Switching circuit for switched reluctance motor

[nothing909]

Homework Statement

I have to design a switching circuit for a switched reluctance motor. Does this look like it will work. Any changes to me made?

The components are:

Open collector - 74LS06N
IGBT - stgp6nc60hd
Optocoupler - TLP 251

 

[gneill]

The general circuit layout looks reasonable.

How did you select the 350 Ω resistance for the TLP's LED? Is 350 Ω a standard resistor value that you can source, or will you have to build it up from multiple parts? Could you have chosen an easily available single standard resistance and still satisfy the TLP's operating requirements? What calculations might you do to check? What are the relevant data values from the datasheet?

Check the TLP datasheet schematic on page 1. Are you missing any required external components?

 

[nothing909]

When you say am I missing any required external components, are you talking about the capacitor that needs to be connected between pins 8 and 5?

 

[gneill]

When you say am I missing any required external components, are you talking about the capacitor that needs to be connected between pins 8 and 5?

Yes.

 

[nothing909]

other than that, everything else looks fine?

i calculated the 350 ohm resistor by doing 5 volts - 1.8 (Vf) = 3.2 and then I did 3.2/10mA = 320 ohm. is this correct?

 

[gneill]

other than that, everything else looks fine?

Yes, I think it should okay.

i calculated the 350 ohm resistor by doing 5 volts - 1.8 (Vf) = 3.2 and then I did 3.2/10mA = 320 ohm. is this correct?

It would probably be okay and not cause any issues, but I'd probably use the "typical" values for V_F and I_F to find a resistance value, then choose the nearest standard value resistor. Best to "round upwards" if the calculated value lies near the middle of two standard values.