CIRCUIT BOARD 2

COMPONENTS: Rectifing diodes x2, Resistors x3 R1=1kohms R2=260ohms R3= 750ohms, Capacitors x2 C15, C16= 330uF, Zener diode, Voltage regulator LM317, L.E.D white 1.8v 20mA, 12v supply.

CALCULATIONS: Vout= Vref(1+R3/R2) or Vout/Vref-1= R3/R2. 5/1.25-1=R3/R2. 3=R3/R2. R1= V/I= 5/20mA= 1000ohms.

This circuit regulates the 12v supply voltage down to 5v to send. This circuit has a zener diode to protect it from back EMF. As the 12v come through the first rectifier then into the voltage regulator, it is regulated to 5volts to the flow on into the L.E.D and out to processor via ribbon. It has a rectifier parallel to the regulator so when the capacitor is full excess voltage will flow back around the regulator to the input side. A wire is linked before the first rectifier so a 12v signal is also sent to processor via ribbon. Capacitors in parallel in the circuit collect excess voltage and charge and store voltage.

To test to check if the circuit is working voltage drop testing can be done and also available voltage. You also need to remember voltage before the regulator is 12v and after it is 5v.
My RESULTS: 1. 0.74v 2. 11.65v 3. 11.65v 4. 3.92v 5. 1.26v 6. 5.17v 7. 3.26v 8. 1.91v 9. 6.47v vd across in/out= 6.48v, in/adj= 7.73v, out/adj= 1.25v. All these results tell me that the circuit is fine. Because the circuit is mostly parallel you would expect to have close to supply voltage across the components before the regulator and after the regulator 5volts across the components or adding up to 5volts if in series. eg. R1 and LED1. R1 was 3.26v and LED1= 1.91v. Both added equaled around 5v. The voltage drop across 1 meant the rectifing diode is working well. If it was high means there is high resistance in the diode.

I had no problems with my circuit board 2. The tests come up fine, there were no bad soldering connections. It worked good with output readings of 12.08v and 5.17v.

If I had a chance to make the board again I would compact it more because it is abit to spaced out. Maybe design it in a different shape because it is to long and rectangle. Maybe design it into a small square shape would be a good design if it doesn't get to hot being so compact.