What is it?

Reverse polarity protection will protect your equipment when hooking up the power to it backwards.

Why did you make it?

I had an amateur radio which used the "reversed diode/fuse" method for reverse protection. Of course I'm 15 miles from civilization and hooked it up backwards with no spare fuse. There had to be a better way.

What makes it special?

The RPP board is design to be placed inside a small radio or other piece of equipment. Since the forward diode method has a large voltage drop across it, and the reverse diode/fuse method pops fuses (see above), this board uses the P-MOSFET method which effectively acts as an open circuit when the polarity is backwards and much lower loss than a diode when forward. The board also includes LED's to indicate proper (green) or reverse (red) polarity.

There are 4 variations as follows:

• Reverse Polarity Protection Thru-Hole Assembled - Fully assembled and ready to use using thru-hole components.

• Reverse Polarity Protection Thru-Hole Kit - Kit contains all the parts (resistors, caps, diode, MOSFET, LED's,PCB, and Terminal Blocks) to create a fully assembled board. Some soldering experience is required.

• Reverse Polarity Protection SMD Assembled - Fully assembled and ready to use using SMD style components.

• Reverse Polarity Protection SMD Kit - Kit contains all the parts (resistors, capacitors, diode, MOSFET, LED's, PCB, and terminal blocks) to create a fully assembled board. This kit was designed as a beginners SMD project using larger 1206 sized components with good spacing in between. To help we even include 2x the 1206 sized components.

Specifications:

• Input Voltage: 4-50VDC
• Current Load (MAX): 4.25A Max Continuous 7A Peak (Heatsink recommended but not included for max/peak levels)
• Voltage Drop:3mV@ 60mA 130mV@820mA 340mV@1.3A 900mV@5.4A