Contents
What does base resistance mean?
Generated current typically flows perpendicular to the cell surface from the bulk of the cell and then laterally through the top doped layer until it is collected at a top surface contact. The resistance and current of the base is assumed to be constant.
What does the base do in a transistor?
The base still controls current flow, but that current flows in the opposite direction — from emitter to collector. Instead of electrons, the emitter emits “holes” (a conceptual absence of electrons) which are collected by the collector. The transistor is kind of like an electron valve.
What resistance level should I use on a stationary bike?
Aim to maintain a cadence (measured on the cycle console in revolutions per minute or RPMs) of 80 to 100 RPMs on “flat ground” (low to moderate resistance) and 60 to 80 RPMs on “hills” (moderate to high resistance). If you find yourself struggling to maintain 60 RPMs, decrease the resistance.
What level should I use on a stationary bike?
| Machine Level / Watts | Time |
|---|---|
| Level 5 / 200 watts (high intensity) | 5 min. |
| Level 3 / 100 watts (moderate intensity) | 5 min. |
| Level 1 / 50 watts (low intensity) | 5 min. |
| Tip: Want to mix up your routine? Take an extra day this week to try out the bike’s pre-programmed modes, like Intervals, Hills, and Random. |
Why do you need a base resistor for a BJT?
The BJT is a voltage controlled device and hence current is not the driving factor for switching. The base resistor needs to be large enough to prevent damage to the transistor, but should still allow sufficient current to ensure the transistor switches on and off as per the base voltages.
Can a transistor not be used as a base resistor?
Not using a base resistor sometimes works, but it’s a terrible practice and it’s just asking for trouble. Relying on this mechanism runs the risk of burning out your I/O pin as well as damaging your transistor, so its recommended you use a base resistor.
What happens to the base of a transistor as voltage increases?
As the collector-emitter voltage is increased, the quasi-neutral width of the base decreases, so that it eventually becomes zero. The collector current becomes very large and no longer depends on the voltage applied to the base. This mode of operation is undesirable since most performance characteristics degrade as one approaches punchthrough.
What is the DC current gain of a base resistor?
This resistor determines the amount of saturation current I b (sat) flowing into the base junction, and that controls the amount of saturation current I c (sat) flowing through the collector and emitter junctions. For hard saturation, engineers usually use a DC current gain h FE value of 10.