Hello, I am afraid the fuse in my DMM for
measuring current is blown :(
I want to determine the amount of current a project (ATtiny85) is consuming.
The power source is a 12V 1.4 AH gel battery.
The project board uses the typical 7805 regulator and also uses the 12 VDC to supply
power using a ULN2003 to drive the external
load. The external load is a 12 VDC LED module typically used on large truck trailers and is often referred to as 'side marker lights'. This module (from Walmart)
has built in resistors as the module is designed to work off the 12 VDC in a constant on mode , and there is no way to determine the connection/size of the resisters.
The LED module is ideal for my application a strobing/flashing light for the back of my mountain bike. With the 12 VDC operation
and the timing setup, it is exactly how I want it to work. Also, like to use this module based on cost and availability and the rugged design.
So, in lieu of a working Amp meter function on my DMM, I want to just place a series resistor in series with the complete load. I would just place a resistor in series with either the battery plus or negative terminals and then just calculate the current (ohms law).
My question: What would be the best value for the resistor? I am assuming the lowest value to not interfere with power to the circuit.
Thanks in advance for any suggestions.
Got to replace that darn fuse