Current-Limiting Circuit. A current-monitoring circuit protects a 28-Vdc power supply against an overload. The current-limiting element in this circuit consists of a pair of power metal oxide/semiconductor field-effect transistors (MOSFET's).
9. I'm trying to limit a current of a 5V power supply to 100uA. I first thought of putting in a 50k resistor. That will never allow above the threshold. Unfortunately, the load requires at least 4.5V and varies in the amount of current in needs. So this is obviously a too simple approach for the problem. I am building a power supply with LM723 and my intention is to have 0-30V and a range of 0-5A variable. I am regulating voltage normally, however for current limiting, if I want to regulate small current amounts like 10mA, 100mA I need a shunt resistor with high value, which is not viable for 5A, since with LM723 I need a 0.67V voltage drop to limit current. The maximum load current a Power Supply was designed to provide under specified conditions. Remote Shut Down: When the temperature limit is exceeded, the power supply will switch off to prevent damage. The unit might seem hot, but that is normal. For maximum stability, we let the heat sink temperature rise first and then stabilize it with a it is easier for an over-current event to occur. If the power supply starts to hiccup once there is an over-current, it Vo A I 1/3IMAX IMAX A B C Vo I IMAX Figure 1: I-V curve for a power supply with maximum current limiting Figure 2: I-V curve of a power supply with current foldback .power supply with current limit
