Hello everyone !
I have a problem with my circuit, in the simulation it seems normal, but when i wired everything , the blinking speed went up when i added the mosfet, for exemple when i use only the NE555 directly to the led, the led blinks once every 3 secondes , but when i use the mosfet, i had like 1-2 blinks/seconde, i tried removing/replacing the 1M ohm resistor but the same problem,i then tried putting a resistor between the NE555 and irf (pin 3 to gate) but then i had another problem... the led doesn't light up directly but there is a "transition phase" where the led starts lightening slowly first and then it lights up,i'm looking for a solution if anyone can help ^^ (sorry for my english btw).

 

What is the value of VR1?

ak

 

50K

 

Is the circuit on a breadboard? If so, there may be a poor connection to the FET.
Did you confirm the FET pinout is correct?
1meg seems much too high for R5. Try, say, 10k.

 

The connection is correct, i'm connecting everything on a breadboard before soldering , as for the R5 i tried 1K, 100 ohm, 4.7k, and a potentiometer 50K (i tested it from 0 -> 50K )

 

Try adding some decoupling capacitors. I suggest a 100 nF CLOSE to the 555 and a 47 uF. Also adding a resistor (Say 47 ohms ) between pin 3 of the 555 anf the gate of the mosfet. The current pulse when the 555 tries to charge the gate source capacitance of the mosfet it could be putting a negative pulse on the supply line. You could also try adding a decoupling capacitor to pin 5 of the 555 (Between 10 and 100 nF.)

Les.

 

for exemple when i use only the NE555 directly to the led, the led blinks once every 3 secondes , but when i use the mosfet, i had like 1-2 blinks/seconde

Shouldn't make any difference.

If English is difficult for you, write in your native language, using correct grammar, and run it through a translator.

 

Thanks everyone, it seems like adding a 100ohm resistor between the NE555 and irfz44 was enough!