reponse et conseils pour le sparkfun day

reponse et conseil au sparkfun day

If the ADC Value on a 10-bit ADC in a 3.3V system is 362, what is the voltage on the pin?
1.166 Volts <- celle la: 362 * 330 / 1024
1166 Volts
112.3296 Volts
1.767 Volts


Your system runs on a 12V battery. You'd like to monitor the battery voltage, but the range of your analog inputs is only 0 to 5V. What would be the best resistor choice for this task? (Since you're probably in a hurry, we've calculated the ratio R2/(R1+R2) for you.)

R1 = 1K Ohms, R2 = 1K Ohms
(ratio = 0.5)
R1 = 2K Ohms, R2 = 1K Ohms
(ratio = 0.33)
R1 = 1K Ohms, R2 = 2K Ohms
(ratio = 0.66)
R1 = 1K Ohms, R2 = 10K Ohms
(ratio = 0.91)

pour les resistances, je pebnche plus pour le ratio de 0.33 car 12. 0.33 = 3.96 qui est entre 0 et 5 et donc réalisable 
[18:44:28] <|Thom|>comme ça on reste dans le Vout = Vin * ratio

In the figure above calculate the maximum power dissipated by the regulator given Vin = 12V, Vout = 3.3V, and I = 500mA. 
 4.35 watts <-- this one
 17.4 watts   
 5 amps   
 5 watts


After leaving his LectroCandle on all night Billy's  1000mAh lithium-polymer battery has lost all of its charge. Billy has to  get the battery fully charged before he goes to bed tonight so he plugs  it into his LiPoly USB Charger. If the USB Charger charges the battery  at 100mA then how long will it take to fully charge the battery?

10 hours, 1 hour,  11 hour, 100 hours?
               je  dirais 10h, pareil
               
 1/ 8 bits = 1 byte
2/  AGPS

In the figure above calculate the maximum power dissipated by the regulator given Vin = 5V, Vout = 3.3V, and I = 25mA. (la figure : http://www.sparkfun.com/tutorial/PowerandThermal/examplecircuitsmall_QUIZ.jpgmais je n'ai pas encore réussi à la voir :-( )
 4.45 watts
 0.425 watts
 2.675 watts
 0.0425 watts

Réponse : 0.0425 watts ? (ils donnent la formule au dessus : P = UI, U = Vin-Vout...)


 If the ADC Value on a 10-bit ADC in a 3.3V system is 362, what is the voltage on the pin?
<alx_g> 1.166 Volts
<alx_g> 1166 Volts
<alx_g> 112.3296 Volts
<alx_g> 1.767 Volts
pour moi c'est 1.767V  (362*(3.3/2^10))


  1/ 1 byte = 8 bits
2/ The GPS aide most commonly utilized in mobile phones with GPS capabilities is
AGPS 3/ What are the two strips on the side of a breadboard called and what are they typically used for?
Power rails, to connect power and ground to your circuit 4/ Voltage dividers are useful for:
Producing a voltage output from a resistive sensor or control 5/ Beginner Troubleshooting (Using a bench power supply, you connect 5V to the VCC via, and ground to the GND via. The current on the power supply immediately shoots up to 1.27 amps. You quickly disconnect the device. Which of the following should be your next step to troubleshoot the problem?)
Check for a short from VCC to Ground using a multimeter