spice foldback protection

it is all the day that I try to obtain a plot voltage V.S. currente in this small circuit that I am try to designe

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the simulator gives me error and it says that current generator does not converge the someone more expert than me knows like resolving this problem? I unfortunately am not practical of spice... and electronics in general... I have begun to use it from a few days in for construct my first little dual power supply:
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Reply to
dunsscoto2
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That circuit won't work. R7 will prevent regulating the voltage delivered to the load. For example, say your load draws 100 mA. The voltage delivered to the load will be the output of the 7805 (5 volts) minus the 2.2 voltage drop in the 22 ohm resistor. ( 22 ohms times .1 amps = 2.2 volts). If the load changes, the voltage delivered to it will change - and it will always be below

5 volts. You need to do your current sensing on the input side of this circuit, but it still fails. I suggest abandoning it altogether and using one you can find in the datasheet. But first, you *must* define how much current you want from the circuit. You can't work out the component values without that.

Ed

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Reply to
ehsjr

ehsjr ha scritto:

yes you have reason I have made the calculations newly and I have understood that he is unusable that I did not only understand because spice did not want to simulate it hour there are successful with a variable resistore as loaded I would have intentional for the escape to 5V one protection similar to this with the same currents

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I will try in an other way thanks ehsjr!

Reply to
dunsscoto2

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