![]() ![]() The zener diode is doing all it can to hold the output voltage at the output level for the device, even in the face of large input voltage. Diode I-V characteristic curve (wikibooks) There key here is that the zener diode is reverse-biased and operating in its breakdown mode. This lab will have both a SPICE model and a practical circuit demonstration. To keep things simple, the input voltage will be +9V DC, which anyone can obtain with a simple 9V battery. For the zener diode device, I selected a 1N4278, which is a 3.3V zener diode rated at 1W. In order to select the right value for the resistor, I consulted the 1N4278 datasheet for the values Vz and Iz. Vz for the 1N4278 is of course 3.3V, and Iz, the breakdown current threshold, is 76 mA. With these values I could then calculate the acceptable resistor value. The resistor needs to be under 75-ohms, plus or minus our tolerances. From my resistor grab bag, I selected a 47-ohm resistor to begin the experiment. To model this circuit with SPICE, we only need three components: the input source, the resistor, and the zener diode. The SPICE model for MacSpice is shown below. The SPICE model performs a DC sweep on the 9V input source, starting from 0V and increasing to +9V in 0.5V increments. The output of the DC sweep is shown below. Circuit: * Zener Diode Voltage RegulatorĭC transfer characteristic Mon May 16 23:30:20 2011Īs can be seen from the output, when the input source is reaches a level above +3.3V, the zener diode, which is reverse biased, see this as -3.3V and opens the flood gates for the zener current. In the picture below, the 47-ohm resistor is the horizontal device, and the diode is the vertical device to the right. I hooked up my multimeter to the output port of the zener regulator, as expected enough the output voltage was 3.309V. For daytime, I apply a tiny bit of balm to my lips to diffuse the colour.With such a large voltage drop over the small 47-ohm resistor, it heats up very quickly after all, that difference in energy has to be dissipated somehow, and the resistor dissipates energy via heat. It's neutral enough that it won't look out of place at a lunch but it's just bold enough that it can be a statement evening look too. I keep this shade in my handbag at all times because I know it will always complement whatever makeup look I'm wearing that day.įinally, Spice is a great day-to-night shade. Maybe you've gone with some sparkly and glittery gold and bronze tones? Well, Spice works with that too. If you've created a simple feline flick, Spice is a great complement. It's the miracle blend of all the classic lipstick staples in one gorgeous shade, making it the perfect neutral but with a twist!Īnother reason you need to get this lip pencil back in rotation is because it literally matches every eyeshadow look you can imagine. Spice is a little bit red, a little bit pink, a little bit brown and a little bit nude. Next, the colour is a perfect mixture of tones. It looks very different on every person and yet it manages to suit us all. But I've seen it work as a gorgeous sooty red colour on fairer skin and a beautiful complementary neutral on deeper skin tones. On my caramel skin Spice looks like the perfect deep pink-brown nude colour. This quintessential 90s lip liner should not just be for makeup nostalgia! MAC Spice is a makeup bag staple and if you've happened to leave yours in the bottom of a drawer somewhere, here's why you need to dig it up.įirstly MAC's Spice pencil somehow manages to suits all skin tones. Image: Pinterest Here's why this old favourite needs to make its way back to the top of your makeup bag. ![]() All international money transfer services.High interest savings accounts Australia.
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