Diodes

[NoHoper]

Why is cant I get diodes to work in multisim 11. Can anyone tell me why this simple half wave rectifier is not working?

[Tom__Sedlack]

Your 1K load wasn't being seen by the diode. The way you have the diode wired, it was "shorting" to the other leg of the transformer.  Your choice of diode was also an issue as it was a small signal type used at high voltage.  Also, the scope should be set to DC.

[yyao]

Hi there,

Take a look at your circuit. You have connected D2 and R2 so that there is no current flowing through R2. Thus, there is no voltage drop over R2, and you read a constant 0V from that node.

Change your circuit so that R2 is in the current loop of the secondary winding of your transformer. Also, you will have to ground a node (any node) in that loop for simulation to give you reasonable results.

I hope you aren't actually planning to build this circuit...

[NoHoper]

Thanks. I really need to get to grips with these basics before I start my new job. What should I be looking for when selecting a diode for a job like this?

[Tom__Sedlack]

There are a variety of things to look for but (for me) the biggest are forward current handling and max reverse voltage. 

[yyao]

Try something like the 1N4003 or 1N4004 to get you started.