Hi,
I'm working on a power supply in which I want to have an adjustable current limit via rotary switch. Like 10mA, 50mA, 100mA, 500mA, 1A, 1.5A. It'll use an LM317 (and then LM337 if I make an equivalent negative supply).
So the way the rotary switch works is it just swaps in a high power resistor which sets the current limit. The voltage regulator is hooked up to this and it just performs as a normal voltage regulator.
Just say I hooked up a load that draws 20A and this supply is only capable of 1.5A, other than a fuse, is there something that I could use that wouldn't be so...permanent? Resettable fuse? Something? Any other protections?
Also, I'm open to any suggestions about how to pull of a cheap and effective current limit. The way I would do it now would definitley work, but it's always going to be burning some power as it passes through the resistor regardless of whether it actually NEEDS to limit current. Maybe a transistor or something?
I don't want to make it too complicated because I have a tendency to do so on projects and it winds up being more than it's worth sometimes.
Thanks.
I'm working on a power supply in which I want to have an adjustable current limit via rotary switch. Like 10mA, 50mA, 100mA, 500mA, 1A, 1.5A. It'll use an LM317 (and then LM337 if I make an equivalent negative supply).
So the way the rotary switch works is it just swaps in a high power resistor which sets the current limit. The voltage regulator is hooked up to this and it just performs as a normal voltage regulator.
Just say I hooked up a load that draws 20A and this supply is only capable of 1.5A, other than a fuse, is there something that I could use that wouldn't be so...permanent? Resettable fuse? Something? Any other protections?
Also, I'm open to any suggestions about how to pull of a cheap and effective current limit. The way I would do it now would definitley work, but it's always going to be burning some power as it passes through the resistor regardless of whether it actually NEEDS to limit current. Maybe a transistor or something?
I don't want to make it too complicated because I have a tendency to do so on projects and it winds up being more than it's worth sometimes.
Thanks.