# 0-30V , 0-1A Constant Current & Constant Voltage Bench Top Power Supply

*0-30V , 0-1A Bench Top Power Supply With Constant Current & Constant Voltage*

*Output 0 To 30V DC**Load 0 To 1Amp**Input 40V DC @ 2Amp*

*WHAT IS CONSTANT CURRENT AND CONSTANT VOLTAGE POWER SUPPLY??*

*A Constant Voltage Power Supply*

*A constant voltage power supply will attempt to hold the target voltage no matter how much current it’s asked to source. So for simplicity’s sake, assume you have a variable resistor (a potentiometer) across the output of a constant voltage power supply and you then vary the resistance which in turn varies the amount of current drawn from the power supply. For an ideal constant voltage power supply the voltage across the variable resistor will hold constant, no matter how much current its delivering.*

*Of course actual devices will have design limits and at some point you’ll hit a current that’s more than the circuitry of the power supply can handle and at this point the voltage will start to drop and you’ll hit a maximum current. Well designed power supplies will have current limiting or short circuit protection built in to they won’t blow up if someone shorts the output terminals.*

*A Constant Current Power Supply*

*An ideal constant current power supply will deliver a constant current to the load no matter how much voltage it needs to do this. So once again for simplicity assume the same variable resistor across the output of a constant current power supply. This time assume that you set the resistance to zero – a short circuit, or very close to a short circuit. The power supply will now deliver the few millivolts or whatever is necessary to drive the specified current, say 1 amp for example.*

*Now you increase the resistance to 1 ohm. The constant current power supply will increase the output voltage to 1 volt so it can maintain the constant 1 amp current, and so on.*

*Once again, real world supplies will have design limits and at some point when the load resistance gets too high the supply will no longer be able to drive the voltage high enough to deliver the asked for current and you’ll hit a maximum output voltage.*

*Above Information Courtesy Mr. Jack Woida Information from https://www.quora.com*