I
ITSME.ULTIMATE
- Jan 1, 1970
- 0
I'd like to design a constant current load that can handle 0-5A and
resolvable to 100mA or possibly 50mA for testing the mAh capacity of
batteries.
The circuit needs to be able to pull full 5A from 0.8 to about 15v.
I will use a data logger to monitor the voltage across input terminals
and multiply the current by the time it takes from start to 0.9v per
cell to get the capacity.
I will use a precision 0.05A resistor in series for monitoring current
and I don't mind tweaking a pot to set the current.
What is the easiest way to make a load that can load a varying voltage
source with a constant current? I'd like to use 12v light bulbs or a
power transistor for dissipating the power. I would prefer the latter,
and something to control the base current to maintain a constant
collector current.
Any idea?
resolvable to 100mA or possibly 50mA for testing the mAh capacity of
batteries.
The circuit needs to be able to pull full 5A from 0.8 to about 15v.
I will use a data logger to monitor the voltage across input terminals
and multiply the current by the time it takes from start to 0.9v per
cell to get the capacity.
I will use a precision 0.05A resistor in series for monitoring current
and I don't mind tweaking a pot to set the current.
What is the easiest way to make a load that can load a varying voltage
source with a constant current? I'd like to use 12v light bulbs or a
power transistor for dissipating the power. I would prefer the latter,
and something to control the base current to maintain a constant
collector current.
Any idea?