After yanking out the hardwire kit, I decided to do some testing on it to see how good the power regulator performs.
First, the obligatory images of the PCB
According to the post here by @Rayman.Chan , the regulator is suppose to be able to handle 5V@2A max (please correct me if I'm wrong). Not wanting to melt the regulator, I stop the testing at 1.5A.
A regulator is suppose to be able to maintain a stable output voltage from the lowest to the maximum load current rating. Most vendor would give a 10% tolerance, while very good design would specify a 5% tolerance. For the best regulators, it would be 1% tolerance. Assuming a 10% tolerance on this regulator, this means the output should swing from 4.5V to 5.5V.
Well, what I expected and the actual outcome is a little different. Again, I stop at 1.5A for safety concern. From the graph below, when the regulator just power up, the output voltage is 5.4V, well within the expected tolerance of 10%. But, at 1.5A, still below the 2A rating, the output voltage has already dropped to 4.3V, below the expected 4.5V. This implies the regulator is probably a 15% - 20% tolerance.
This is not that bad. According to @Rayman.Chan , the CAM should normally draw 700mA, which means during the operating time, the output voltage is at the 5V range.
Next comes efficiency of the regulator. Ideally we want a 100% efficiency, but in the real world, getting to 90% is great and 80% would be good enough. At the current load that the CAM should be consuming during normal operation, we are looking at ~77% efficiency. Not that great , but OK.
Below is the raw data collected. The posting doesn't allow fancy tables, so I'm uploading the data as an image file. So what does this data tell us. Well, the input to the hardwire kit was set to 12.8V, well above any of the possible trip voltage on the kit. At the operation current of 700mA, the CAM is consuming 3.5W, while on the input, the regulator is consuming 4.W.
Test was done using an Agilent 2902A as the 12.8V input. For the load, an Keithley 2460 was used. All voltage and current sensing was done using kelvin connection.
First, the obligatory images of the PCB
According to the post here by @Rayman.Chan , the regulator is suppose to be able to handle 5V@2A max (please correct me if I'm wrong). Not wanting to melt the regulator, I stop the testing at 1.5A.
A regulator is suppose to be able to maintain a stable output voltage from the lowest to the maximum load current rating. Most vendor would give a 10% tolerance, while very good design would specify a 5% tolerance. For the best regulators, it would be 1% tolerance. Assuming a 10% tolerance on this regulator, this means the output should swing from 4.5V to 5.5V.
Well, what I expected and the actual outcome is a little different. Again, I stop at 1.5A for safety concern. From the graph below, when the regulator just power up, the output voltage is 5.4V, well within the expected tolerance of 10%. But, at 1.5A, still below the 2A rating, the output voltage has already dropped to 4.3V, below the expected 4.5V. This implies the regulator is probably a 15% - 20% tolerance.
This is not that bad. According to @Rayman.Chan , the CAM should normally draw 700mA, which means during the operating time, the output voltage is at the 5V range.
Next comes efficiency of the regulator. Ideally we want a 100% efficiency, but in the real world, getting to 90% is great and 80% would be good enough. At the current load that the CAM should be consuming during normal operation, we are looking at ~77% efficiency. Not that great , but OK.
Below is the raw data collected. The posting doesn't allow fancy tables, so I'm uploading the data as an image file. So what does this data tell us. Well, the input to the hardwire kit was set to 12.8V, well above any of the possible trip voltage on the kit. At the operation current of 700mA, the CAM is consuming 3.5W, while on the input, the regulator is consuming 4.W.
Test was done using an Agilent 2902A as the 12.8V input. For the load, an Keithley 2460 was used. All voltage and current sensing was done using kelvin connection.