I can't find any Mosfets that can handle 200-300V. The problem is not to
source them but to find a suitable part. (Keep in mind the 20A)

Thanks
Kevin


-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Bob Blick
Sent: 13 April 2002 06:44 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [EE]:High power DC switching..


> I have some high power fast switching transistors, BUV48, which I want to
> use to control a 220V DC motor using PWM. The transistor can handle 10A Ic
> and 400 Vce (hfe =8!!). My problem is that the motor draws up to 20A and
> thus I will
> need more than one of these transistors in possibly a darlington
> configuration. Please can someone help me with a circuit to control this
> current hungry motor using a pic ...

Hi Kevin,

Do you really have to use this transistor? Do you already have some
other transistors to use as drivers for them? If not, perhaps you
should consider some other transistors, I would suggest MOSFETs.
Your losses will generally be lower. Also if you do PWM you will
need a freewheel diode across the motor.

Others will likely also have suggestions. A transistor with hfe of 8
doesn't sound like a whole lot of fun.

Cheers,

Bob

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics