[SOLVED] using Mosfet as a switch want to on and off solanoid valve.

[jay_3189]

I want to switch on and off the 6 solenoid valve. here I am doing for only 1 solenoid valve(24VDC, 0.5Amp) as shown in figure.
In previous I have done using BJT Transistor and relay but I found some problems in that.
so, here I am using IRF540 MOSFET and 8051 controller.

Here I want to know that is Diode that I have connected with MOSFET is needed?

Is register R1 and R2 needed?

Is there any other problem in this circuit?

and Also want to know that will any additional I have to use here in circuit to protect the MOSFET or Controller from more current or reverse current or voltage?

and unfortunately if my valve got sorted at that time i'm getting infinite current and 24V through FET than it got damage. so, how could I protect that?

 

[Ogu Reginald]

The diode you made mention is acting as a free wheeling diode (read about it).
You know most microcontroller operate on 5V supply ans since they are operating on 5V, they can not source more than 5V.
Check the datasheet of the MOSFET and get back to me. Most MOSFET need to be triggered by a voltage >8V before they can be turned ON.

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I don't know whether what I seeing is actually what you did? If it is then change it (I mean the 12V I am seeing on the 8051). The thumb nail can not be opened by my browser because of network problem.

 

[jay_3189]

The diode you made mention is acting as a free wheeling diode (read about it).
You know most microcontroller operate on 5V supply ans since they are operating on 5V, they can not source more than 5V.
Check the datasheet of the MOSFET and get back to me. Most MOSFET need to be triggered by a voltage >8V before they can be turned ON.

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I don't know whether what I seeing is actually what you did? If it is then change it (I mean the 12V I am seeing on the 8051). The thumb nail can not be opened by my browser because of network problem.

Yes its my mistake that there is 5VDC for 8051.
and about this MOSFET(IRF540) its only MOSFET which needs only 3V for triggered ON.

 

[Ogu Reginald]

In as much as the voltage divider you are using is good, at least they can give more than 4V. I prefer using 39 ohm and 2.7kohm as a voltage divider so that the it will be easy to dicharge the capacitance at the gate.

And the series resitor used for the LED should be changed to about 2kohm. Just use normal ohm's to calculate the value.