Various diagram

Someone just got this trick works on all the uni body Mac Books and helps keep your wires and cord under control.



This clip is especially bendy if you are lounging on the sofa with the power-cord-side in towards the cushions. It keeps your MacBooks power cord under control with this trick and to stop it from tugging in you. Its built-in cable clip the one that keeps your cord wrapped around the power brick and clip it to the side of your laptops screen.

The cable pulls it up off your lap and keeps it neat and tidy not to mention free of crazy fall across the keyboard loops.

Build a Electronic Transistor Turns Op Amp On or Off Circuit Diagram. In this schema When transistor Q1 is switched off, the schema behaves as a voltage follower. By applying a positive voltage to the emitter of Q1 via a 10 KOhmhm resistor, the transistor is made to turn on and go into saturation. Thus, the lower end of R4 is connected to ground. 

The schema has not changed into that of a differential amplifier, except that the voltage difference is always 0 V. As long as the resistor ratios in the two branches around the op amp are in the same ratio, the output should be zero. A 47-KOhm resistor is used to null out any ratio errors so that the off attenuation is more than 60 dB. The high common-mode rejection ratio of a 741 enables this large attenuation to be obtained.

This is a simple Electronic Push-on Push-off Switch Circuit Diagram. Transistors Ql and Q2 make up the flip-flop while Q3 drives a reed relay. When power is first applied to the schema, Ql and Q3 are conducting and Q2 is cut off. Momentarily closing SI causes the flip-flop to switch states—Ql cuts off and Q2 conducts. When Q2 is conducting, its collector drops to around 0.6 volt. 

That prevents base current from flowing into Q3 so it is cut off, de-energizing relay Kl. The flip-flop changes state every time SI is pressed. Capacitors Cl and C2 ensure that Ql is always the transistor that turns on when power is first applied to the schema. When power is first applied to the basic flip-flop, the initial status is random—Ql and Q2 both try to conduct and, usually, the transistor with the higher gain will take control, reaching full conduction and cutting off the other one. 

However, differences in the values of the collector and coupling resistors will also influence the initial state at power-on. With C2 in the schema, it and R4 form an R-C network that slightly delays the rise in Q2s base voltage. That gives Ql sufficient time to reach saturation and thus take control.