EGR 393 Week 2 Blog - Drake Csage and Mohammad Ghallab

1. What is the role of A/B switch? If you are on A, would B still give you a voltage?

The A/B switch shows the display of the voltage.  It selects simultaneous current and voltage metering for the A B supplies.  When the position of the switch is in the A position, the meters are connected to the A supply, and same goes with the B position.  If the circuit is still on, then yes the power supply will still give you a voltage.  

2. In each channel, there is a current specification (either 0.5 A or 4 A). What does that mean?

This is the max current that is allowed to flow through each of the channels.  If the red light comes on it means that the circuit has overloaded or is close to overloading and the current or voltage should be lowered.  

3. Your power supply has two main operation modes for A and B channels; independent and tracking. How do those operation work? (Video)

In the independent mode, A and B can be set differently from each other and you can switch between the different voltages.  In the Tracking mode, the voltages track each other and will be the same.  It will be the smallest voltage set between A and B.  

4. Can you generate +30 V using a combination of the power supply outputs? How? (Photo)

Yes.  You can keep the Power Supply on independent, and set both A and B voltages to 15 Volts.  Then connecting them to the Digital Multi meter it will read 30 V.  

5. Can you generate -30 V using a combination of the power supply outputs? How? (Photo)

Yes.  Using the same setup that was used in number 4, switch the clips.  This will change the polarity and make the voltage negative.

6. Can you generate +10 V and -10 V at the same time using a combination of the power supply outputs? How? (Photo)

Yes.  By setting the output to series, and the voltage to a set such as A to 10 Volts, you can generate +10 and -10 just by switching the terminals and changing the polarity.  

7. Apply 5V to a 100 Ω resistor and measure the current by using the DMM. Compare the reading with the current meter reading on the power supply. At what angle of the current knob makes the LED light on? If you keep on decreasing the current limit, what happens to the voltage and current? (Video)

 Using the 82Ω resistor we used Ohm's law to prove that the current for 5 volts was 60.9 mA.  The angle of the current knob that makes the LED light on is 180 degrees from the positive x-axis.  If we keep decreasing the current, the voltage goes down along with the current.  

8. Where is the fuse for the power supply? What is it for?

There are three fuses.  Two fuses are in the front and one is in the back.  The fuse is a safety feature if the current goes higher than it is rated, then the fuse will trip and not allow anymore power to go through.  It will save the machine and not blow the circuits. 

9. Where is the fuse for the DMM? What is it for?

The fuse is in the front.  It is a safety feature that will save the machine and not override the circuits if the current is too high.  

10. What is the difference between 2W and 4W resistor measurements?

The 2W and 4W resistor measurements are all about accuracy.  The 4W is a more accurate measurement because you are measuring the voltage and current at the same time, and not adding the resistance of the W to the resistor.  The 2W adds it's own resistance to the circuit so it will have some sort of % error to it.  .  

11. How would you measure current that is around 10 A using DMM?

On the Digital Multi Meter there is a spot that is 2A max measurement and a spot that is 15A max measurement.  To measure current connect the wires to the 15A max and COM, then break the circuit so it is in series and the current will flow from the circuit to the multi meter and give you your current measurement.