[catsoup]

what exactly is
MBR1045 - SCHOTTKY BARRIER RECTIFIERS 10 AMPERES 20 to 45 VOLTS

that

is it something that will work as a schottky diode for a pimeta D1?

thanks so much.

 

[ericj]

It's a TO-220 case schottky diode. Rated for 45v reverse voltage and 10 amps.

It'll work for the pimeta, but it's major overkill and a bit large.

It also has a forward voltage drop of .84 volts, a little higher than the average 1n4001, which defeats the purpose of using a schottky diode in-line on the power supply for polarity protection in a low-voltage device.

As a crowbar, it'd work fine. A bit big, but it'll react quickly and won't be damaged by nearly any supply your pimeta gets hooked to.

 

[catsoup]

as a crowbar, is a heatsinc neccisary? or in any case in that situation? in line is it?

 

[ericj]

No. in the pimeta it will never be an issue.

if you were building a high speed switchmode power supply, then yes.

 

[mono]

Quote:

Originally Posted by ericj It also has a forward voltage drop of .84 volts, a little higher than the average 1n4001, which defeats the purpose of using a schottky diode in-line on the power supply for polarity protection in a low-voltage device.

This high-power diodes are rated for voltage drop at near (or at) max current. It does not have 0.84V drop at the lower currents, is more typical of other schottkys like around 0.4V @ 1A or even less at lower current.

It is overkill though, and probably doesn't fit the holes on the Pimeta PCB without some coaxing.

 

[dhp]

correct me if I'm wrong, but the 1N4001 would work ok for your application

 

[mono]

1N4001 would work to the extent that it's a diode, but the larger the drop, the more reverse voltage potential remains connected in reverse polarity to the rest of the amp. Also it's a bit marginal at 1A rating (higher peak but I forget what the peak rating or duration is). For many battery packs, it's pretty easy to exceed 1A.

Using ~9V battery(s), 1A might be enough, but larger cells should easily go past 1A drain. I tend to think one of Tangent's recommendations, a 1N5822 is probably the better choice here as it gets sufficiently high voltage and 3A sustained current rating plus it's not tall like that TO220 diode mentioned previously, though after looking at the Pimeta PCB I was wrong about the lead spacing, it will fit as Tanget has a generous # of holes to accomodate quite a few different diodes down to 0.2" lead spacing.