30 amp h bridge driver Help

Hi,
I'm building an H bridge driver. I'm using MJ11032 NPN and MJ11033 PNP.
I want to switch them with a ttl circuit.
I'm having problems with the best interface from TTL and the power transistors.
Note: I'm going to drive 30A 12 volt DC motors. At this point no speed control just bi directional.
Can you help?

Plenty of H bridge descriptions out there on the neet. Your big problem will be that your 30A motor might need 100A or a lot more to start and will fry the transistors.

You will need a lot of heat sink since these BJT darlingtons will need to dispose of 50W each when carrying 30A! Your "12V" motor will never get more than 9V.

I'm surprised they still make those TO-3 cans, I guess some people like the retro-1970's look in their electronics.

mneary said:

I'm surprised they still make those TO-3 cans, I guess some people like the retro-1970's look in their electronics.

Click to expand...

They make them because they handle more power, the metal casing shifts heat away faster. The 2N3055 is rated at 115W, the identical plastic version only 90W.

Mind you, TO3 is a pain the bum to mount