This page will attempt to go over all the test equipment that we have in the bay and provide links to user guides, etc. It goes over the basic operation, and attempts to explain it. For a much better resource, visit Dave Jones’ EEVBlog YouTube channel - there is tons of great info on there: https://www.youtube.com/user/EEVblog/playlists
Multimeter (Handheld)
The most used instrument in the bay. Everyone should be familiar with these. Measures voltage, resistance, continuity, temperature, current, among other metrics. I won’t try and rewrite the amazing tutorial made by Sparkfun, so I’ll just post the link: https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/all
Multimeter (Benchtop)
We have a benchtop multimeter that is much more accurate than the handheld multimeters. If you need high accuracy measurements, use this one. Operation is very similar.
User Guide:
Oscilloscope
The oscilloscope allows you to capture voltage waveforms over time. This is commonly used to evaluate transient events such as button pushes, PWM signals, etc.
Again, Sparkfun has an amazing guide that I won’t try to rewrite, so I’m posting the link: https://learn.sparkfun.com/tutorials/how-to-use-an-oscilloscope?_ga=2.175825314.1209979341.1580575464-225400905.1540517045
We have a Rigol DS1054Z. The user manual is posted here:
DC Load
The DC Load is used to draw current from a circuit. This can be super useful for testing circuits under full load, such as the horn driver circuit, the Solar MPPTs, and the Solar arrays, etc.
There are a few modes that the load can operate in. It works essentially as a variable resistor so that you can vary the load on a circuit. The circuit operation is the exact same for every mode, however the control loop and signals change.
Constant Current (CC) Mode
The most common mode of operation is Constant Current (CC) mode. In this mode, the load will draw as much current as it can up to the limit of the Current Set Point.
Constant Voltage (CV) Mode
In this mode, you would set the voltage that the DC Load will attempt to get to at its terminals. The load will draw as much current as necessary to make the input voltage equal to the set voltage.
Constant Wattage (CW) Mode
The load will draw as much current as necessary so that the input voltage * input current is equal to the power set point.
Constant Resistor (CR) Mode
This mode is fairly self-explanatory. The load will operate exactly as a resistor, and will have the
During any of the operation modes, be careful to not overload the max current, voltage, or power ratings of the DC Load.
User Guide:
For a closer look at the operation of the hardware, check out this great video by Dave Jones at EEV Blog that goes over the hardware design of a DC Load: https://www.youtube.com/watch?v=8xX2SVcItOA
He also does an overview of the BK Precision loads here: https://www.youtube.com/watch?v=5dNxzzuMTB8
Also interesting, here is a BK Precision application note about some of the things that you can do with DC Loads:
Power Supply
Will supply power to your boards. To set it up, the voltage and current must be set to the proper values. Power supplies operate in what it called Constant Voltage / Constant Current (CV/CC) mode.
The power supply will not output a higher voltage or a higher current than you set, and will attempt to output the maximum voltage as long as the current is less than the maximum that you set. All power supplies will have a maximum voltage and current available on their outputs, as well as a maximum power spec. They will limit the output to keep it under the maximum power even if neither the voltage or current limit set points have been hit. This is to protect the internal components of the power supply.
Most of our boards are powered from 11-13.5V and will draw very little current, on the order of a couple hundred mA on the high end. A good value to start with is 12V, 0.1A, and should cover a wide range of the boards that we use. Always double check with the specific board you are powering before turning the output on.
Power supplies can also be very useful to perform what is called a ‘smoke test’ - because everything runs on ‘magic smoke’ - if you let it out, the part won’t work. This ‘smoke test’ is performed as the first power-on of the board. Typically a very low current limit is set so that if a component was soldered wrong, then you will still notice it burn, but it won’t blow up as violently as it does not have as much power available to it.
A great tutorial by Sparkfun here: https://www.youtube.com/watch?v=uraPWaeAgYA
If you want to go a little more in depth of how power supplies work, have a look at the following videos that go through the design of a linear power supply:
https://www.youtube.com/watch?v=CIGjActDeoM
https://www.youtube.com/watch?v=6Otr1I0OR18
LCR Meter
This is less commonly used, but is super handy for measuring inductance.