Bob Blick pointed me to a discrete H-Bridge on his site that might fill the bill. I'm going to look into it. --Lawrence ----- Original Message ----- From: "Spehro Pefhany" To: Sent: Wednesday, August 29, 2001 11:46 AM Subject: Re: H-Bridge Crowbar (was PIC reseting due to relays) > At 10:29 AM 8/29/01 -0500, you wrote: > > > >It would be simple to add a little logic circuit to prevent both inputs from > >going high at the same time. Digikey sells a 2-input Xor gate for US$0.35, > >two of them would do the trick. $0.70 might sound cheap to you rocket > >scientists, but I build whole PC boards that cost less than that. Can > >anybody think of a simple, cheap way to implement this, say using diode > >logic or a To-92 transistor? Kind of a design challenge. > > In essence you want to force one low when the opposite one goes high. > Maybe you could use a transistor and base resistor. > > Without more information on your circuit (especially the motor voltage and > current- I'd assume it is not the same as the PIC power supply), it's really > hard to guess what you're up to. > > If you post your circuit, I'm sure we can make suggestions. > > Best regards, > > > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- = > Spehro Pefhany --"it's the network..." "The Journey is the reward" > speff@interlog.com Info for manufacturers: http://www.trexon.com > Embedded software/hardware/analog Info for designers: http://www.speff.com > Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- = > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu