# Constant Current Sink Work 2 How Does A Constant Current Sink Work

## Constant Current Sink Work 2 How Does A Constant Current Sink Work

How does this constant current sink actually work? Ask Question Asked 5 years ago. Active 2 years, 7 months ago. ... In conclusion, this circuit operates as a constant current sink but only within certain \\$ V_{supply} \\$, \\$ R_{collector} \\$ and transistor power limits. These operating limits must also be considered during design.

A simple constant current sink uses an op-amp with an input voltage range that extends to the negative rail, as shown in Fig. 4.4.To set the current level, a voltage reference is required. The voltage drop across a current sensing resistor is compared to the reference voltage and the op-amp output voltage rises or falls to control the current.

16/06/2012 · I built this little constant current sink - It goes from 0A to about 3A with input voltages of up to 30V. The current is ajustable in steps of about 1 mA by using a big 10-turn potentiometer.

25/08/2013 · It says 30mA constant current SINK . Does this mean that I have to connect the anode of the LED to 5v and the cathode to one of the pins ? If so , then wouldn't this mean that the PWM values would be reversed (4096 - myvalue) since when I output a high on the pin then now current flows and a low on the pin would be current flow.

For example, if the transistor has a gain of 50, then about 98% of the current thru R1 is the sink current and the other 2% is the base current. The voltage on R1 will be Vref minus the B-E drop of the transistor. At first approximation, that can be considered constant, around 700 mV.

17/02/2016 · Cozy blog video where I talk about my constant current sink project and the desulfator scientific test that's in progress. Have a cup of coffee. -- THIS VIDEO IS …

A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it.. A current source is the dual of a voltage source.The term current sink is sometimes used for sources fed from a negative voltage supply. Figure 1 shows the schematic symbol for an ideal current source driving a resistive load.

23/11/2003 · I'm getting odd results, in a constant current sink that I'm using to discharge a battery under test. The sink consists of 10 parallel elements, each is an LM317, with 12 ohm resistor. The ADJ terminal is grounded, and the output goes to ground through the 12 ohm resistor. Input is >7V but the aggregate current is about 600 mA.