Syncing is to the ground
- Speakers, transducers, buzzers, and beepers
- Transduction is turning electrical energy into sound energy
- Transducers have a piece of crystal to vibrate to send sound
- One direction valve for electricity, controls the direction of electricity to stop kick back so devices don't burn up
- Light Dependent Resistor (LDR)(CDS)