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x0x:powersupply [2010/09/02 16:25] ihatetoregister |
x0x:powersupply [2010/09/02 16:52] ihatetoregister |
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- | The power input into the x0xb0x is 9 V alternating current. This needs to be converted to direct current, before getting regulated to its proper voltage. This is done by the four 1N4001 diodes with what is called a bridge rectifier. You can see how a bridge rectifier works on the left hand side. While the bridge rectifier has in fact made sure our current is DC, it is in a state called "Full Wave Varying DC". We don't have a smooth line of direct current, rather, we have a series of camel humps, where the voltage goes from 0 V, to +9 V back to 0 V. | + | The power input into the x0xb0x is 9 volt alternating current from an AC/AC adaptor. This needs to be converted to direct current before getting regulated to the different voltages. The 9 volt input is a root mean square value (rms) and is the value that is shown on a multimeter with the ac measuring setting. This means that the peak to peak voltage is 9 volts times the square root of two resulting in a peak to peak value of about 12.7 volt. Due to differences in ac adaptors the rms voltage could be over 10 volts resulting in a peak to peak voltage of about 14-15 volts. |
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+ | The ac/dc conversion is done by the four 1N4001 diodes with what is called a bridge rectifier. You can see how a bridge rectifier works on the left hand side. While the bridge rectifier has in fact made sure our current is DC, it is in a state called "full wave varying DC". We don't have a smooth line of direct current, rather, we have a series of camel humps, where the voltage goes from zero, to the peak voltage back to zero. | ||
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+ | The two 2.2 mF capacitors c3 and c5 perform a smoothing operation. When the voltage starts on its downward drop from the peak voltage to zero, the capacitors discharge, and the voltage drop is minimized. The DC waveform looks a lot smoother, and more like gentle waves rather than camel humps, and the varying voltage is quite minimal compared to the rectified output. | ||
- | C3 and C5, the 2.2 mF capacitors perform a smoothing operation. When the voltage starts on its downward drop from +9 V to 0 V, the capacitors discharge, and the voltage drop is minimized. The DC waveform looks a lot smoother, and more like gentle waves rather than camel humps, and the varying voltage is quite minimal compared to the rectified output. | ||
==== Regulated Voltage ==== | ==== Regulated Voltage ==== |