Hi All,
I was asked if i can use a picaxe to monitor that status of a 48V power supply (and maybe also 12V and 24V supplies too)
So, my initial thought was to feed the 48V into a simple voltage divider to then present 0-5V to the picaxe analog-input.
I figured the divider to be 100K and 10K in series between 48V and GND, with the divider 'tap' at the junction of the 2 resistors to feed into the analog input.
The 48V needs to be monitored in "at least" 100mV increments, so the resulting display would show something like 47.9V or 48.2V etc.
My initial calculations for a 48V is that 48V = 480 x 100mV "steps", and that 5volts (limit of picaxe analog-input) divided by 480 = 10.4mV per 'step'.
If i average the result to a nice round 10mV per division, that means 0 to 48V under test, equates to becoming 0 to 4.8V on the Analog-input.
If all goes to plan, the resulting 0-5V data value would be sent to a 7-segment display, probably via an LM7219 7-seg SPI driver chip etc.
Am i on the right track so far? and does it seem achievable for the picaxe to resolve 10mV steps accurately? or is this a bit too fine a tolerance?
Thanks in advance,
Marty.
I was asked if i can use a picaxe to monitor that status of a 48V power supply (and maybe also 12V and 24V supplies too)
So, my initial thought was to feed the 48V into a simple voltage divider to then present 0-5V to the picaxe analog-input.
I figured the divider to be 100K and 10K in series between 48V and GND, with the divider 'tap' at the junction of the 2 resistors to feed into the analog input.
The 48V needs to be monitored in "at least" 100mV increments, so the resulting display would show something like 47.9V or 48.2V etc.
My initial calculations for a 48V is that 48V = 480 x 100mV "steps", and that 5volts (limit of picaxe analog-input) divided by 480 = 10.4mV per 'step'.
If i average the result to a nice round 10mV per division, that means 0 to 48V under test, equates to becoming 0 to 4.8V on the Analog-input.
If all goes to plan, the resulting 0-5V data value would be sent to a 7-segment display, probably via an LM7219 7-seg SPI driver chip etc.
Am i on the right track so far? and does it seem achievable for the picaxe to resolve 10mV steps accurately? or is this a bit too fine a tolerance?
Thanks in advance,
Marty.