I assembled the circuit. I used 2N5401 and L3803V transistors. It works only without a capacitor! With capacitor this circuit don't work.
Butt! if add shottkey diode - circuit resolved - working with big capacition:
Welcome to the forum
What is the circuit intended to do ?
for power supply switching, load - high capacity
Neither of the above is helpful. How big is a 'big' capacitor? What is the actual load?
As best I can tell the circuit will work, whether it will work in your case is impossible to say without information about what you are doing. The real test is to build it and try it.
Can you describe the function of that circuit in words:
Is this intended to latch on for some seconds after the button is pressed or have a slow start up?
What is the part number of the Mosfet ?
What is the load (in amps) ? You have shown a lamp as the load.
For a circuit which appears to drive a 12 volt load using an N channel mosfet, it seems rather complex.
Doesn't work with no capacitors.
Hi, @kirvoboy
Welcome to the forum.
It looks like you are trying to make a latching switch.
Do you want the switch to toggle the lamp ON and OFF?
Tom.... 
ON/OFF circuit, when on input exists big capacitor (about 10 000 mkF). realy this circuit not stabile work for this variant.
all ok, for comutation supply simples circuits, but big capacition on circuits inputs. curents not big, maximum 2 ampere. but need comutation work also without or very small currents. mosfet standart IRFZ44
Without actually building the circuit I cannot for sure say it will work, but it looks good to me.
about 10 000 mkF
To be clear I think you mean 10000 microfarads. 10000μF will look like a short circuit when the MOSFET turns on, the initial inrush current will be limited only by the capability of the power supply, the Rds on of the MOSFET and the resistance of the wiring. The IRFZ44 has a pulsed drain current of 200A, so I guess it will be OK. At this point the best I can offer is so say I think it will work OK, but you need to build it and try it. Others here might have a more certain opinion.
I assembled the circuit. I used 2N5401 and L3803V transistors. It works only without a capacitor! With capacitor this circuit don't work.
ok.
A Germanium transistor?
me mistake, not, 2N5401 it's a silicon
Hi, @kirvoboy
Do you have a DMM? Digital MultiMeter?
If so then use it to check voltages around your circuit in both configurations.
If you do not have a DMM, I highly recommend you look o buying at least a low cost DMM, to help you with your projects.
Tom....
Where did this circuit come from.
Some resistor values don't add up or are highly dependent on the gain of the BC558.
They might require a BC558B or BC558C.
If I'm looking at the flat side of the BC558 in post#1 then you have the transistor mounted backwards.
Leo..
last configuration work normal, with diode.
but work 3 - 8 volts, for higher need change resistors.
: www.youtube.com/watch?v=JANTW6dGpeY
realy must work all transistors; 2N5401, all BC558, S8550..
Concerned about the gain of the transistor with 470k base resistor, not the type.
Only a BC558 with a letter behind is is binned for gain.
Did you check the orientation.
If the markings of the transistor are facing up in the image with the girl, then the emitter is connected to the gate, which is wrong.
Leo..
transistor 2N5401 h21e = 200. all pins connected right. colector set to gate. Of course, there are transistors with low gain, they may not be enough. but this circuit work 3 to 8 volts,
for higher need change resistors. I will check later.
