I have been given a single IRFD9120 to use to switch a 35mA load that is a small tracking unit. Before I build or try to build the circuit I want to test the P cannel Mosfet.

As I only have 1 I want to make sure I have the right test circuit. From there I can build the final circuit. Could it be checked and I will be only to happy for any advice

 

I doubt 91K will light the LED.
Try a 330 R one

 

I doubt 91K will light the LED.
Try a 330 R one

Sorry that was a stupid error on my behalf. is the rest of the circuit in order

 

nope, you have the mosfet backwards. See that little diode drawn inside the mosfet? That really is present inside, and would conduct regardless of what is on the gate of the mosfet.
Also the resistor and switch are wrong, the resistor should be connected between source and gate of the mosfet, and the swtich between ground and gate. Also the value of the resistor should be 10-100 times lower.

 

nope, you have the mosfet backwards. See that little diode drawn inside the mosfet? That really is present inside, and would conduct regardless of what is on the gate of the mosfet.
Also the resistor and switch are wrong, the resistor should be connected between source and gate of the mosfet, and the swtich between ground and gate. Also the value of the resistor should be 10-100 times lower.

This is a P-Chanel Mosfet?

 

nope, you have the mosfet backwards. See that little diode drawn inside the mosfet? That really is present inside, and would conduct regardless of what is on the gate of the mosfet.
Also the resistor and switch are wrong, the resistor should be connected between source and gate of the mosfet, and the swtich between ground and gate. Also the value of the resistor should be 10-100 times lower.

I have changed the drawing?

 

I have changed the drawing?

No you haven´t.

 

No you haven´t.

Sorry uploaded the orginal

 

The mosfet is stil upside down. Otherwise it seems ok.

 

The mosfet is stil upside down. Otherwise it seems ok.

The symbol for the P-Chanel Mosfet I get from the symbol Library of Proteus 8 professional

 

Well that doesn´t really matter where you got it, but you need to connect source to +12V and drain towards the LED, not the other way around.

 

Well that doesn´t really matter where you got it, but you need to connect source to +12V and drain towards the LED, not the other way around.

I am totally confused now. I have changed the drawing is this right ?

 

no, leave the transistor where it was, but flip it upside down, so that source goes towards the supply voltage and drain towards the diode.

 

no, leave the transistor where it was, but flip it upside down, so that source goes towards the supply voltage and drain towards the diode.

Thank you, Its now making sense

 

Yes, now it is correct.