Week 2

Daniel Bruce and Moaad Alzahrani

Week 2

(1/16/17-1/20/17)

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

A/B switch role is to switch the display between A and B. Yes, it will still give voltage in both A and B.

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

The current specifications are maximum currents provided. Channels A and B provide a maximum of .5 Amps. The fixed channel provides a maximum of 4 Amps.

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

video 3.1 shows how the two operation modes work in the power supply.

Independent allows independent adjustments of the current and voltage of channel A and B. Neither the setting on A or B results in a difference in the other channel.

Tracking allows channels A and B to be controlled only by A, in this mode channel B "tracks" channel A. It also allows either double the voltage (series tracking) or double the current (parallel tracking). In tracking the adjustments made in channel A also apply for channel B, giving you two equal channels.

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

Figure 4.1: Using series tracking mode to provide +30V

We were able to generate +30V by switching the power supply to series tracking and connecting the multimeter test leads to the positive port of channel A and the negative port of channel B.

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

Yes we can generate -30V using a combination of the power supply outputs, we did it by using the same method as generating +30V, but we switched the leads of the mulimeter.

Figure 5.1: Generating the -30V using series tracking of the power supply outputs.

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

Yes, we did it by using A and B together with the series tracking function. We let + B and - A to be grounded, and then we measured twice. 

Figure 6.1: Photo of +10 V connections using series tracking

The first connection made with the multimeter to the + A and to the ground to get the +10V.

Figrue 6.2: Photo of -10 V Connections using series tracking

The second connection was made by connecting the multimeter to the - B and to the ground to get the -10V.

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) 

Video 7.1: Showing the effect of adjusting current with 5V on a 2K ohm resistor

We did not have a 100 ohm resistor available, so we used a 2K ohm resistor. Only a slight turn clockwise (maybe 20 degrees) of the current knob makes the LED light turn on. When we decreased the current limit the LED light turns off and the voltage stabilizes to almost 5V and the current drops to near zero Amps.

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

It is located in rear panel. It is for protecting the power supply, and the user from any damage or danger. In the event of malfunction of the unit causing too much current flow, the fuse will blow preventing any more current flow.

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

It is located in the bottom of the DMM in the left side. It is like a safe guard, that protect the multimeter from any overload.

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

The four wires is more accurate than the two wires. That’s due to the fact that we use two wires connected to the multimeter with 2W, but we connect four wires with the 4W. Two of the wires apply a small current, the other two leads sense the voltage. This removes the margin of error that the current running through the leads creates resistance, throwing the measurement off in a 2W measurement. 

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

You can switch the red lead of the DMM to the bottom red port next to the fuse on the front panel, and then use the same black port as you would for lower current measurements. This configuration provides measurements up to 15A.