Yes, your right. I meant to say 240 times per minute, which is 4 Hz. ----- Original Message ----- From: "Nicholas Irias" To: Sent: Thursday, June 28, 2001 5:07 PM Subject: Re: [EE] Modulating a headlight > If you cant find a low Rds P-channel FET, check out the high side FET > drivers at micrel.com. They have built in charge pumps to switch an > N-channel FET at the appropriate voltage for high side switching. > > I think headlight modulating on cycles is 3 or 4 times a second. Maybe you > meant to say 240 times per minute rather than 240 Hz? > > > ----- Original Message ----- > From: "Miles McKinnon" > To: > Sent: Thursday, June 28, 2001 3:27 PM > Subject: [EE]: Modulating a headlight > > > > I am building a motorcycle headlight modulator using a PIC to monitor > > ambient light and a few other things. Anyway, the PIC has to modulate the > > headlight ( ~ 4Amps) at a arount 240Hz or so. > > > > There are a few legal stipulations. They say that you cannot switch the > > ground, you must switch the +12V to the headlight. I want to use a low > Rds > > HEXFET or simular transistor, but I think I would need a P-Channel device. > > > > Is a P-Channel Mosfet difficult to drive from a TTL logic level, such as a > > PIC. > > > > Thanks for any help. > > > > -- > > http://www.piclist.com hint: The PICList is archived three different > > ways. See http://www.piclist.com/#archives for details. > > > > > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.