Push factors or pull factors are factors in which would make one individual want to move out of certain areas (called push factors) and factors that would make one person attracted to another area (called pull factors). Push and pull factors may vary from place to place, and may also depend on the individual's opinions. Common push factors may range from poverty, famine, bullying, discrimination, war, and even difficulty in finding courtship. Pull factors may range from high income, more food services, low crime rates, anti-discrimination laws, less bullying, and peace
The business terms push and pull originated in the marketing and advertising world, but are also applicable in the world of electronic content and supply chain management. The push/pull relationship is that between a product or piece of information and who is moving it. A customer "pulls" things towards themselves, while a producer "pushes" things toward customers
An arrangement used in power amplifiers; a positive voltage in the input causes the current to rise in one transistor, whereas a negative voltage does the same for for another transistor Push-pull amplifiers usually have output transformer
Most common type of amplification that amplifies the negative and positive sides of the waveform separately Allows for much higher power output than single-ended
A type of amplification circuit in which two (or more) identical tubes or transistors each amplify in such a way that when one tube (or transistor) is operating on a positive alternation, the other operates on a negative alternation 'Push-pull' amplifiers are able to provide much higher power output with significantly lower overall measurable distortion than 'single-ended' amplifiers
In a push-pull amplifier, the power supply is connected to the center-tap of the transformer and a tube is connected to both the upper and lower end of the center-tapped primary This allows the tubes to conduct on alternate cycles of the input waveform A push-pull stage can be biased class A, where current flows in both tubes for the entire input cycle (but in opposite directions), or class AB, where current flows alternately in both halves, but less than a full cycle in each, or class B, where current flows only half the time in each tube Most designs are biased class AB for best efficiency and power output with minimal crossover distortion (but not necessarily best "tone", although this is subjective) A push-pull stage requires at least two tubes to operate, but can have more connected in parallel with each side, resulting in an amp with four, six, or even eight output tubes for higher-power amps This is called "parallel push-pull" operation, or PPP