1. The role of the A/B switch is to give you 2 different power supplies that can be used at the same time in series mode or just using one at a time for parallel mode. Depending on what mode you are on B could be helping A like in series if each switch is on 15V, then the total voltage will be 30V. If you are in parallel mode then B will take the voltage of A, so if A is on 5V so will B, but the voltage total will be 5V.
2. The current specification of each channel reads either .5 amps or 4 amps. This means that the current coming out of the power supply is either .5 amps or 4 amps, depending on which current you chose to use.
3. Video explanation on how the A and B channels work on the power supply unit
|Picture of the power supply setup used to find +/- 30 volts|
|DMM reading of roughly 30 volts|
5. Generating -30 volts with the power supply. We used the same set up as above just switched the location where we measured.
|DMM reading of roughly -30 volts|
6. Generating 10 volts and -10 volts at the same time
|Power supply setup to display +/- 10 Volts|
|DMM reading of roughly 10 volts|
|DMM reading of roughly -10 volts|
7. Video showing how removing current affects the circuit. When the current knob is turned almost entirely to the left (CCW) the LED turns on and the voltage drops to 0 volts. Therefore, the DMM reads 0 amps for the current as well. This is a simple application of Ohms law.
V=I x R
If 'I' is zero V is also 0
8. The fuse for the power supply is located at the back of the power supply where you would plug in the power cord. It is used to protect the user and the machine from damage.
9. The fuse for the DMM is located at the bottom left of the input/output plugs. The fuse is used as a backup to the user and machine to make sure that they don't get hurt when there is too much voltage.
10. 2W is used more for Lead Resistance and has some limitations compared to the 4W. The 4W (Kelvin) Resistance is used more for low resistance measurements. It also has less limitations than the 2W when being used for low resistance.
11. To measure a current using the DMM we would move the positive cord to the right of the fuse instead of its original position of being above the fuse. We would also keep the negative cord in its normal position which is top diagonal of the fuse.