Ne555 output to igbt gate with isolation

Thread Starter

captainssbn

Joined Sep 24, 2012
9
Hi All
I need some help with my motor controller design. I have an NE555 output of 2.5ms or less pulse that needs to turn on an IGBT Gate. I need the circuit to be isolated from the NE555 circuitry. How can I use an Opto Isolator to do this? I have some IXDD614 drivers Ua7815 power Ics. also available is a power transformer output of 30VAC. the NE555 circuitry is using the other transformer output to get 15vdc. So the second transformer output I think will give me an isolated DC needed in the Opto output and driver circuitry.

Does anyone have a working schematic?

Capt
 

Dodgydave

Joined Jun 22, 2012
9,169
'Why cant you use a Mosfet to drive the output instead of an IGBT, that way you don't need a gate drive resistor, have you got a diagram of your circuit?


or if you need to use an opto , which seem a waste of time, then use a 4N35 series
 
Last edited:

ian field

Joined Oct 27, 2012
6,539
'Why cant you use a Mosfet to drive the output instead of an IGBT, that way you don't need a gate drive resistor,

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The gate of an IGBT is pretty much identical to the gate of a MOSFET, the device is pretty much a MOSFET and an emitter follower in the same package. The IGBT was developed to overcome high RDSon of early MOSFETs, but its slow in comparison and modern MOSFETs have pretty impressive RDSon now.
 
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