> > ----- Original Message ----- > From: "al smith" > To: > Sent: Wednesday, January 14, 2004 7:18 AM > Subject: Re: [PICLIST] [EE:] Switching voltages with FETs > > > > Presently, the power supplies that I am using are Linear Tech eval > modules, > > not the final units. I just had several of these sitting around so put > them > > to good use. If what you are saying, with the FETs turned on, then I > should > > see a drop in the source voltage? Thats not the case. I'm reading around > > 1.196 reguardless of the FET's on or off. > > > Maybe it is resistance in the leads to and from your power supply. What > size/length power and ground wires are you using from your power supply to > your circuit? Did you measure directly at the power supply before? Try > doing the same test measuring right where the 1.2V is fed to the FET circuit > (+ on load resistor and - on FET source). Dropping 88mV at 2A only requires > .044 ohms which is roughly equivalent to 11 feet of 16AWG stranded copper > wire ( or about 4' of 20AWG or <2' of 24AWG). Wire resistances googled > from: http://www.cirris.com/testing/resistance/wire.html > > Nick > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.