Re: Reverse polarity diode circuit
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one can make as complicated or simple a fix for this as possible. i know that several guys blew up their rigs by connecting the power in reverse. we needed a simple, cheap and easy to do fix.
the diode is the fuse. it costs a few pennies. i have no fuses in my junk box, i have many diodes. if i blow one up, i can replace it with another diode. ? my target builder is actually not the kit builder, but someone who is building from her junkbox. so, i go by what a junkbox might have.?
btw, talking of the chinese suppliers, i have recently bought two linear 0-30v variable voltage, variable current supplies. each for about $100. they are used to test the uBITX and BITX boards. for my own work, i have a linear power supply made out of a 5 A battery charger transformer and a hefty 78H12. it has been around for more than a decade now.
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On Tue, Dec 12, 2017 at 10:02 PM, Mike Yancey <mikeyancey@...> wrote: I also recommend a P-Mosfet in the positive line.
Acts like a diode, but with much, much lower voltage drop.
I use them in things to which *could* be reverse polarity could be applied.
Mike Y, KM5Z
Dallas, Texas
On Mon, Dec 11, 2017 at 08:17 am, Don Cantrell wrote:
Polyfuses are not difficult to find. Several manufacturers, even Littlefuse. I get mine from Jameco (P/N 199938) for 55 cents each (quan. 10).
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