High current Diode (50 amps)

Other Hardware Motors, Mechanics, Power and CNC
1

Hello Forum,

I am trying to isolate a AC to DC power supply and a lead acid battery for a large robot. I am looking for two diodes to isolate each supply. System voltage will be at 12 volts. I expect a continuous 50 amps to be used at times and a peak of about a 100 amps for around 5-10 seconds max.

I attempted to search on the eBay and Amazon but I can't find any diodes that can take that much current.

I am looking for a recommendation on what diode to get and where to get it from.

Thank you for your help

2

Forget eBay and Amazon. Check DigiKey, Mouser, or any of the other suppliers of legitimate components.

3

Go to your local auto parts supplier and ask for "battery isolator diodes".

Paul

4

For instance: http://uk.farnell.com/vishay/vs-100bgq100/schottky-rectifier-100a-100v-powertab/dp/2690127

It strikes me this might be an application for ideal diodes - at these current levels you get an ideal
diode controller that drives a MOSFET. I'm not sure how these devices interact when running
side by side at nearly the same voltage though, they might both conduct for some overlap
(they are designed to implement perfect rectifier bridges where the voltage swings at a high rate).

5

Dual diode battery isolators are used in boats.
Try a marine shop.
Leo..

6

MarkT:
It strikes me this might be an application for ideal diodes - at these current levels you get an ideal
diode controller that drives a MOSFET. I'm not sure how these devices interact when running
side by side at nearly the same voltage though, they might both conduct for some overlap
(they are designed to implement perfect rectifier bridges where the voltage swings at a high rate).

I've seen something similar to that called an "active diode". The IC versions seem to be relatively small current - milliamps to 3A only. If low voltage drop was important then you would have to build it out of discrete components.